warp drive interstellar travel

The U.S.S. Enterprise , depicted here in the 2013 movie Star Trek: Into Darkness , relies on its warp drive to zip across the galaxy.

Inside the Quest for a Real ‘Star Trek’ Warp Drive

It may be a while before starship captains can race across the galaxy, but engineers and physicists have a few ideas for making it so.

Within the Star Trek universe, traveling across the galaxy is a breeze thanks to the famed warp drive . This fictional technology allows humans and other civilizations to zoom between star systems in days rather than centuries.

Such rapid travel times are impossible in the real world, because our best theory for the way the universe works, Einstein’s special relativity , says that nothing moves faster than the speed of light.

While current rocket propulsion systems are bound by this law, plenty of hopeful engineers and physicists are working on concepts that might bring us a step closer to Star Trek ’s vision of racing across the cosmos.

“Currently, even the most advanced ideas behind interstellar travel entail trip times of decades and centuries to even the closest stars, due to the restrictions of special relativity, and our abilities—or lack of—to travel at an appreciable fraction of the speed of light,” says Richard Obousy , director and founder of Icarus Interstellar, a nonprofit dedicated to making progress toward interstellar flight.

“Being able to build starships with the capability to travel faster than the speed of light would open the galaxy for exploration and possible colonization by humans.”

Nuclear Engines

Distances in space are so vast that astronomers usually measure them in light-years, the distance light can travel in a year’s time. A single light-year equals about six trillion miles.

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The closest star to our solar system, Proxima Centauri, is 4.23 light-years away, so even traveling at the speed of light, a one-way voyage there would take 4.23 years. That may seem pokey, but it would be a huge improvement over current technology.

Right now, the fastest spacecraft headed away from Earth is Voyager 1, which is puttering along at about 38,600 miles an hour. At that rate, it would take more than 70,000 years to reach Proxima Centauri.

Still, various teams have proposed ways to at least reach a fraction of light speed and hasten our exploration of interstellar space.

Back in 1958, researchers at San Diego-based defense contractor General Atomics came up with Project Orion , which involved a spacecraft driven essentially by nuclear bombs. A controlled series of nuclear explosions would propel the ship at high speeds, rapidly carrying a hundred tons of cargo and eight astronauts to places like Mars and even the outer solar system.

Faster propulsion technology would allow us to visit our galactic neighbors, like this satellite of the Milky Way known as the Large Magellanic Cloud.

Blueprints were also created showing how to adapt the technology for interstellar travel. However, all experimentation with this so-called nuclear-pulse propulsion came to a halt with the Nuclear Test Ban Treaty of 1963.

Announced earlier this year, the ambitious Breakthrough StarShot initiative represents a less explosive effort to undertake an interstellar mission. Run by a conglomerate of billionaires and big thinkers, including famed physicist Stephen Hawking, the project’s goal is to send a flotilla of postage stamp-size spacecraft to Alpha Centauri, a triple star system that’s 4.3 light-years away. (See “Is the New $100 Million ‘Starshot’ for Real?” )

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The tiny spacecraft would be attached to a thin light sail, a piece of technology that would allow mission managers to propel the probes with lasers shining from Earth’s orbit. The lasers would accelerate the craft to 20 percent the speed of light, and the probes would arrive at their destination in roughly 20 years.

While many of the tiny travelers may never make it to Alpha Centauri, a few of them should survive and may even fly past any planets orbiting the far-off stars , beaming back data about these alien worlds.

“I’m incredibly excited to see private money being used to explore breakthrough ideas that may advance the field of interstellar flight,” Obousy says.

“I hope to see more like this in the future. While there are engineering challenges associated with the Starshot Initiative, none appear insurmountable.”

Warping Reality

Of course, the real breakthrough would be a true warp drive, which requires technology to catch up with our theoretical designs.

In 1994, Trek fans got a glimmer of hope from Mexican theoretical physicist Miguel Alcubierre, who came up with a radical theory of hyper-fast space propulsion that doesn't break Einstein’s special relativity.

Instead of accelerating the spacecraft itself to light speed, why not bend, or warp, the fabric of space and time around the ship itself? Alcubierre presented calculations that produce a bubble in space-time in which one end is expanding and the other is contracting. A spaceship could, in theory, be carried along with the warp bubble and accelerated to velocities up to 10 times the speed of light.

While that sounds simple on paper, to make it work, we may need to harness exotic forms of matter, like antimatter, that for now are poorly understood. In addition, numerous unsolved issues plague the creation and control of a warp bubble, Obousy says.

“One such problem, for example, is the idea of causal disconnection, which implies that any spacecraft sitting within the bubble would not be able to ‘communicate’ with the exterior of the bubble, suggesting that a ship would not be able to ‘turn off’ the bubble once inside of it,” he notes.

As is often the case in space travel, developing true interstellar travel like what we see in Star Trek will require significant changes in the cost and energy requirements.

“Currently, the amount of energy and money required to entertain the notion of manned interstellar travel is measured in large fractions of global output—specifically, tens of trillions of dollars, and energy measured on the scale of what many large countries use annually,” he says.

Still, he adds, “the finest minds of the 15th century could not have predicted the technological wonders of the 21st century. Similarly, who are we to say what technology the humans of the 27th century will have mastered.”

Andrew Fazekas, the Night Sky Guy, is the author of Star Trek: The Official Guide to Our Universe and host of NG Live! " Mankind to Mars " presentations. Follow him on Twitter , Facebook , and his website .

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New warp drive research dashes faster than light travel dreams – but reveals stranger possibilities

Associate professor, Australian Catholic University

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Sam Baron receives funding from the Australian Research Council.

Australian Catholic University provides funding as a member of The Conversation AU.

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In 1994, physicist Miguel Alcubierre proposed a radical technology that would allow faster than light travel: the warp drive , a hypothetical way to skirt around the universe’s ultimate speed limit by bending the fabric of reality.

It was an intriguing idea – even NASA has been researching it at the Eagleworks laboratory – but Alcubierre’s proposal contained problems that seemed insurmountable. Now, a recent paper by US-based physicists Alexey Bobrick and Gianni Martire has resolved many of those issues and generated a lot of buzz .

But while Bobrick and Martire have managed to substantially demystify warp technology, their work actually suggests that faster-than-light travel will remain out of reach for beings like us, at least for the time being.

There is, however, a silver lining: warp technology may have radical applications beyond space travel.

Across the universe?

The story of warp drives starts with Einstein’s crowning achievement: general relativity. The equations of general relativity capture the way in which spacetime – the very fabric of reality – bends in response to the presence of matter and energy which, in turn, explains how matter and energy move.

General relativity places two constraints on interstellar travel. First, nothing can be accelerated past the speed of light (around 300,000 km per second). Even travelling at this dizzying speed it would still take us four years to arrive at Proxima Centauri, the nearest star to our Sun.

Second, the clock on a spaceship travelling close to the speed of light would slow down relative to a clock on Earth (this is known as time dilation). Assuming a constant state of acceleration, this makes it possible to travel the stars. One can reach a distant star that is 150 lightyears away within one’s lifetime. The catch, however, is that upon one’s return more than 300 years will have passed on Earth.

This is where Alcubierre came in. He argued that the mathematics of general relativity allowed for “warp bubbles” – regions where matter and energy were arranged in such a way as to bend spacetime in front of the bubble and expand it to the rear in a way that allowed a “flat” area inside the bubble to travel faster than light.

Read more: Don't stop me now! Superluminal travel in Einstein's universe

To get a sense of what “flat” means in this context, note that spacetime is sort of like a rubber mat. The mat curves in the presence of matter and energy (think of putting a bowling ball on the mat). Gravity is nothing more than the tendency objects have to roll into the the dents created by things like stars and planets. A flat region is like a part of the mat with nothing on it.

Such a drive would also avoid the uncomfortable consequences of time dilation. One could potentially make a round trip into deep space and still be greeted by one’s nearest and dearest at home.

A spacetime oddity

How does Alcubierre’s device work? Here discussion often relies on analogies, because the maths is so complex.

Imagine a rug with a cup on it. You’re on the rug and you want to get to the cup. You could move across the rug, or tug the rug toward you. The warp drive is like tugging on spacetime to bring your destination closer.

But analogies have their limits: a warp drive doesn’t really drag your destination toward you. It contracts spacetime to make your path shorter. There’s just less rug between you and the cup when you switch the drive on.

Alcubierre’s suggestion, while mathematically rigorous, is difficult to understand at an intuitive level. Bobrick and Martire’s work is set to change all that.

Starship bloopers

Bobrick and Martire show that any warp drive must be a shell of material in a constant state of motion, enclosing a flat region of spacetime. The energy of the shell modifies the properties of the spacetime region inside it.

This might not sound like much of a discovery, but until now it was unclear what warp drives might be, physically speaking. Their work tells us that a warp drive is, somewhat surprisingly, like a car. A car is also a shell of energy (in the form of matter) that encloses a flat region of spacetime. The difference is that getting inside a car does not make you age faster. That, however, is the kind of thing a warp drive might do.

Using their simple description, Bobrick and Martire demonstrate a method for using Einstein’s general relativity equations to find spacetimes that allow for arrangements of matter and energy that would act as warp bubbles. This gives us a mathematical key for finding and classifying warp technologies.

Their work manages to address one of the core problems for warp drives. To make the equations balance, Alcubierre’s device runs on “negative energy” – but we are yet to discover any viable sources of negative energy in the real world.

Worse, the negative energy requirements of Alcubierre’s device are immense. By some estimates, the entire energy in the known universe would be needed (though later work brings the number down a bit).

Bobrick and Martire show a warp drive could be made from positive energy (i.e. “normal” energy) or from a mixture of negative and positive energy. That said, the energy requirements would still be immense.

If Bobrick and Martire are right, then a warp drive is just like any other object in motion. It would be subject to the universal speed limit enforced by general relativity after all, and it would need some kind of conventional propulsion system to make it accelerate.

The news gets worse. Many kinds of warp drive can only modify the spacetime inside in a certain way: by slowing down the clock of the passenger in exactly the way that makes a trip into deep space a problem.

Bobrick and Martire do show that some warp drives could travel faster than light, but only if they are created already travelling at that speed – which is no help for any ordinary human hoping for a bit of interstellar tourism.

The end game

Remember that a warp drive can modify the region of flat spacetime it encloses. It can, in particular, speed up or slow down a clock inside the drive.

Consider what it would mean to have such an object available. Want to put someone with a terminal illness on ice? Stick them in a warp drive and slow their clock down. From their perspective, a few years will pass, while a hundred years will pass on Earth — time enough to find a cure.

Read more: The art and beauty of general relativity

Want to grow your crops overnight? Stick them in a warp drive and speed the clock up. A few days will pass for you, and a few weeks will pass for your seedlings.

There are even more exotic possibilities: by rotating the spacetime inside a drive one may be able to produce a battery capable of holding huge amounts of energy.

Faster-than-light travel remains a distant dream. But warp technology would be revolutionary in its own right.

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A functioning warp drive would allow humans to reach the far ends of the cosmos in the blink of an eye.

White and his team in LSI’s Houston laboratory were conducting research for the Defense Advanced Research Projects Agency, or DARPA, and had set up these particular experiments to study the energy densities within Casimir cavities, the mysterious spaces between microscopic metal plates in a vacuum. The data plot indicated areas of diminished energy between the plates, which caused them to push toward each other as if trying to fill the void. This is known as negative vacuum energy density, a phenomenon in quantum mechanics called, appropriately enough, the Casimir effect . It’s something that’s helping scientists understand the soupy physics of microscale structures, which some researchers hope can be applied to energy applications that are more practical, such as circuits and electromechanical systems.

But White noticed that the pattern of negative vacuum energy between the plates and around tiny cylindrical columns that they’d inserted in the space looked familiar. It precisely echoed the energy pattern generated by a type of exotic matter that some physicists believe could unlock high-speed interstellar travel. “We then looked, mathematically, at what happens if we placed a one-micron sphere inside of a four-micron cylinder under the same conditions, and found that this kind of structure could generate a little nanoscale warp bubble encapsulating that central region,” White explains.

That’s right—a warp bubble. The essential component of a heretofore fictional warp drive that has for decades been the obsession of physicists, engineers, and sci-fi fans. Warp drive, of course, is the stuff of Star Trek legend, a device enclosed within a spacecraft that gives the mortals aboard the ability to rip around the cosmos at superhuman speed. To the lay sci-fi fan, it’s a “black box”—a convenient, completely made-up workaround to avoid the harsh realities of interstellar travel. However, after decades of speculation, research, and experimentation, scientists believe a warp drive could actually work.

To emphasize: White didn’t actually make a warp bubble. But the data from his study led to an aha moment: For the first time, a buildable warp bubble showed promise of success.

Warp technology’s core science is surprisingly sound. Though the specific mechanics of an actual device haven’t been fully unpacked, the math points toward feasibility. In short, a real-life warp drive would use massive amounts of energy, which can come in the form of mass, to create enough gravitational pull to distort spacetime in a controlled fashion, allowing a ship to speed along inside a self-generated bubble that itself is able to travel at essentially any speed. Warp drives popped up in fiction intermittently for several decades before Star Trek creator Gene Roddenberry plugged one into the USS Enterprise in 1966. But Miguel Alcubierre, PhD, a Mexican theoretical physicist and professed Star Trek enthusiast, gave the idea real-world legs when he released a paper in 1994 speculating that such a drive was mathematically possible. It was the first serious treatment of a warp drive’s feasibility, and it made headlines around the world. His breakthrough inspired more scientists to nudge the theoretical aspects of warp drive toward concrete, practical applications.

“I proposed a ‘geometry’ for space that would allow faster-than-light travel as seen from far away, essentially expanding space behind the object we want to move and contracting it in front,” Alcubierre says. “This forms a ‘bubble’ of distorted space, inside of which an object—a spaceship, say—could reside.”

Physicists tend to speak in relative terms. By injecting the sly qualifier “as seen from far away,” Alcubierre might sound like he’s describing the galactic equivalent of an optical illusion —an effect perhaps similar to driving past a truck going the opposite direction on the highway when you’re both going 60 miles an hour. Sure feels like a buck-twenty, doesn’t it? But the A-to-B speed is real; the warp effect simply shortens the literal distance between two points. You’re not, strictly speaking, moving faster than light. Inside the bubble, all appears relatively normal, and light moves faster than you are, as it should. Outside the bubble, however, you’re haulin’ the mail.

.css-2l0eat{font-family:UnitedSans,UnitedSans-roboto,UnitedSans-local,Helvetica,Arial,Sans-serif;font-size:1.625rem;line-height:1.2;margin:0rem;padding:0.9rem 1rem 1rem;}@media(max-width: 48rem){.css-2l0eat{font-size:1.75rem;line-height:1;}}@media(min-width: 48rem){.css-2l0eat{font-size:1.875rem;line-height:1;}}@media(min-width: 64rem){.css-2l0eat{font-size:2.25rem;line-height:1;}}.css-2l0eat b,.css-2l0eat strong{font-family:inherit;font-weight:bold;}.css-2l0eat em,.css-2l0eat i{font-style:italic;font-family:inherit;} THOUGH THE SPECIFIC MECHANICS OF AN ACTUAL DEVICE HAVEN’T BEEN UNPACKED, THE MATH POINTS TOWARD FEASIBILITY.

Alcubierre’s proposal had solved one of the initial hurdles to achieving warp speeds: The very idea clashes with Einstein’s long-accepted theory of general relativity, which states that nothing can travel faster than the speed of light, but it doesn’t preclude space itself from traveling faster than that. In fact, scientists speculate that the same principles explain the rapid expansion of the universe after the Big Bang .

While concluding that warp speed was indeed possible, Alcubierre also found that it would require an enormous amount of energy to sustain the warp bubble. He theorized that negative energy—the stuff hinted at by White’s experimentation with Casimir cavities—could be a solution. The only problem is that no one has yet proved that negative energy is real. It’s the unobtanium of our spacefaring imaginations, something researchers only believe to exist. In theory, however, this unknown matter may be sufficiently powerful that future warp drive designers could channel it to contract spacetime around it. In conceptual drawings of warp-capable spacecraft , enormous material rings containing this energy source surround a central fuselage. When activated, it warps spacetime around the entire ship. The more intense the warping, the faster the warp travel is achieved.

Of course, it’s not that simple. Physicist José Natário, PhD, a professor at the Instituto Superior Técnico in Lisbon, wrote his own influential paper about the mathematical feasibility of warp drives in 2001. However, he is concerned about practical conundrums, like the amount of energy required. “You need to be able to curve spacetime quite a lot in order to do this,” he says. “We’re talking about something that would be much, much more powerful than the sun.”

Alcubierre is similarly skeptical that his theoretical ideas might ever be used to develop a working warp drive. “In order to have a bubble about 100 meters wide traveling at precisely the speed of light, you would need about 100 times the mass of the planet Jupiter converted into negative energy, which of course sounds absurd,” he says. By that standard, he concludes, a warp drive is very unlikely.

Physicists love a challenge, though. In the 29 years since Alcubierre published his paper, other scientists have wrestled with the implications of the work, providing alternative approaches to generating the energy using more accessible power sources, finding oblique entry points to the problem, and batting ideas back and forth in response to one another’s papers. They use analogies involving trampolines , tablecloths, bowling balls, balloons, conveyor belts, and music to explain the physics.

They even have their own vocabulary. It’s not faster-than-light travel; it’s superluminal travel, thank you. Then there’s nonphysical and physical—a.k.a. the critical distinction between theoretical speculation and something that can actually be engineered. (Pro tip: We’re aiming for physical here, folks.) They do mention Star Trek a lot, but never Star Wars . Even the scruffiest-looking nerf herder knows that the ships in Star Wars use hyperdrive, which consumes fuel, rather than warp drives, which don’t use propulsive technology but instead rely on, well, warping. They’re also vague about details like what passengers would experience, what gravity is like on board since you’re carrying around boatloads of energy, and what would happen if someone, say, jumped out of the ship while warping. (A speculative guess: Nothing good.)

Such research isn’t typically funded by academic institutions or the DARPAs and NASAs of the world, so much of this work occurs in the scientists’ spare time. One such scientist and Star Trek enthusiast is physicist Erik Lentz, PhD. Now a researcher at Pacific Northwest National Laboratory in Richland, Washington, Lentz was doing postdoctoral work at Göttingen University in Germany when, amid the early, isolated days of the pandemic, he mulled the idea of faster-than-light travel. He published a paper in 2021 arguing that warp drives could be generated using positive energy sources instead of the negative energy that Alcubierre’s warp drive seemed to require.

“There are a number of barriers to entry to actually being able to build a warp drive,” Lentz says. “The negative energy was the most obvious, so I tried to break that barrier down.”

He explored a new class of solutions in Einstein’s general relativity while focusing on something called the weak-energy condition, which, he explains, tracks the positivity of energy in spacetime. He hit upon a “soliton solution”—a wave that maintains its shape and moves at a constant velocity—that could both satisfy the energy-level challenge and travel faster than light. Such a warp bubble could travel along using known energy sources, though harnessing those at the levels needed are still far beyond our capabilities. The next step, he notes, may be bringing the energy requirements for a warp drive to within the range of a nuclear fusion reactor.

A fusion-powered device could theoretically travel to and from Proxima Centauri , Earth’s nearest star, in years instead of decades or millennia, and then go faster and faster as power sources improve. Current conventional rocket technology, on the other hand, would take 50,000 years just for a one-way trip—assuming, of course, there was an unlimited fuel supply for those engines.

“IF YOU COLLIDE WITH SOMETHING ON YOUR PATH, IT WOULD ALMOST CERTAINLY BE CATASTROPHIC.”

Like Alcubierre’s original thesis, Lentz’s paper had a seismic impact on the warp drive community, prompting yet another group of scientists to dig into the challenge. Physicist Alexey Bobrick and technology entrepreneur Gianni Martire have been particularly prolific. In 2021, they released a paper theorizing that a class of subliminal warp drives, traveling at just a fraction of light speed, could be developed from current scientific understanding. While that paper essentially argued that it’s perfectly acceptable to walk before you can run, they followed it up with another theory earlier this year that describes how a simulated black hole , created using sound waves and glycerin and tested with a laser beam, could be used to evaluate the levels of gravitational force needed to warp spacetime. The duo coded that breakthrough into a public app that they hope will help more quickly push theoretical ideas to practical ones. Though the team is waiting for the technology to clear a peer review stage before releasing details, the app is essentially a simulator that allows scientists to enter their warp-speed equations to validate whether they’re practical.

“When somebody publishes a warp metric for the first time, people say, ‘Okay, is your metric physical?’” Martire says. The answer to that question—whether the metric has practical potential or is strictly theoretical—is hard to establish given the challenges of testing these hypotheses. That determination could take six to eight months. “Now we can tell you within seconds, and it shows you visually how off you are or how close you are,” he says.

While useful, the app will speed up the preliminary math only for future researchers. Galaxy-sized challenges remain before we ever experience turbocharged interstellar travel. Alcubierre worries in particular about what may happen near the walls of the warp bubble. The distortion of space is so violent there, he notes, that it would destroy anything that gets close. “If you collide with something on your path, it would almost certainly be catastrophic,” he says.

Natário mulls even more practical issues, like steering and stopping. “It’s a bubble of space, that you’re pushing through space,” he says. “So, you’d have to tell space ... to curve in front of your spaceship.” But therein lies the problem: You can’t signal to the space in front of you to behave the way you want it to.

His opinion? Superluminal travel is impossible. “You need these huge deformations that we have no idea how to accomplish,” Natário says. “So yes, there has been a lot of effort toward this and studying these weird solutions, but this is all still completely theoretical, abstract, and very, very, very, very far from getting anywhere near a practical warp drive.” That’s “very” to the power of four, mind you—each crushing blow pushing us exponentially, excruciatingly further and further away from our yearned-for superluminal lives.

Ultimately, the pursuit of viable high-speed interstellar transportation also points to a more pressing terrestrial challenge: how the scientific community tackles ultra-long-term challenges in the first place. Most of the research so far has come from self-starters without direct funding, or by serendipitous discoveries made while exploring often unrelated research, such as Dr. White’s work on Casimir cavities.

Many scientists argue that we’re in a multi-decade period of stagnation in physics research, and warp drive—despite its epic time horizons before initial research leads to galaxy-spanning adventures—is somewhat emblematic of that stagnation. Sabine Hossenfelder, a research fellow at the Frankfurt Institute for Advanced Studies and creator of the YouTube channel Science Without the Gobbledygook , noted in a 2020 blog post that physics research has drifted away from frequent, persistent physical experimentation to exorbitant infusions of cash into relatively few devices. She writes that with fewer experiments, serendipitous discoveries become increasingly unlikely. Without those discoveries, the technological progress needed to keep experiments economically viable never materializes.

When asked whether this applied equally to warp drive, Hossenfelder sees a faint but plausible connection. “Warp drives are an idea that is not going to lead to applications in the next 1,000 years or so,” she says. “So they don’t play a big role in that one way to another. But when it comes to the funding, you see some overlap in the problems.”

So, despite all the advances, the horizon for a warp drive remains achingly remote. That hasn’t fazed the scientists involved, though. A few years ago, while teaching in France, White visited the Strasbourg Cathedral with his wife. While admiring its 466-foot-tall spire, he was struck by the fact that construction began in 1015 but didn’t wrap up until 1439—a span of 424 years. Those who built the basement had no chance of ever seeing the finished product, but they knew they had to do their part to aid future generations. “I don’t have a crystal ball,” White says. “I don’t know what the future holds. But I know what I need to be doing right now.”

Eric Adams is a writer and photographer who focuses on technology, transportation, science, travel, and other subjects for a wide range of outlets, including Wired, The Drive, Gear Patrol, Men's Health, Popular Science, Forbes, and others.

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Warp Drive May Be More Feasible Than Thought, Scientists Say

HOUSTON — A warp drive to achieve faster-than-light travel — a concept popularized in television's Star Trek — may not be as unrealistic as once thought, scientists say.

A warp drive would manipulate space-time itself to move a starship, taking advantage of a loophole in the laws of physics that prevent anything from moving faster than light . A concept for a real-life warp drive was suggested in 1994 by Mexican physicist Miguel Alcubierre; however, subsequent calculations found that such a device would require prohibitive amounts of energy.

Now physicists say that adjustments can be made to the proposed warp drive that would enable it to run on significantly less energy, potentially bringing the idea back from the realm of science fiction into science.

"There is hope," Harold "Sonny" White of NASA's Johnson Space Center said here Friday (Sept. 14) at the 100 Year Starship Symposium , a meeting to discuss the challenges of interstellar spaceflight.

Warping space-time

An Alcubierre warp drive would involve a football-shape spacecraft attached to a large ring encircling it. This ring, potentially made of exotic matter, would cause space-time to warp around the starship, creating a region of contracted space in front of it and expanded space behind. [ Star Trek's Warp Drive: Are We There Yet? | Video ]

Meanwhile, the starship itself would stay inside a bubble of flat space-time that wasn't being warped at all.

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"Everything within space is restricted by the speed of light," explained Richard Obousy, president of Icarus Interstellar, a non-profit group of scientists and engineers devoted to pursuing interstellar spaceflight. "But the really cool thing is space-time, the fabric of space, is not limited by the speed of light."

With this concept, the spacecraft would be able to achieve an effective speed of about 10 times the speed of light, all without breaking the cosmic speed limit.

The only problem is, previous studies estimated the warp drive would require a minimum amount of energy about equal to the mass-energy of the planet Jupiter.

But recently White calculated what would happen if the shape of the ring encircling the spacecraft was adjusted into more of a rounded donut, as opposed to a flat ring. He found in that case, the warp drive could be powered by a mass about the size of a spacecraft like the Voyager 1 probe NASA launched in 1977.

Furthermore, if the intensity of the space warps can be oscillated over time, the energy required is reduced even more, White found.

"The findings I presented today change it from impractical to plausible and worth further investigation," White told SPACE.com. "The additional energy reduction realized by oscillating the bubble intensity is an interesting conjecture that we will enjoy looking at in the lab."

Laboratory tests

White and his colleagues have begun experimenting with a mini version of the warp drive in their laboratory.

They set up what they call the White-Juday Warp Field Interferometer at the Johnson Space Center, essentially creating a laser interferometer that instigates micro versions of space-time warps.

"We're trying to see if we can generate a very tiny instance of this in a tabletop experiment, to try to perturb space-time by one part in 10 million," White said.

He called the project a "humble experiment" compared to what would be needed for a real warp drive, but said it represents a promising first step.

And other scientists stressed that even outlandish-sounding ideas, such as the warp drive, need to be considered if humanity is serious about traveling to other stars.

"If we're ever going to become a true spacefaring civilization, we're going to have to think outside the box a little bit, we're going to have to be a little bit audacious," Obousy said.

You can follow SPACE.com assistant managing editor Clara Moskowitz on Twitter @ClaraMoskowitz .   Follow SPACE.com on Twitter  @Spacedotcom . We're also on Facebook  &  Google+ .

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: [email protected].

Clara Moskowitz is a science and space writer who joined the Space.com team in 2008 and served as Assistant Managing Editor from 2011 to 2013. Clara has a bachelor's degree in astronomy and physics from Wesleyan University, and a graduate certificate in science writing from the University of California, Santa Cruz. She covers everything from astronomy to human spaceflight and once aced a NASTAR suborbital spaceflight training program for space missions. Clara is currently Associate Editor of Scientific American. To see her latest project is, follow Clara on Twitter.

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11 min read

Star Trek ’s Warp Drive Leads to New Physics

Researchers are taking a closer look at this science-fiction staple—and bringing the idea a little closer to reality

By Robert Gast & Spektrum

Warp one, engage!

Getty Images

For Erik Lentz, it all started with Star Trek . Every few episodes of Star Trek: The Next Generation, Captain Jean-Luc Picard would raise his hand and order, “Warp one, engage!” Then stars became dashes, and light-years flashed by at impossible speed. And Lentz, still in elementary school, wondered whether warp drive might also work in real life.

“At some point, I realized that the technology didn’t exist,” Lentz says. He studied physics at the University of Washington, wrote his Ph.D. dissertation on dark matter and generally became far too busy to be concerned with science fiction. But then, at the start of the coronavirus pandemic, Lentz found himself alone in Göttingen, Germany, where he was doing postdoctoral work. He suddenly had plenty of free time on his hands—and childhood fancies in his head.

Lentz read everything he could find on warp drives in the scientific literature, which was not very much. Then he began to think about it for himself. After a few weeks, something occurred to him that everyone else seemed to have overlooked. Lentz put his idea on paper and discussed it with more experienced colleagues. A year later it was published in a physics journal .

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It quickly became clear that Lentz was not the only person dreaming about warp drives. Media outlets all over the world picked up the story , and a dozen journalists asked for interviews. A discussion on the online forum Reddit attracted 2,700 comments and 33,000 likes. One Internet user wrote, “Anyone else feel like they were born 300 years too soon?”

A Bubble in Space and Time

There is no doubt that the universe is still far too vast for humans to traverse. It takes more than four years for a beam of light to reach Earth’s nearest star Proxima Centauri. Even with the best available propulsion systems, it would take tens of thousands of years for a human to get there. One can always dream about establishing colonies in other star systems, but it is not a journey anyone is likely to undertake.

But perhaps one day it might be possible to reduce the travel time. There are many ideas about how to do that, from laser-accelerated solar sails to nuclear propulsion. But even with the aid of these technologies, you would not get too far in a human lifetime. The galaxy really is open only to those who travel as fast as light—or faster.

NASA artist’s 1998 rendition of warp drive travel. The ring around the spacecraft generates a negative-energy field. From today’s perspective, the negative-energy field would no longer be necessary. Credit:  NASA; Digital art by Les Bossinas (Cortez III Service Corp)

For that very reason, imaginative physicists have long been pondering the ultimate propulsion system: a bubble in space and time in which a spaceship could dash from sun to sun, just like the USS Enterprise did. This is research at the fringe of science: not necessarily wrong but spiced with a large pinch of optimism.

The fact that scientists are dealing with the idea at all today is thanks to a 1994 paper by Mexican theoretical physicist Miguel Alcubierre. At the time, Alcubierre was not just a passionate Star Trek devotee. In his doctoral thesis at the University of Wales College Cardiff (now Cardiff University), Alcubierre also worked on the theory of relativity. Strictly speaking, the theory states that nothing can travel faster than light. But by applying a little creativity, Alcubierre identified an apparent loophole.

For physicists, Albert Einstein’s theory of relativity consists of two parts: The “special” theory of relativity, which dates from 1905, deals with the uniform motion of fast-as-light objects. Ten years later Einstein generalized these ideas for accelerating bodies. According to “general” relativity, the three spatial dimensions we are familiar with (up-down, left-right, front-back) are inseparable from time. Every mass deforms this spacetime.

According to Albert Einstein’s epic discovery, we live in four-dimensional “spacetime.” Spacetime is not static. Like a tablecloth, it is deformed by massive objects. Everything that moves across the tablecloth (or through spacetime) can accelerate only up to the speed limit set by light. The tablecloth itself, on the other hand, can be deformed at any speed, as the universe itself shows in some situations.

At the instant of the big bang, for example, the original spacetime structure presumably expanded for a split second and did so much faster than any ray of light could travel. Even today, the expansion continues to drive extremely distant galaxies away at speeds faster than light, which means their light can no longer reach us.

Based on his discovery, Alcubierre surmised that it would only be a small step to a warp drive. If spacetime were contracted in front of a spaceship and expanded behind it to compensate, it would be possible to travel to one’s destination at a speed faster than light. The ship would remain encapsulated in a bubble, and the crew would not sense the magnitude of the interstellar journey. In a 2017 lecture, Alcubierre compared it to being on a passenger conveyor belt at the airport: “You can imagine that the floor behind you is being created out of nothing and in front of you it is being destroyed, so you move along.”

But formulating this idea in the language of general relativity immediately gives rise to major practical problems. First, to deform spacetime so radically, you would need to cram a huge mass into a bubble bounded by a wall thinner than an atomic nucleus. Then you would need two forms of matter to maintain the bubble. The gravity of ordinary mass would cause the space at the front of the bubble to contract, moving the whole structure forward. But at the same time, the space at the back of the bubble would need to expand like rising bread dough. To make that expansion happen, according to Alcubierre, you would need some form of negative energy radiating a kind of antigravity.

The Curse of Negative Energy

For most physicists, that was the end of the thought experiment. Energy—which according to Einstein’s formula E = mc2 is equivalent to unconstrained mass—seems like it must, by definition, be positive. But according to quantum theory, it can indeed have a negative value. This seems to occur only in rare special cases, however—on a tiny scale. In the so-called Casimir effect , for example, the quantities involved are so minuscule that any technological application seems absurd.

Alcubierre, now a professor of physics at the National Autonomous University of Mexico, concedes this point. In terms of a potential technology, warp drives “are greatly lacking,” he and one of his colleagues wrote in a recent preprint paper . He has now turned his attention to known phenomena, such as black holes. The warp drive concept, however, retains its fascination, especially for Trekkies—and for a few gravitational physicists, who occasionally publish variations on the idea.

Some of these papers have shown how to reduce the bubble’s mass requirements so that the total mass needed to deform spacetime would be less than that of our sun. But no one was able to get around the problem of negative energy—until Lentz took it up during the lockdown in Göttingen. In his enforced isolation, Lentz found a way to construct a warp bubble using only positive energy. In so doing, he may have overcome the greatest objection to warp drives.

What made it possible was a special feature of the geometry of spacetime that Lentz discovered buried in the general theory of relativity—more precisely, in Einstein’s field equations. These equations can calculate how a particular distribution of matter and energy deforms spacetime. Researchers can also use them, as Alcubierre did, to determine the mass and energy needed to produce a specific curvature of space.

Dealing with a dynamic, four-dimensional structure like spacetime is extremely complicated, however. Writing out Einstein’s formulas in full produces a jumble of nested differential equations with thousands of terms. Depending on the assumptions you make about a particular physical situation, you only take some of those terms into account. For theorists, it is an almost limitless playground.

Principle of the Alcubierre drive: Spacetime contracts at the front of the bubble (right), corresponding to a warp in spacetime. Behind the bubble (left), new space is created out of nothing, which is equivalent to stretching spacetime. Credit: AllenMcC Wikimedia  (CC BY-SA 3.0)

Lentz specifically examined the assumptions leading to the negative energy requirements in Alcubierre’s work. Like his colleague, Lentz began by analyzing spacetime, modeling the multidimensional substance as a stack of very thin layers. He found that Alcubierre had only considered comparatively simple “linear” relationships between the equations for shifting one layer onto the next. At this point, choosing more complex “hyperbolic” relations, which typically express rapidly changing quantities, results in a different warp bubble than the one obtained by Alcubierre. It still requires enormous amounts of mass and energy but, according to Lentz’s calculations, only positive amounts. “I was very surprised that no one had tried this before me,” Lentz says.

Lentz’s bubble looks different from the one Alcubierre worked out in 1994. It consists of diamond-shaped regions of altered spacetime that resemble a flock of birds. Creating such a spacetime geometry in reality would involve a complicated layering of rings and disks, not made of solid material but of an extremely dense fluid of charged particles, similar to the substance found in the interior of neutron stars, Lentz says.

That means near-light-speed travel is still very, very far away from applied technology. But now that no exotic negative energy densities are needed—at least according to Lentz’s latest work—the theoretical games are within the realm of established physics. Alcubierre describes Lentz’s paper as a “very important development.” Francisco Lobo, a researcher at the University of Lisbon and a colleague of Alcubierre’s, who has published a textbook on warp drives, cannot find any obvious errors either. “If correct, this has the potential of opening up new interest and novel avenues of research in warp drive physics,” he says.

Lentz’s idea has even aroused interest among researchers outside the small community of warp drive enthusiasts, including Lavinia Heisenberg, a professor of cosmology at the Swiss Federal Institute of Technology Zurich. Heisenberg and her student Shaun Fell found Lentz’s paper so exciting that they built on it by designing their own positive-energy warp bubbles that would require as little as a thousandth of the mass of our sun.

“The whole thing is much less mysterious than most people assume,” says Alexey Bobrick , an astrophysicist at Lund University in Sweden. Collaborating with New York City–based entrepreneur Gianni Martire, Bobrick came up with some promising solutions to Einstein’s field equations in 2020. According to Bobrick, all that is needed for a warp bubble is an appropriately shaped shell made of dense material that bends spacetime in its immediate vicinity while the universe through which the bubble moves and the space within the shell remain comparatively undisturbed.

Time Goes by So Slowly

“Comparatively” is the key. Alcubierre and later warp architects assumed an abrupt transition between the contorted spacetime in the wall of the bubble and the smooth interior and exterior. But Bobrick and Martire found this “truncation” of the gravitational field to be the reason why large amounts of negative energy are required to stabilize the contortion of space and time.

Abandoning the cartoonish image of a soap bubble, however, makes it possible to build warp drives based on ordinary matter, they claim. The gravitational field would not simply disappear when one moved away from the wall of the shell. Instead it would gradually decay. Spacetime would therefore also be curved inside the bubble. To travelers in a spaceship right in the middle of the bubble, this phenomenon would be most obvious in the passage of time: their watches would go slower than in the rest of space because, according to the theory of relativity, time is affected by gravity.

The slower passage of time on a spaceship might be something interstellar travelers appreciate. Still, Bobrick and Martire describe other obstacles. So far, they argue, there is no known way to actually accelerate a warp bubble. All previous ideas about the subject simply assume that the curvature of spacetime is already moving at high speed.

A beam of light travels 299,000 kilometers per second. According to Einstein’s special theory of relativity, this is a physical constant. The speed of light is the maximum speed any particle may reach, and a particle can only do so if it has no mass. Consequently, today’s physics offers no possibility of accelerating objects beyond the speed of light. On closer inspection, however, this limit only applies within the four-dimensional spacetime comprising the universe. Outside of that, even greater speeds appear to be possible.

“None of the physically conceivable warp drives can accelerate to speeds faster than light,” Bobrick says. That is because you would require matter capable of being ejected at speeds faster than light—but no known particles can travel that fast. Furthermore, the bubble could not be controlled by occupants of the spaceship itself because they would lose contact with the outside world, owing to the extremely strong curvature of space around them.

Lentz sees these objections as a problem, too, but he believes a solution can be found. Bobrick, meanwhile, points out that it is also possible to travel to distant stars at a third or half the speed of light, especially if time passes more slowly for the people in the warp bubble. Just do not think about the fact that all your relatives left behind on Earth will probably have died of old age before you get back. “But at least the idea is no longer completely crazy,” Bobrick says.

From Theory to Practice

There is still some debate about whether warp bubbles really can do without negative energy. Recently, three theoreticians suggested that this claim was only true for observers moving next to the bubble. Plus, not everything that seems possible according to the theory of relativity actually exists—or is technologically feasible. For example, Einstein’s field equations can also be used to justify “white” holes (the antithesis of their black hole counterparts), Einstein-Rosen bridges (frequently called wormholes) and other exotic alterations in spacetime that no one has ever observed. That could be because laws of nature, as yet unknown, preclude such phenomena.

Some researchers therefore caution against going overboard with the fantasies. Space propulsion expert Martin Tajmar of the Technical University of Dresden, for example, sees no practical relevance for the current work on warp drives. The huge masses involved simply exceed anything that can be tested on Earth, he says.

Most veteran warp drive researchers would undoubtedly agree. They see their work less as preparation for real-world experiments and more as a way of exploring the limits of relativity. In this endeavor, even speculative “thought experiments” are useful, Lobo says.

Lentz, on the other hand, is actively working toward a practical application of his idea. After his research in Göttingen, he took a job at an IT company. But in his spare time, he still thinks about how to accelerate a bend in spacetime to speeds faster than light and how to reduce the energy required to do so.

Lentz also advocates looking closely at the surroundings of neutron stars. It could be that these ultracompact stellar remnants eject bubbles like those that he describes in his paper. “As long as one doesn’t let personal biases get in the way and accepts what evidence tells you, it’s a field of research that is as worthy of being pursued as any other,” he says.

Jean-Luc Picard would probably see it similarly. “Things are only impossible until they are not,” the character noted in an episode of Star Trek: The Next Generation . But that’s also easier to say when you live 300 years in the future.

This article originally appeared in Spektrum der Wissenschaft and was reproduced with permission

April 23, 2014

Warp Drive Research Key to Interstellar Travel

As any avid Star Trek fan can tell you, the eccentric physicist Zefram Cochrane invented the warp-drive engine in the year 2063. It wasn't easy.

By Mark Alpert

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American

As any avid Star Trek fan can tell you, the eccentric physicist Zefram Cochrane invented the warp-drive engine in the year 2063. It wasn’t easy. Cochrane had to contend with evil time-traveling aliens who were determined to stop him from building the faster-than-light propulsion system (see the 1996 movie Star Trek: First Contact for details). But in the end he succeeded, and centuries later his warp drive powered the interstellar voyages of the starship Enterprise.

What Star Trek fans may not know is that a physicist in the real world—specifically, at NASA’s Johnson Space Center in Houston—is investigating the feasibility of building a real warp-drive engine. Harold “Sonny” White, head of the center’s advanced propulsion program, has assembled a tabletop experiment designed to create tiny distortions in spacetime, the malleable fabric of the universe. If the experiment is successful, it may eventually lead to the development of a system that could generate a bubble of warped spacetime around a spacecraft. Instead of increasing the craft’s speed, the warp drive would distort the spacetime along its path, allowing it to sidestep the laws of physics that prohibit faster-than-light travel. Such a spacecraft could cross the vast distances between stars in just a matter of weeks.

For readers and writers of science fiction, this is extraordinary news. It doesn’t really matter that other physicists scoff at White’s idea, arguing that it’s impossible to alter spacetime in this way. Nor does it matter that NASA has allocated only $50,000, a mere smidgeon of the space agency’s $18 billion budget, to the warp-drive research. What makes White’s project so exciting is the immensity of the challenge. It’s heartening to know that even in this era of fiscal belt-tightening, the federal government is willing to place a small bet on the big dream of interstellar travel.

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A surprising number of scientists, engineers and amateur space enthusiasts fervently believe in this dream. They’ve shared their hopes and hypotheses at academic conferences. They’ve founded organizations—the 100 Year Starship project , the Tau Zero Foundation , Icarus Interstellar —that seek to lay the groundwork for an unmanned interstellar mission that could be launched by the end of the century. Their ardor has grown in recent years as astronomers have detected a slew of Earthlike planets orbiting stars that are relatively near our sun. A few dozen of these worlds occupy the so-called “Goldilocks zone” around their stars—they’re neither too hot nor too cold to support life. If further observations confirm the existence of a habitable, idyllic planet in our corner of the galaxy, how could we resist sending an interstellar probe to explore this strange new world?

The problem is getting the spacecraft there in a reasonable amount of time. Believe it or not, NASA already has a probe that’s crossing the space between stars: Voyager 1 , the plucky 1,600-pound craft launched in 1977 to investigate Jupiter, Saturn and their moons. After completing its primary mission the probe zipped past the outer planets, and in 2012 it left the solar system and entered interstellar space. Voyager has traveled almost 12 billion miles since its launch and is now zooming away from us at 38,610 miles per hour. But even at that blistering speed it would take at least 70,000 years to reach any of the nearby stars that might harbor habitable planets. Researchers need to make some serious breakthroughs in spacecraft propulsion to get there faster.

Although White and a few other scientists are tantalized by the possibility of warp drive, most of the interstellar enthusiasts have focused their attention on technologies that are less hypothetical. Icarus Interstellar, for example, is coordinating a study of a proposed mission that would use fusion power—the energy produced by slamming atomic nuclei together—to propel the spacecraft. Nuclear fusion is what gives the hydrogen bomb its bang, and if the energy is properly controlled and harnessed it could accelerate a probe to phenomenal speeds, thousands of times faster than Voyager 1. But researchers have been trying to build a fusion power plant for the past fifty years without much success. The technology hasn’t proved itself on Earth yet, and it’s certainly not ready to be installed in a spacecraft.

Another big problem is interstellar dust. Although the dust grains in deep space are microscopic, they’ll cause plenty of damage to a probe that’s barreling into them at millions of miles per hour. The spacecraft would have to be equipped with heavy shielding, which would increase the amount of fuel needed to accelerate the craft. And then there’s the need to decelerate the probe before it reaches its destination. There’s no point in sending a spacecraft on a hundred-year journey to a nearby star if it’s going to whiz right past the star’s habitable planets. During the later stages of its voyage the probe would have to turn its engines around and fire them in the opposite direction to slow itself down. But then the spacecraft would need to carry an even heavier load of fuel.

The complications seem as endless as space itself. The tremendous difficulty of interstellar flight may help explain the famous paradox first noted by physicist Enrico Fermi in 1950: if intelligent life is common in the universe, where are all the aliens? Perhaps extraterrestrials have never visited Earth because it’s just too hard to get here.

Nevertheless, the dream of interstellar travel remains stubbornly alive. Last September the 100 Year Starship project held a symposium on the topic just a month after Icarus Interstellar hosted its own conference. At a time when NASA is struggling to fund all its priorities —building a new launch system for its astronauts, sending new probes to Mars—planning for an interstellar mission may seem absurdly premature. But advocates such as Jill Tarter, who pioneered the effort to hunt for radio signals from extraterrestrial civilizations, argue that exploring other star systems is essential to humanity’s long-term survival. As long as the human race is confined to Earth we’re at high risk of extinction from a planetary catastrophe—a nuclear war, a pandemic, an asteroid impact and so on. The only other world in our solar system that comes even close to being habitable is Mars, and it would take hundreds of years of climate engineering to make the Red Planet livable for humans.

So the ultimate fate of our species may lie among the stars. Perhaps in a thousand years or so our civilization will look something like Star Trek’s United Federation of Planets. To reach that point, though, we need to adopt the motto of the starship Enterprise. We have “to boldly go where no man has gone before.”

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Warp Drives and Negative Energy: Physicists Give Chances of Faster-Than-Light Space Travel a Boost

By Mario Borunda, Oklahoma State University May 16, 2021

Faster than light travel is the only way humans could ever get to other stars in a reasonable amount of time. Credit: NASA

The closest star to Earth is Proxima Centauri. It is about 4.25 light-years away, or about 25 trillion miles (40 trillion km). The fastest ever spacecraft, the now-in-space Parker Solar Probe will reach a top speed of 450,000 mph (201 km/s). It would take just 20 seconds to go from Los Angeles to New York City at that speed, but it would take the solar probe about 6,633 years to reach Earth’s nearest neighboring solar system.

If humanity ever wants to travel easily between stars, people will need to go faster than light. But so far, faster-than-light travel is possible only in science fiction.

In Issac Asimov’s Foundation series, humanity can travel from planet to planet, star to star or across the universe using jump drives. As a kid, I read as many of those stories as I could get my hands on. I am now a theoretical physicist and study nanotechnology, but I am still fascinated by the ways humanity could one day travel in space.

Some characters – like the astronauts in the movies “Interstellar” and “Thor” – use wormholes to travel between solar systems in seconds. Another approach – familiar to “Star Trek” fans – is warp drive technology. Warp drives are theoretically possible if still far-fetched technology. Two recent papers made headlines in March when researchers claimed to have overcome one of the many challenges that stand between the theory of warp drives and reality.

But how do these theoretical warp drives really work? And will humans be making the jump to warp speed anytime soon?

This 2-dimensional representation shows the flat, unwarped bubble of spacetime in the center where a warp drive would sit surrounded by compressed spacetime to the right (downward curve) and expanded spacetime to the left (upward curve). Credit: AllenMcC/Wikimedia Commons

Compression and expansion

Physicists’ current understanding of spacetime comes from Albert Einstein’s theory of General Relativity. General Relativity states that space and time are fused and that nothing can travel faster than the speed of light. General relativity also describes how mass and energy warp spacetime – hefty objects like stars and black holes curve spacetime around them. This curvature is what you feel as gravity and why many spacefaring heroes worry about “getting stuck in” or “falling into” a gravity well. Early science fiction writers John Campbell and Asimov saw this warping as a way to skirt the speed limit.

What if a starship could compress space in front of it while expanding spacetime behind it? “Star Trek” took this idea and named it the warp drive.

In 1994, Miguel Alcubierre, a Mexican theoretical physicist, showed that compressing spacetime in front of the spaceship while expanding it behind was mathematically possible within the laws of General Relativity . So, what does that mean? Imagine the distance between two points is 10 meters (33 feet). If you are standing at point A and can travel one meter per second, it would take 10 seconds to get to point B. However, let’s say you could somehow compress the space between you and point B so that the interval is now just one meter. Then, moving through spacetime at your maximum speed of one meter per second, you would be able to reach point B in about one second. In theory, this approach does not contradict the laws of relativity since you are not moving faster than light in the space around you. Alcubierre showed that the warp drive from “Star Trek” was in fact theoretically possible.

Proxima Centauri here we come, right? Unfortunately, Alcubierre’s method of compressing spacetime had one problem: it requires negative energy or negative mass.

This 2–dimensional representation shows how positive mass curves spacetime (left side, blue earth) and negative mass curves spacetime in an opposite direction (right side, red earth). Credit: Tokamac/Wikimedia Commons, CC BY-SA

A negative energy problem

Alcubierre’s warp drive would work by creating a bubble of flat spacetime around the spaceship and curving spacetime around that bubble to reduce distances. The warp drive would require either negative mass – a theorized type of matter – or a ring of negative energy density to work. Physicists have never observed negative mass, so that leaves negative energy as the only option.

To create negative energy, a warp drive would use a huge amount of mass to create an imbalance between particles and antiparticles. For example, if an electron and an antielectron appear near the warp drive, one of the particles would get trapped by the mass and this results in an imbalance. This imbalance results in negative energy density. Alcubierre’s warp drive would use this negative energy to create the spacetime bubble.

But for a warp drive to generate enough negative energy, you would need a lot of matter. Alcubierre estimated that a warp drive with a 100-meter bubble would require the mass of the entire visible universe .

In 1999, physicist Chris Van Den Broeck showed that expanding the volume inside the bubble but keeping the surface area constant would reduce the energy requirements significantly , to just about the mass of the sun. A significant improvement, but still far beyond all practical possibilities.

A sci-fi future?

Two recent papers – one by Alexey Bobrick and Gianni Martire and another by Erik Lentz – provide solutions that seem to bring warp drives closer to reality.

Bobrick and Martire realized that by modifying spacetime within the bubble in a certain way, they could remove the need to use negative energy. This solution, though, does not produce a warp drive that can go faster than light.

Independently, Lentz also proposed a solution that does not require negative energy. He used a different geometric approach to solve the equations of General Relativity, and by doing so, he found that a warp drive wouldn’t need to use negative energy. Lentz’s solution would allow the bubble to travel faster than the speed of light.

It is essential to point out that these exciting developments are mathematical models. As a physicist, I won’t fully trust models until we have experimental proof. Yet, the science of warp drives is coming into view. As a science fiction fan, I welcome all this innovative thinking. In the words of Captain Picard , things are only impossible until they are not.

Written by Mario Borunda, Associate Professor of Physics, Oklahoma State University.

Adapted from an article originally published on The Conversation .

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The battle of the covid variants: a winning approach, 27 comments on "warp drives and negative energy: physicists give chances of faster-than-light space travel a boost".

Chinese Logicians School and their paradoxes aside for the time being: Even though it’s white, has wings and it’s name is Pegasus, it’s still a horse. It cannot fly and is as dead as the Mythology that spawned it. A dead horse is not a horse. Beat it all you want, it’s a deadhorse. Subtle Logic. Essentials and Essential Quality (Whiteness and Horse-ness) define a beast of a different color. Light is not a speed limit if everything is moving at the speed of light. It is more like a bullet fired off the trailing end of a speeding train. You can’t see it until it hits something… like your retina. The problem begins in the occipital lobe and migrates frontally. From there, it is only a matter of TIME… and the MANIFOLD UNIVERSE of the MIND: IT is all in how one looks at it.

Now… Back to the telescope and a cup of hot chocolate. Here’s looking at you. ☝️

Wow, that’s some deep brown matter, Alex, and I don’t mean the coffee.

Well… We ARE immersed in a wealth of brown matter. Orthodoxy notwithstanding, one can science the heck out of it, but it is a meaningless WASTE of human resources when misdirected: particularly when it is EXPENSIVE. It’s in the GREY MATTER, ultimately, the biases that allow us to poison our “home” planet on the promise of finding another one JUST LIKE IT. Good luck with that: not in a hundred lifetimes, even @ the speed o’ lite. To wit: Whatever we might aim our Lightships at, ISN’T THERE ANYMORE. WARP NINE, MUSTER WARF. MAKE IT SO. LOL What I was suggesting was a paradigm (that word) SHIFT. Ya know, like… maybe stand still, RELATIVELY SPEAKING, while Space moves past us. Forget about TIME for the time being. There is no way “around” it, but maybe there is a way outside of it. Some theorists are pursuing this line of reasoning. I have been “educated” to an insight: The solution is much simpler than our Science can imagine; as vested as it is in misconceptions about this ONE Universe, that belong in the Middle (muddle?) Ages, along with witches, goblins, the homunculus, god, seven days in the week and a paradigm of EXISTENCE hopelessly mired in its obsession with mortality and bodily functions; which is still trying to turn lead into gold, but fails at differentiating SH*T FROM SHINOLA. Call me IDEALISTIC… and I will correct your thinking. REALISTICALLY speaking, Pangloss, I GUESS was correct: We live in the BEST if all possible WORLDS…I have some land in Florida for sale. Real cheap. It only under water twice a day.

It’s not brain surgery.

BTW, I was drinking hot chocolate; a suggestion of a neurosurgeon friend who drinks it during prolonged surgeries (+6 hours). It contains a better form of caffeine than coffee; one that does not rattle the nerves. With the “work” he does, one little tremor and ZIP! there goes your memory of Aunt Tilly, or maybe just the memory of how to tie your own shoelaces…

👽 Keep looking up. ☝️

Why did you take out my comment on Dr. Lee and Synthetic Gravity demonstrated in Huntsville, Alabama in 1998? I realize the program went black, i.e., Beyond Top Secret and thus was scrubbed from the Internet by the year 2000.

Quantum information travels faster than light, so that is what everyone else in the universe exploits to travel to the stars. Quantum Tunneling Vehicles (QTV). They emulate an elementary particle by spinning a strong electric or magnetic field around a superconducting hull to engage a particle spreadsheet function. Altering and renormalizing the spin of the field should cause the universe to re-locate the ersatz particle. It’s a form of quantum teleportation, if you mess with the constancy of the spin field, you can trick the universe into changing it’s location. Electric tunneling vehicles would be oblate spheroids, magnetic tunneling vehicles would be cigar shaped. Classic UFO’s, saucers and cigars. Why don’t we just follow their lead? Or are we stupid cavemen who need rockets to fly through space? Classical physics has a speed limit, the speed of light. If you want to beat it safely, you have to play the quantum game instead. Fortunately, quantum information travels faster than light. Quantum laws govern the conservation laws, which are monitored on every particle in the universe at once. So if I can con the universe into thinking my ship is an elementary particle and that my “particle” belongs somewhere else, I’ll instantly find my “particle” there. The quantum machinery of reality is not subject to the limitations of the classical laws it emulates. The closest stars may be only hours or minutes away to a sophisticated Quantum Tunneling Vehicle. And if you need a lift vehicle that can hit orbit 20 rimes a day with no pollution, or go to Mars in minutes, all we need are room temperature superconductors and a lot of electricity.

You have something there. Generating a strong enough field will effectively create a “bubble” around which Time and Space will flow…at the Speed of light and beyond, as the “vector” of “flight” shortens in response to Space/Time distortion… Only a Theory. But it beats the Wile E. Coyote, strap a rocket to your ass, school of space travel. As in any Scientific theorising, the first SPACE one needs to overcome is the space between one’s ears. It is, after all, the Final Frontier.

Babu G. Ranganathan* (B.A. Bible/Biology)

JUST BECAUSE SCIENCE CAN EXPLAIN how an airplane works doesn’t mean that no one designed or made the airplane. And just because science can explain how life or the universe works doesn’t mean there was no Designer and Maker behind them.

Natural laws may explain how the order in the universe works and operates, but mere undirected natural laws cannot explain the origin of that order. Once you have a complete and living cell then the genetic code and biological machinery exist to direct the formation of more cells from raw materials such as amino acids and other chemicals, but how could life or the cell have naturally originated when no directing code and mechanisms existed in nature? Read my Internet article: HOW FORENSIC SCIENCE REFUTES ATHEISM.

WHAT IS SCIENCE? Science simply is knowledge based on observation. No human observed the universe coming by chance or by design, by creation or by evolution. These are positions of faith. The issue is which faith the scientific evidence best supports.

SCIENCE SHOWS THAT THE UNIVERSE CANNOT BE ETERNAL because it could not have sustained itself eternally due to the law of entropy (increasing and irreversible net energy decay, even in an open system). Even a hypothetical oscillating universe could not continue to oscillate eternally! Einstein’s General Theory of Relativity shows that space, matter, and time all are physical and all had a beginning. Space even produces particles because it’s actually something, not nothing. What about the Higgs boson (the so-called “God Particle”)? The Higgs boson, even if it existed, would not have created mass from nothing, but rather it would have converted energy into mass. Einstein showed that all matter is some form of energy. Even time had a beginning! Time is not eternal.

The law of entropy doesn’t allow the universe to be eternal. If the universe were eternal, everything, including time (which modern science has shown is as physical as mass and space), would have become totally entropied by now and the entire universe would have ended in a uniform heat death a long, long time ago. The fact that this hasn’t happened already is powerful evidence for a beginning to the universe.

Popular atheistic scientist Stephen Hawking admits that the universe had a beginning and came from nothing but he believes that nothing became something by a natural process yet to be discovered. That’s not rational thinking at all, and it also would be making the effect greater than its cause to say that nothing created something. The beginning had to be of supernatural origin because science teaches us from the First Law of Thermodynamics that natural laws and processes do not have the ability to bring something into existence from nothing.

The supernatural origin of the universe cannot be proved by science but science points to a supernatural intelligence and power for the origin and order of the universe. Where did God come from? Obviously, unlike the universe, God’s nature doesn’t require a beginning.

The disorder in the universe can be explained because of chance and random processes, but the order can be explained only because of intelligence and design.

Gravity may explain how the order found in the precise and orderly courses of thousands of billions of stars is maintained, but gravity cannot explain the origin of that order.

Some evolutionary astronomers believe that trillions of stars crashed into each other leaving surviving stars to find precise orderly orbits in space. Not only is this irrational, but if there was such a mass collision of stars then there would be a super mass residue of gas clouds in space to support this hypothesis. The present level of residue of gas clouds in space doesn’t support the magnitude of star deaths required for such a hypothesis. And, as already stated, the origin of stars cannot be explained by the Big Bang because of the reasons mentioned above. It’s one thing to say that stars may decay and die into random gas clouds, but it is totally different to say that gas clouds form into stars.

Even the father of Chaos theory admitted that the “mechanisms” existing in the non-living world allow for only very rudimentary levels of order to arise spontaneously (by chance), but not the kind or level of order we find in the structures of DNA, RNA, and proteins. Yes, individual amino acids have been shown to come into existence by chance but not protein molecules which require that the various amino acids be in a precise sequence just like the letters found in a sentence.

Some things don’t need experiment or scientific proof. In law there is a dictum called prima facie evidence. It means “evidence that speaks for itself.”

An example of a true prima facie would be if you discovered an elaborate sand castle on the beach. You don’t have to experiment to know that it came by design and not by the chance forces of wind and water.

If you discovered a romantic letter or message written in the sand, you don’t have to experiment to know that it was by design and not because a stick randomly carried by wind put it there. You naturally assume that an intelligent and rational being was responsible.

It’s interesting that Carl Sagan would have acknowledged sequential radio signals in space as evidence of intelligent life sending them, but he wouldn’t acknowledge the sequential structure of molecules in DNA (the genetic code) as evidence of an intelligent Cause. Read my popular Internet article, HOW DID MY DNA MAKE ME.

I encourage all to read my popular Internet articles:

NATURAL LIMITS TO EVOLUTION HOW FORENSIC SCIENCE REFUTES ATHEISM

Visit my latest Internet site: THE SCIENCE SUPPORTING CREATION (This site answers many arguments, both old and new, that have been used by evolutionists to support their theory)

Author of popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS

*I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I’ve been privileged to be recognized in the 24th edition of Marquis “Who’s Who in The East” for my writings on religion and science.

Strong is the wind that blows…

We should continue to search, yet it seems to me more effort is and should be placed on inner planetary travel. Nuclear rocket engines or even better fusion drive with impulses reaching 30,000 mps would open the planets and mining of asteroids. This would reduce travel time and fuel consumption making the inner planets give up their secrets and spread out mankind against catastrophe. I would love to travel to proxima centaury in what’s left of my life, it’s not going to happen. That’s why we have science fiction stories!

Warp drives and negative energy…either reduce mass beyond zero or…maybe a large time difference.. bubble with large time difference like helium vs. air…or tuning a radio to a different frequency than the natural surrounding space?

The way that the Star Trek’s warp dive works is that the Antimatter is stored because it needs a smaller area to contain it in a magnetic field. The Nacelles in the front is what collects the matter. They are called Bussard Collector. It then goes to a Dilithium Chamber where the Dilithium Crystals are. The matter and antimatter enters the chamber and instead of a violent explosion the Dilithium controls the explosion and is converted to warp plasma. The plasma then goes back to the nacelle where the Warp Plasma Coils are and creates the warp bubble and then bends the space in front of the ship.

SpaceTime idea seems like a 2D model. Living on Earth is a kind of gravity well that’s why we need massive energy to escape it pull down. I don’t but the ‘spacetime’ idea. Space is relative emptiness. Time is a measure of movement.

Thus far humans have been thinking of REpulsion methods of travel. Pretty much male thinking. But say you want to go towards a female, you can use ‘push’ but most importantly ‘pull’ method; ie: attraction A combination of pull(attraction) and push(repulsion) would work better.

Think of a plant. How does it grow towards the light? It produces a substance that captures and stores light energy and transfers it to the roots to push further into the soil. So a plant has a pull and push method/mechanism (ATP, is it?)

Now you want to go to another star system. Ok. Aim your light-capture device at the stars center mass. Begin light collection, storage and transfer. Expel light thru rear. This method is like using light as zipline. But what material could capture light energy, store and/or transfer it out causing the spacecraft to pull and push itself towards the destination?

Or maybe a light-attracting device in the bow and a light-repelling device in the stern. Lineup the ship between two stars and go. The bow pulls towards the destined/arrival star while the stern pushes off the source/departing star.

Another way or maybe related is a kind of lightplane that sucks in light and expells it (like an airplane). But what kind of engine & fuel would one need to suckin light, ‘combust it and expell it’?

Another idea is to run a ship on cosmic background radiation.

Think of how long it took ‘god’ to build an organism to build a telescope to see light from a distant star. Evolution got us here in about 4.5B years, right? How can we travel at the speed of imagination? We need light. Go towards the light.

1) Attract light and repel light. Photonic propulsiom? 2) Space is a relatively cold void, what cuts thru a cold void? Hot plasma? Plasma Drive? 3) Combination of engines/methods (all-in-one).

We can build and prepare for when our star goes supernova and surf that in all directions. ~4.5B years.

It makes sense that our star’s life cycle and consciousness would follow ours. At midlife, I am beginning to see what is possible and not for me. Sure I still wish and hope with imaginatiom, but time to get real. It follows that since this star made and sustains us that once its gone, so will we be. Unless perhaps if we link up to another star or to the supermassive giant star in our galactic core. And when that goes supernova we can surf that. When a star goes boom, it spreads its matter out. Its amazing enough that the star maintains a balanced fusion reaction, but that it also explodes or dies out as it loses mass. We don’t have to wait. I’m sure we can imagine something and mame it real. I mean can we even excite a particle to go at light speed? And 6k years is still shorter than waiting 4.5 billion years to be shot out like dead matter. I think we need to capture more energy from our star, concentrate it, build brains (organic & inorganic), swarm brains, augment/unify intelligence and consciousness. Maybe there is a way to recombine light coming from another star with light from our star to build particles/matter at the destined end by scanning ourselves from our end. Yes teleportation via 3D printing matter using light from destined star and energy from our star. In 4.5B years I think we can perfect this. (One issue is it might be less dense at the destined end.)

Imagination is the key; the crazier the better.

We might have to figure out a way to take our Earth mothership with us since we are wholly dependent on her ATM. Say within 4.5B years we would have been able to remake all the matter in the solar system into useful devices, basically remaking our planet & ourselves via 3D quantum plank’s length printing. Basically reshape all matter to our imagined consciousness. Priority is to extract more and more energy from our star then we’ll have more possibilities and if we figure out a hack can multiply virally throughout the galaxy increasing our chances. Seems destined and predetermimed. Energy capture & matter manipulation is key. We need sharper senses: better ‘nanoscopes’, better causal-logic processes, finer manipulation of matter, energy efficiency, more accurate theories & mathmatics…anything & everything; there is no limit to godliness.

how long would you say it would take to successfully and completely create said warp drive?

In truth, it took God one day to create the first human being without evolution. It took six days to create the whole Universe. He made us in his image, but not so that we ARE Gods, but his children. He is the God of creation, thus we should be creative, we will find a way to travel faster than the speed of light many times over.

In 2013, A group of us (named C-PLUSS) definitively proved that this proposed method for “warp drive” does not work the way that they say it works. The localised tidal-forces on space-time would be too much to bear. It can cause irreparable damage to local space-time. I have copies of our notes, our conclusions, and our recommendations for an alternative methodology to create a “warp drive”. C-PLUSS stands for the Committee to Propose Legitimate Ultra-luminal Speed Systems. I can be reached at [email protected] .

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Obstacles from interstellar matters and distortion in warp drive superluminal travel scenario

• Regular Article - Theoretical Physics
• Open access
• Published: 02 October 2022
• Volume 82 , article number  861 , ( 2022 )

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• Siyu Bian 1 ,
• Yi Wang 1 , 2 ,
• Zun Wang 1 &
• Mian Zhu   ORCID: orcid.org/0000-0001-9433-2871 1 , 2  

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A preprint version of the article is available at arXiv.

We investigate obstacles of superluminal “warp drive” travels from interactions with interstellar matter and from curvature effects. The effect of collision of interstellar dust particles and photons with the spacecraft will all lead to a pressure proportional to the apparent velocity of the spaceship \(v_s\) . The force exerted on the spacecraft from the curvature effect has two non-trivial components. The radial and longitudinal components scales as \(v_s^2\) and \(v_s^4\) respectively. The above obstacles become increasingly important when the spaceship travels at high superluminal speeds.

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1 Introduction

The warp drive solution [ 1 ] provides a possible way for timelike observers to travel superluminally within the framework of classical General Relativity (GR). In this scenario, the warp bubble, a region of the spacetime deviating from the flat metric, is driven by the local expansion or contraction in its neighboring spacetime. By a proper parameter setting, the propagating speed of the warp bubble can be arbitrarily large, while the internal spacetime of the warp bubble remains quasi-Minkovskian. Hence, the spacecraft inside the warp bubble can travel between two distant points in an arbitrarily short period and remain inside its local lightcones. See [ 2 , 3 , 4 , 5 ] for recent reviews.

There are several theoretical challenges on the warp drive geometry currently. For example: (i) To generate a warp drive spacetime, exotic matters violating the Weak Energy Condition (WEC) and Null Energy Condition (NEC) [ 1 , 6 ] are required. Superluminal travel and NEC violation are closely related [ 7 , 8 ]. It is realized that the NEC violation is a generic feature of warp drive spacetimes [ 6 ]. (ii) The Alcubierre drive requires an unphysically large amount of negative energy, so there appears no practical way to create an Alcubierre drive even if we have control of NEC-violating matter [ 9 , 10 ]. (iii) In the superluminal region, the warp bubble suffers from a “horizon problem”: there are event horizons that prevent any observers inside the spaceship to interact with the bubble [ 11 ]. (iv) A superluminal warp drive metric leads to quantum instabilities [ 12 , 13 , 14 , 15 ]. (v) To move the warp drive, the flux of the NEC-violating matter is superluminal. It thus becomes a chicken-and-egg problem of how to move the NEC-violating matter in a superluminal way in order to start the warp drive. One of the main focuses of this field is to solve the above theoretical puzzles, see for example [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ].

In this paper, we investigate the possibility of superluminal travel through warp drive scenario in another prospective. The above works are concerned with the feasibility of a warp drive metric, while we focus on the potential problems arise in the process superluminal travel. That is, even if we could overcome all puzzles listed above and construct a warp bubble, the additional challenges preventing us from superluminal travel is still severe. We consider two situations that occurs during the interstellar travel. Firstly, a real spacecraft with non-zero volume will feel a “distortional” force due to the nontrivial curvature gradient. Secondly, as indicated by [ 12 ], the warp drive metric will accumulate particles in the front part of the bubble, so interstellar matters will be “attracted” and collide with the spacecraft. We study the case for two typical interstellar matter, dusts and photons, and work out the condition for them to collide with the spaceship, the energy shift when the collision happens, and the collision frequency. Then we combine all these results and get the dependence of pressure felt by spaceship on its apparent velocity \(v_s\) . We find that, although in both cases the pressure depends on \(v_s\) linearly when the spaceship is placed at the center, the \(v_s\) dependence of photon comes from the energy shift, while that of dust comes from the collision frequency.

The paper is organized as follows. We briefly introduce the warp drive scenario in Sect.  2 , and then work out the distortion force exerted on the spaceship in Sect.  3 . After that, the geodesic of matter in the warp drive spacetime is studied in Sect.  4 , and the total effect on collision between spaceship and interstellar matter is presented in Sect.  5 . We finally conclude in Sect.  6 .

2 The Alcubierre warp drive spacetime

2.1 the warp drive metric.

The geometry of the Alcubierre warp drive [ 1 ] is described as Footnote 1 :

Here, the parameter \(r_s\) refers to the distance between any spacetime point ( x ,  y ,  z ) and the center of the bubble. The function f should vanish at a large distance for the spacetime to be asymptotically flat, and becomes a unit at the center of the bubble for the bubble to travel at an apparent velocity \(v_s\) . Footnote 2 A specific expression of f provided by Alcubierre is

and plotted in Fig.  1 .

\(f(r_s)\) for a warp bubble with \(R=2\) , \(\sigma = 1\) or \(\sigma = 10\) . Here, R is the radius of the bubble and the parameter \(\sigma \) describes the thickness of the bubble. For large \(\sigma \) , f approaches to a step function

We can understand the warp drive geometry more easily in the limiting case \(\sigma \rightarrow \infty \) . In this limit, f approaches a step function with \(f=1\) for \(r_s < R\) and \(f=0\) for \(r_s > R\) . Recall that R is the radius of the warp bubble, we see the spacetime outside the warp bubble remains quasi-Minkowskian, while the “internal” of the bubble propagates along the x axis with an apparent velocity \(v_s\) . Since there is no fundamental limit on the parameter \(v_s\) , we can take it as large as possible, so the warp bubble can take a distant trip with arbitrarily short time.

2.2 Frame of reference in the warp drive spacetime

The metric ( 2.1 ) describes the global geometry of the spacetime. However, to clarify physical meaning of quantities calculated, a local observer is required. For example, to work out the interaction between particles and the spaceship, we need to parallel-transport their 4-velocities to the same spacetime point and take the inner product in the associated tangent space.

A natural choice of the local observer is the one associated with the spaceship itself. However, in the local frame of the spaceship, there exist event horizons; moreover, parallel transport of any vector crossing the warp bubble would be mathematically complex. Hence, in this paper, we would prefer to work with an observer remoted from the warp bubble, whose existence is ensured by the asymptotical flatness nature of the metric ( 2.1 ).

3 Distortion force

Since the warp drive spacetime is curved, we expect a distortion force acting on the spaceship with finite volume. If the gradient of the curvature is large enough, the resulting distortion force may have a significant impact on the spacecraft and then interfere with the superluminal travel. Since in reality, the most important parameter we concern in warp drive metric ( 2.1 ) is \(v_s\) , which determines the efficiency of the superluminal travel, we will fix R and \(\sigma \) and determine the dependence of distortion force on \(v_s\) .

For simplicity, we will work in a “comoving” coordinate ( \(t,{\bar{x}},\rho ,\theta \) ), related to the original coordinate by

so \({\bar{x}}\) is the apparent x coordinate of any spacetime point viewed by the center of the bubble. The apparent velocity is \({\bar{v}} = d{\bar{x}}/d\lambda \) . The metric is

note that \(\theta \) is absent in the metric due to the axial symmetry of warp drive spacetime.

For a realistic interstellar travel, the spaceship had better not to receive too much deformation during the trip. More precisely, we wish for any two neighboring points on the spaceship A and B, their “distance” \(r_{AB}\) remains roughly invariant. Here we do not require our spaceship to be a rigid body with constant \(r_{AB}\) , but to ask the deformation \(\Delta r_{AB}\) is small compared to \(r_{AB}\) . In the comoving frame, this means that the velocity of all the points on the spaceship should vanish, i.e. \(d v^{\mu } / d \lambda \approx 0\) and \(v^i \sim 0\) . However, the geodesic equation

tells that, in the comoving coordinate, any point other than the center of the bubble would have a non-trivial velocity due to the non-zero Christoffel symbol. Hence, there must be an external four-force \(F^{\mu }\) to balance the curvature term in the geodesic equation. Now, with the external force \(F^{\mu }\) , the geodesic equation becomes

Note that the distortion of the spaceship comes from the curvature term \(\Gamma _{\nu \chi }^{\mu }{\bar{v}}^{\nu }{\bar{v}}^{\chi }\) , so in principle, we shall call this term the distortion force. On the other hand, \(F^{\mu }\) is the force resisting the deformation, which comes from the stiffness of the spaceship. Here for simplicity, we shall call \(F^{\mu }\) as distortion force since, in our case \(\frac{d {\bar{v}}^{\mu }}{d \lambda } \simeq 0\) and \(F^{\mu } \simeq -\Gamma _{\nu \chi }^{\mu }{\bar{v}}^{\nu }{\bar{v}}^{\chi }\) .

Since \(v^i \sim 0\) , the only non-trivial component of ( 3.4 ) is \(\nu = 0\) , \(\chi = 0\) , which gives

which is the desired distortion force (or, more precisely, the distortion force density). The geodesic equation ( 3.4 ) is valid in any coordinate, and \(F^{\mu }\) is covariant. Thus, \(F^{\mu }\) is invariant under a coordinate transformation, and we can express it in a certain coordinate for simplicity. Here, we choose to work in the comoving coordinate and express \(F^{\mu }\) in the component form. Since the system enjoys axial symmetry, \(F^{\theta } = 0\) , and the rest non-trivial spatial components are

where we define two auxiliary functions

Vector plot of the distortion force for a warp bubble with parameters \(\sigma =1\) , \(R=20m\) , \(v_s=2c\)

We plot the distortion force in Fig.  2 for a practical warp bubble to comprehensively illustrate its behavior. We also plot the x and \(\rho \) components of the distortion force as a function of positions in Figs.  3 and  4 .

We see from Fig.  3 that \(F_x\) is relatively small near \({\bar{x}} = 0\) and \(F_x = 0\) at \({\bar{x}} = 0\) . This can be seen from our auxiliary function \(a(r_s)\) , since \(a(0) = 0\) and \(a'(0)\) is suppressed by the hyperbolic functions. The result suggests we put the spaceship in the \(y-z\) plane, and the distortion force on x direction would be minimized.

Figure  4 shows that for a certain warp bubble, \(F^{\rho }\) takes its maximum near \(\rho = R\) , and its everywhere positive except for two zero points, \(\rho \rightarrow \infty \) and \(\rho =0\) . A detailed proof can be found in Appendix B.

Now we can conclude our result. From Eqs. ( 3.6 ) and ( 3.7 ) we see \(F_x \propto v_s^4\) and \(F_\rho \propto v_s^2\) . However, \(F_x\) can have at most three zero points, one is \({\bar{x}} = 0\) , the other two is expressed by the condition

and the details are in Appendix B. Besides, \(F(\rho ) = 0\) when \(\rho =0\) . Hence, we can always place our spaceship at the center to make distortion force minimized. However, since a real spaceship has a finite volume, it will still feel a non-trivial force which scales as \(v_s^2\) and \(v_s^4\) in radial and longitudinal direction respectively.

The \({\bar{x}}\) component of the Tidal force with a \(\rho =0\) , b \(\rho =1\) as a function of \({\bar{x}}\) for different \(v_s\) . Warp bubble parameters are \(R=2\) , \(\sigma =1\) in natural unit

The \(\rho \) component of the distortion force with a \({\bar{x}}=0\) , b \({\bar{x}}=1\) as a function of \(\rho \) for different \(v_s\) . Warp bubble parameters are \(R=2\) , \(\sigma =1\) . All numerical values are in natural units

4 Motion of particles in the warp drive spacetime

In this section, we work out the motion of particles in the warp drive spacetime, and see whether these particles can collide with the spaceship. We also evaluate the energy shift of these particles. It is generically difficult to evaluate the geodesics with arbitrary initial conditions. However, as we will see later, the collision effect depends linearly on \(v_s\) if the spaceship is placed at the center of the bubble, which is small compared to the distortion force when \(v_s \gg c\) . Hence, if a deviation of the center cannot contribute a \({\mathcal {O}}(v_s^3)\) factor, then the collision effect would be subdominant compared to the distortion force. Hence, in our preliminary investigation here, we will only work out the case when the spaceship is right at the center of the bubble. A more complete study would be left for further investigation.

4.1 Geodesic equations

Given the warp drive metric ( 2.1 ), we can work out the corresponding Christoffel symbols, which we present in Appendix A. The geodesic equation is then

where \(\lambda \) is the affine parameter.

The geodesic equation ( 4.1 ) can then be decomposed into four differential equations

where the dot refers to the derivative with respect to the affine parameter \(\lambda \) . For convenience, we define the 4-velocity of an object as \(U^{\mu } \equiv d x^{\mu }/ d\lambda \) . Fortunately, we do not need to go through the full equations. Note that the dust particles should have negligible initial velocity compared to the speed of light in view of a static observer. Hence, in the comoving coordinate, the dust particle should have a conserved angular momentum, perpendicular to the plane determined by the velocity vector \(\mathbf {v}_s\) and the line connecting the dust and the center of the bubble. A similar argument also applies to the photon case. The conserved angular momentum ensures that the particles only travel in the plane. Thus, it is sufficient to consider only two coordinates. Footnote 3 Hence, we may safely suppress the z coordinate and take \({\dot{z}} = 0\) when evaluating equations ( 4.2 ) and ( 4.3 ).

4.2 Dynamics of photons

One main component of interstellar matter is the free photons. In this section we consider the interaction of a single photon with the warp bubble, and determine the energy shift of the photon.

Fortunately, for our concerned case where the spaceship is placed at the center, the trajectory of the photons which could meet with spaceship, as well as the energy shift, i.e., the ratio of photon energy when it hits the spaceship to its energy far from the spaceship, is studied in [ 29 , 30 ]. Here we directly present their results.

Firstly, the apparent angle of the four-velocity of the photon when approaching the spaceship approaches 0. By apparent angle, we mean the angle between the x -axis and the four velocity of the photon, which we illustrate in Fig.  5 . This means that

The original scenario where the particles propagate from infinity to the center of the bubble, shown in a , is equivalent to that in b , where a particle is emitted from the center of the bubble. The photon cannot go outside the bubble unless the apparent angle \(\zeta \) approaches 0

We are also interested in the energy shift of the photon. The result from [ 29 ] shows the photon energy shift \(\eta _p\) is:

where \(r_s\) is the apparent distance between the photon and the spaceship viewed from a remote observer. When \(v_s\gg c\) , the energy shift simplifies to

4.3 Dynamics of dust matter

Another important matter content in interstellar space is dust. Usually, dust will have a speed much smaller than the speed of light, so for a warp bubble with superluminal speed, we can safely set their speed to zero when they are remote from the bubble. Hence, the boundary condition for the geodesic equation is set to be

and for each dust particle with y coordinate \(\lim _{r \rightarrow \infty } y = y_0\) , we can uniquely determine its geodesics.

We numerically evaluate the geodesic equation with different \(y_0\) , and the trajectories are illustrated in Fig.  6 . We see the dust particles entering the warp bubble from rest will tend to move towards the center of the bubble, but will not exactly reach the center. The dust particles with a larger initial y position will arrive at the x–z plane further away from the spaceship. This is consistent with the numerical result by [ 30 ].

The trajectories of dust particles with a large initial x position, and initial y positions at \(y=0.5\) , \(y=0.75\) , \(y=1\) , \(y=1.25\) and \(y=1.5\) respectively. The parameters of the warp bubble read \(\sigma =10\) , \(R=2\) , \(v_s=100\) . All numerical values are in natural units. Here, \(x'_s \equiv x-v_st\) represents the apparent distance of dust and spaceship in x axis, so \(x'_s = 0\) means spaceship and dust have the same x coordinate in the view of the remote observer

One may notice that, in Fig.  6 , the point where the trajectory of the dust particles starts to shift is inside the bubble. This comes from the fact that, with respect to the bubble, the particle carries a large initial velocity along x-direction, while it takes some time to accelerate along y-direction.

We can comprehensively understand the result in Fig.  6 in another way. It is found that in a generic warp drive spacetime, the Ricci scalar has the greatest impact on the surrounding spacetime [ 31 , 32 ]. This reaches an agreement with our result. One may find from Fig.  6 that the acceleration of the dust reaches its maximum near the boundary of the warp drive bubble, where the trajectory starts to bend. The maximum value of the gradient of the Ricci scalar is also near the boundary of the bubble. This means that dust acceleration is positively correlated to the gradient of the Ricci scalar.

In order to calculate the energy of the collision, we need the four velocity of the particle at the collision event. The four velocity can be calculated from the apparent velocity of the particle when arriving at the center of the bubble, i.e., the apparent velocity of the particle viewed from the spaceship, which we will call the final velocity for simplicity. To study the properties of the final velocity, we numerically integrated the geodesics equations ( 4.2 ) and ( 4.3 ) for a dust particle. This particle starts at rest far away from the warp bubble. Its initial velocity is set by Eq. ( 4.8 ). As discussed above, for a spaceship located at the center of the bubble, dusts with initial coordinate \(y_0 \ne 0\) is hard to hit the spaceship. Thus, it suffices to consider the dusts with \(y_0 \simeq 0\) only. We depict the result in Fig.  7 . We see that under the high-speed condition, the x-component of the final velocity of these dust particles approaches to \(v_x=v_s-c\) . In the frame of a remote observer, the four velocity of the particle can be formally written as

The Eq. ( 4.9 ), along with the normalization of \(v^{\alpha }\)

gives the expression

Note that the four velocity is imaginary, this is because the particles, when inside the bubble, travels along a spacelike geodesics viewed by a remote observer. Similarly, since the apparent velocity of the spaceship is \(v_s\) , we can work out its corresponding four-velocity

The energy of the dust particle per unit mass seen by an observer on the spaceship is thus:

Note that, the energy is a scalar coming from the inner product of two vector, so its value is independent of the reference frame we choose, so we can evaluate it in a remote observer for simplicity.

We can conclude from the above result that, under high speed condition \(v_s \gg c\) , a dust particle entering the warp bubble will interact with the spaceship with energy \(E_d\propto v_s^0\) .

The final apparent velocity minus the speed of the bubble as a function of the speed of the bubble, measured in a remote observer. The dust particle starts at rest at x = 2.5, y = 0, and the parameters of the bubble are \(R=2\) , \(v_s=20\) , and \(\sigma =10\) . All numerical values are in natural units. The center of the bubble is placed at \(x=0\) at start

The apparent velocity as a function of \(v_s\) , measured in a remote observer. The parameter of the bubble read \(R=2\) , \(v_s=20c\) , and \(\sigma =10\) . The center of the bubble is placed at \(x=0\) at start. Figure  7 a shows the x component of the velocity of the dust particle at the center minus the speed of the bubble as a function of \(v_s\) , with initial position of the particle to be \(x=2.5\) and \(y_0 = 0.5\) , 1.0, 1.5 respectively. Figure  7 b shows the y component of the velocity of the dust particle at the center as a function of \(v_s\) , with initial position of the particle to be \(x=2.5\) and \(y = 0.5\) , 1.0, 1.5 respectively. All the velocities here are the apparent velocities measured by a remote observer. All numerical values are in natural units

Finally, for completeness, we also plot the final velocity of a dust particle entering the bubble with initial coordinate \(y \ne 0\) in Fig.  8 . Similar to the above case, the final velocity approaches a certain value for large \(v_s\) . We can read from the plots that, as the initial y position increases, the final velocity along the x-axis decreases. Thus, the head-on collision between the dust particle and the spaceship is weakened. Besides, the combination of Fig.  8 a, b tells that, the total apparent velocity of the dust particle approaches the speed of light for large \(v_s\) . Hence, the condition \(v_x = v_s - c\) for the \(y_0 = 0\) case can be regarded as a specific case with \(v_y = 0\) .

5 The pressure caused by photons and dust particles in the interstellar space

Now that we get the trajectory of photons and dust particles as well as their energy shift at collision event, the rest thing we shall do is to work out the frequency of the collision. After that, we can get the dependence of collisions on \(v_s\) .

5.1 Photon collision

Since the photons colliding with spaceship at the center will all have a vanishing apparent angle \(\zeta \) , we may take the following simplification. We take \(\sigma \) to be large enough, such that the spacetime when \(r_s<R\) and \(r_s > R\) are almost flat. Hence, the photons colliding with the spaceship must enter the bubble through the neighborhood of the spatial point \((v_s t,0,0)\) , the area of the neighborhood denoted as \(\Delta A\) . Moreover, since light rays emitted at \(\Delta A\) with any incidence angle will all have a vanishing apparent angle inside the bubble, the photons colliding with the spaceship at a certain time must originate from a spherical shell. We illustrate the above point in Fig.  9 .

Since the position and velocity of interstellar photons are randomly distributed, we see that the collision frequency should be proportional to the differential volume of the photon layer. In this case, the total momentum \(d p_p\) of photons travelling towards the area \(\Delta A\) in an infinitesimal time dt comes from a certain solid angle \(d\Omega \) is:

where \(p_{av}\) is the average momentum value of the interstellar photons. For each photon through the bubble, the blue-shift causes its energy to increase by \(\eta _p \sim v_s/c\) , so the total momentum of photons at the bridge within time dt is:

Here \(E_{av}\) is the average energy of interstellar photons \(E_{av}\) . The interaction of the high-energy photons with the spacecraft will lead to the momentum transfer, causing the light pressure \(P_p\) on the foredeck.

where n is the reflection coefficient of the spacecraft foredeck. We can thus conclude from Eq. ( 5.3 ) that the pressure from photon collision is proportional to the spacecraft apparent velocity \(v_s\) .

The photon layer. The photons which will arrive at the center of the bubble after time t are laying on a shell with radius \(R=ct\) and thickness cdt . The distance between the center of the bubble and the center of the shell is \(v_st\)

5.2 Dust particle collision

The velocity of interplanetary dust particles, which is typically around \(10^{-4}c\) , is extremely small compared to the velocity of our warp bubble. The dust particles that hit the warp bubble will therefore be mostly those staying on the cylinder that our warp bubble swaps through. At the same time, since the spaceship is much smaller than the warp bubble, we consider our spaceship as a point sitting at the center of the bubble. In this case, the total momentum \(dp_d\) of dust particles entering the warp bubble in an infinitesimal time dt is:

where \(p_{av}'\) is the average momentum value of dust particles. The average pressure caused by dust particles at the bridge is thus:

where n is the reflection coefficient of the spacecraft front deck. We see the collision with photons and dust particles will both contribute a pressure proportional to \(v_s\) .

6 Conclusion and outlook

We considered two possible obstacles on the warp drive spacecraft through interstellar travel and calculated their dependence on the speed of the warp bubble \(v_s\) . Our results shows that when \(v_s \gg c\) , the distortion force scales as \(v_s^2\) and \(v_s^4\) in radial and longitudinal direction respectively, and would be minimized when we place the spaceship in the center of the warp bubble. The pressure on the front deck of the spacecraft caused by the interstellar photons and dust particles collision is proportional to \(v_s\) , and hence subdominant compared to the distortional force.

Our work can be extended in various directions. Firstly, we may consider a warp bubble with varying speed \(v_s\) , and see whether non-trivial accelerations may lead to new phenomenons. Secondly, investigations on the collision effect when spaceship is not placed at the center may be interesting. Thirdly, it is interesting to study whether dark matter or even dark energy can interact with the warp bubble as well as the spaceship. Finally, a stability check, on both classical and quantum levels, is worth studying.

Data Availability

This manuscript has no associated data or the data will not be deposited. [Authors’ comment: The paper is a purely theoretical study without using any experimental data.]

Alternative constructions of warp drive spacetime can be found in [ 28 ].

In this paper, we consider the case of constant speed \(d v_s/ d t = 0\) for simplicity.

The case is similar to an unbounded trajectory of a point mass around a compact object, e.g. the deflection of light by the Sun. The conservation of angular momentum restricts the movement to be two-dimensional.

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Acknowledgements

We thank Qianhang Ding, Chon Man Sou, Xi Tong, Shengfeng Yan, Jinbo Yang and Siyi Zhou for helpful discussions. This work was supported in part by the National Key R &D Program of China (2021YFC2203100), and the NSFC Excellent Young Scientist Scheme (Hong Kong and Macau) Grant no. 12022516.

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Appendix A: Christoffel symbols

In this appendix, we provide all the non-zero Christoffel symbols under the warp drive metric \(g_{\alpha \beta }\) :

Appendix B: Stable surface under the distortion force

In this appendix, we will show that we cannot find any surface where \(F^{\rho }=0\) except for the trajectory where \(\rho =0\) , but a surface with \(F^{{\bar{x}}}=0\) is possible. We define a new function \(n(\sigma ,r_s)\) as:

Now that \(r_s<R\) for our spaceship, and since \(\tanh {x}\) is a concave function for \(x>0\) , we immediately know that \(n(\sigma ,r_s) < 0\) , which means

Thus, the only place where \(F^{\rho }=0\) is along the \({\bar{x}}\) axis. However, we can make \({\bar{x}}\) component of the tidal force zero, \(F^{{\bar{x}}}=0\) , by imposing:

Together with Eq. ( B.2 ), we obtain the requirement for a sphere with zero \(F^{{\bar{x}}}\) :

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Bian, S., Wang, Y., Wang, Z. et al. Obstacles from interstellar matters and distortion in warp drive superluminal travel scenario. Eur. Phys. J. C 82 , 861 (2022). https://doi.org/10.1140/epjc/s10052-022-10840-w

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DOI : https://doi.org/10.1140/epjc/s10052-022-10840-w

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How Humans Could Go Interstellar, Without Warp Drive

Faster-than-light (ftl) travel is possible..

The field equations of Einstein’s General Relativity theory say that faster-than-light (FTL) travel is possible, so a handful of researchers are working to see whether a  Star Trek -style warp drive, or perhaps a kind of  artificial wormhole , could be created through our technology.

But even if shown feasible tomorrow, it’s possible that designs for an FTL system could be as far ahead of a functional starship as Leonardo da Vinci’s 16th century drawings of flying machines were ahead of the Wright Flyer of 1903. But this need not be a showstopper against human interstellar flight in the next century or two. Short of FTL travel, there are technologies in the works that could enable human expeditions to planets orbiting some of the nearest stars.

Picking the Target

Certainly, feasibility of such missions will depend on geopolitical-economic factors. But it also will depend on the distance to nearest Earth-like exoplanet. Located roughly 4.37 light years away, Alpha Centauri is the Sun’s closest neighbor; thus science fiction, including  Star Trek , has envisioned it as humanity’s first interstellar destination.

In 2012, a planet was  identified  orbiting closely around Alpha Centauri B, one of three stars comprising the Alpha Centauri system. Three years later, astronomers were unable to find that same planet, but if it exists it would be too hot for life anyway. What we really want to know is whether planets exist further out from the two main stars, or whether their much smaller, dimmer companion star, Proxima Centauri, located just 4.24 light years from Earth, has planets of its own.

Very soon, these questions will be answered by the  James Webb Space Telescope (JWST) that NASA will be launching into space in 2018, and by other instruments that will follow, instruments capable of more than merely detecting a planet’s presence. They will also be able to read the chemical composition of planetary atmospheres.

Imagine this: If there’s an Earth-like planet around Alpha Centauri or another nearby star system, astronomers will know about it within a decade or two — certainly long before we can build a ship like the  Enterprise .

Maybe we could consider flying under the speed of light.

Propulsion 

It is not widely known, but the US government spent real money, tested hardware and employed some of the best minds in late 1950s and early 60s to develop an idea called  nuclear pulse propulsion .

Known as  Project Orion , the work was classified because the principle was that your engine shoots a series of “nuclear pulse units” — atomic bombs of roughly Hiroshima/Nagasaki power — out the back. Each unit explodes and the shockwave delivers concussive force to an immense, steel pusher plate, which is connected to the most immense shock absorber system that you could imagine.

The researchers calculated that the ship could reach five percent the speed of light (0.05  c ), resulting in roughly a 90-year travel time to Alpha Centauri. The Nuclear Test Ban Treaty of 1963, which forbade nuclear explosions in the atmosphere, and the Outer Space Treaty of 1967, which forbade nuclear explosive devices in space, effectively ended  Orion .

In his epic TV series Cosmos, Carl Sagan noted such an engine would be an excellent way to dispose of humanity’s nuclear bombs, but that it would have to be activated far from Earth. But back when  Orion  was being funded, amazingly, the plan was to use the nuclear pulse engine even for launching the vessel, in one massive piece, from the surface of Earth. Suffice it to say it does not seem likely that we’ll every build a nuclear pulse ship, but it’s something that we already have the technology to build.

A Cleaner System

But what about a less explosive, cleaner propulsion system that could achieve the same end? The British Interplanetary Society took on this goal in the 1970s with Project Daedalus . Named for the inventor from Greek mythology who built wings to escape the island of Crete, the design was based on projected development of inertial confinement fusion (ICF), one of two main strategies for generating nuclear fusion energy on Earth.

The other strategy is magnetic confinement fusion (MCF), and similar to ICF, designs exist for  adapting MCF to space propulsion . Like  Orion , a  Daedalus  craft would have to be rather large. But using deuterium and helium-3 (obtained from the lunar surface, or from Jupiter’s atmosphere) as fuel,  Daedalus  craft could reach 0.12  c , cutting travel time to Alpha Centauri to something like 40 years.

There are other ingenious ideas, such as the  Bussard ramjet  that could approach the speed of light, but the size of the engines and technological gaps that we must fill become so large that they may not seem easier than warp drive. So let’s limit our discussion to capabilities up to the neighborhood of the 0.12  c  of  Daedalus  as we consider what form a human interstellar voyage might take

The Generation Starship

It has been said that if you want to go fast, go alone, but if you want to go far, go together. This proverb characterizes the strategy of building an interstellar ship so large that you don’t worry so much about the travel time.

Effectively, the ship is a space colony. It contains a large population — current estimates are that a minimum of tens of thousands of colonists are needed for a  healthy gene pool — and all that is needed for people to live comfortably, but it follows a trajectory out of the solar system. Ideas for an interstellar ark taking millennia to reach a destination date back to the fathers of the Space Age — Russia’s Konstantin Tsiolkovsky and America’s Robert Goddard— — the idea really set sail with mid 20th century science fiction writers.

In a two-part novel series written in 1941, Robert A. Heinlein wrote of a vessel that took so long to reach its destination that the people aboard had forgotten they were on a ship. Instead, they believed the large craft to be their natural world.

Sending colonists on a voyage lasting centuries or millennia raises social questions, such as whether it is ethical to commit unborn generations to live out their lives in transit between planets.

10,000 years is a rather long time and means a large number of generations to commit to the interstellar void. But if we’re talking 40 or even 90 years, that’s probably more palatable to many more people. Still, it raises questions as to who would volunteer for such an expedition.

But what about people with shorter attention spans and what if we have no will to build enormous, moving colonies?  

Here’s another science fiction strategy: sending cryopreserved human embryos, or gametes (ova and sperm) into deep space. Upon reaching the destination star system, the embryos would be developed. This would require an artificial uterus, which we don’t have yet, but like fusion, here we’re also talking in terms of a matter of decades.

At some point in this century,  motherless birth  could become a technological reality. Theoretically, we’ll be able to send cryopreserved embryos through space, for centuries if needed due to propulsion limitations, and set them to develop into full-term infants on the new planet.

Then, all you need are robot nannies to raise and educate the infant colonists. And if there’s one area of technological progress that people are supremely confident will keep advancing at warp speed, it’s robots and artificial intelligence.

The egg ship concept is loaded with ethical questions, which can be hashed out in the comments section.

Suspended Animation

As technically ambitious as it may sound, medical science is making incremental progress toward a safe form of human hibernation.

Currently, it’s routine to lower a patient’s body temperature intentionally by a few degrees, thereby inducing a mild hypothermic coma, following cardiac arrest. This enables the brain to recover after oxygen has been cut off, whereas remaining at normal body temperature results in what’s called reperfusion injury.

Not routine yet, but now under clinical trials, trauma surgeons are cooling patients down to just above freezing temperature in cases of severe blood loss. This is true  suspended animation . It’s done just for two hours, or possibly three, stalling death so that injuries can be repaired and blood replaced, but the person is basically hibernating during that time.

With incremental progress, the procedure may eventually be extended to time frames of many hours, and eventually days or weeks to treat other conditions. Perhaps, in time, we’ll put people to sleep long enough, and with enough supervision by computers, to slumber away for an entire interstellar voyage the way you now doze off for a transoceanic flight.

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NASA’s Quest for Warp Drive Technology

Space is vast. Its unimaginable scale means that even at light speed, we’re years away from the nearest star systems. But despite these immense distances, human curiosity and ambition have never waned. The desire to explore, understand, and potentially conquer the cosmos is as strong as ever. But can our technology ever match our ambitions?

Pushing Technological Boundaries

It’s not just about achieving high speeds. True space exploration demands light speed technology – a challenging feat. However, with challenges come innovations. NASA is currently leading the way, pioneering research to make light speed travel a reality.

Understanding Warp Drives

Warp drives aren’t just science fiction fantasies from Star Trek. These technologies could potentially bend space, allowing for quicker interstellar travel. The concept, termed the Alcubierre Drive, was first introduced by physicist Miguel Alcubierre in 1994.

At its core, this drive would manipulate space-time to form a protective bubble around the ship. Inside this bubble, the distances become shorter, making light-speed achievable. It’s a concept born from Einstein’s theory of general relativity, which explores how space-time bends due to matter and energy.

Challenges and Solutions

But challenges abound. The energy requirement for the Alcubierre Drive is colossal. Current methods simply cannot generate this magnitude of power. However, scientist Eric Lentz offers an alternative: a soliton-based space-time bubble, which could be achieved with contemporary energy techniques. If successful, NASA could achieve light-speed without monumental energy requirements.

Warp Speed Consequences

Yet, achieving warp speed presents other challenges. The sheer velocity could expose ships and their crew to hazardous particles, demanding specialized shields. Plus, the bending of space-time would have time dilation effects. A journey to the Alpha Centauri star system might take a mere five days for astronauts, but over eight years would pass on Earth. The ramifications on interpersonal relationships and human psychology could be profound.

A Future with Warp Drives

Warp drive technology remains in its infancy, yet the progress being made is inspiring. There’s a hope that in the not-so-distant future, such drives could be as ordinary as the rockets we use today. After all, the moon landing once seemed an impossible dream.

While warp drives are a focus, NASA’s current projects continue to astonish. For instance, their recent revelations about Jupiter have left scientists astounded.

Space remains the final frontier, and with organizations like NASA pushing boundaries, the future promises exciting discoveries.

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Nasa technologist talks what’s needed for interstellar travel.

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Interstellar travel is one of the most frustrating topics in all of astrophysics. Despite hundreds of articles, movies and TV shows devoted to the subject, in most professional astronomical circles the issue seems about as welcome as the Grinch at Christmas.

It's a fascinating topic. But no one can say with certainty that humans will ever be able to send robotic probes to visit another star system, much less colonize an extrasolar earthlike planet.

And, sadly, none of the major space agencies seem to have a long-term itch to send spacecraft on dedicated interstellar precursor missions.

Sending a 500 kg – 1000 kg robotic spacecraft to another star with a realistic travel time of a few hundred years will not likely be technologically feasible for another 75 – 150 years, Les Johnson, author of “A Traveler's Guide to the Stars,” and a propulsion technologist at NASA Marshall Space Flight Center, told me via email. But he admits that if in 1990 someone had asked him how long it would take for Earth to have its current system of global telephony, he would have said far longer than it’s taken.

Even though Johnson is a longtime advocate of interstellar propulsion research, he is emphatic to note that his views on the subject are not NASA’s but rather very much his own. All of which begs the question: Why do mainstream rocket scientists and theoretical physicists appear to be so reluctant to discuss interstellar propulsion?

The distances are vast, and the energies required are almost unimaginably large, says Johnson. Thus, the steps we must take between today’s state of the art and the propulsion systems required are so numerous that they consider it to be science fiction, he says. Traveling to the stars is important, but we will likely not seriously begin considering them until we are masters of our own solar system, says Johnson.

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What should we be doing to make interstellar travel possible?

“We need to bring back funding for basic research and development and run away from the notion that all R&D must have a near-term return on investment,” said Johnson.

Some form of warp drive is likely the most feasible way to enable realistic Star Trek-styled travel since each warp factor is a multiple of the speed of light cubed. As Johnson explains in “A Traveler’s Guide to the Stars,” Warp drive “uses tremendous energies to change the shape of space-time, allowing the ship to cross normal, albeit warped/compressed/expanded space very quickly.”

In a now-famous 1994 refereed paper, Mexican theoretical physicist Miguel Alcubierre describes a warp drive that “works mathematically and would allow a starship to appear to be traveling faster than light, while not really doing so,” Johnson notes in his book.

Can Alcubierre’s warp drive work?

The Alcubierre Drive postulates that a spaceship might appear to move faster-than-light by contracting space in front of it and expanding space behind it, thereby riding spacetime like a surfer rides a wave, says Johnson.

“After the ship crosses the contracted space-time, it expands back to normal size behind the ship, leaving nature beautifully intact and space-time undisturbed, with the ship appearing to move much faster than light,” Johnson notes in his book.

The mathematics is “elegant,” but to achieve the energies necessary to make the Alcubierre Drive a reality would require the existence of negative mass (where 1 kg would be -1kg), says Johnson. No one has ever detected negative mass and there is no evidence that it exists, he says. And until we find some, the Alcubierre Drive will remain speculative physics, says Johnson.

A Traveler's Guide to the Stars

So, when can we expect human astronauts to touch down on an Earth 2.0?

The likelihood of finding an Earth 2.0 anywhere in the galaxy is very small, but probably not zero, says Johnson. However, the chances of finding it relatively close to Earth are so small as to be rounded to zero, he says. That does not mean we will not take such voyages; it does mean that we will likely need to not only learn how to travel to distant stars, but also how to terraform distant planets to make them truly habitable, Johnson says.

Does technology that could take us to the stars already exist in someone’s lab here on Earth?

It’s possible that the big new idea that brings interstellar travel closer to reality has already been envisioned by someone, somewhere in the world, says Johnson. But to meet the challenges of interstellar travel, we will need many big, new ideas and approaches, he says.

To that end, this coming July in Montreal, Johnson and colleagues are taking part in The 8th Interstellar Symposium, an interdisciplinary, global meeting of researchers working to one day make interstellar travel possible.

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Interstellar may be the first movie that shows realistic warp travel

At last we got to see the full trailer for Chris Nolan's Insterstellar . The drama seems centered around a worldwide food crisis fired by climate change and resource depletion—a quite probable future. The space travel part seems equally plausible, showing what may be the first realistic depiction of a real warp drive.

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Of course, warp drives are not real . Yet (hopefully?) But physicist have theorized about it and NASA has a small group of people working on them. I'm firmly in the camp of "if we can imagine it, we can build it." But we will get to that later. Watch the trailer first:

The realistic climate change and resource scarcity scenario

I completely buy the trailer's vision of a future weather and resource global crisis . The global data is unquestionable. Man-made or not, I don't care, the fact is that climate change is happening. It's drastic and it's accelerating, and we may not be able to stop it at this point.

Computer simulations show that we are headed to a place where humanity hasn't been before. The projections are so bad that the military have deemed it a national security threat already. And trust me, the men and women of the Pentagon are not tree-hugging hippies.

As climate changes, everything changes. We are already seeing the effects on agriculture, with ruined crops and food scarcity in many parts of the world. Or better said, we are not seeing it—people who live in third world countries are. Our oceans' fisheries are also dwindling quickly, with many species on the verge of exhaustion.

Combine this with the millions of poor people getting out of poverty conditions in China, India, South America and Africa. They are consuming more and more of resources that are already scarce. More food. More energy. More oil. More everything. Even if the population doesn't go up, the demand will keep increasing at a fast rate. It's not going to stop.

Still, I'm an optimistic person who thinks that science may save us at the last minute. Perhaps that's Nolan's thesis—or perhaps it's the contrary. We don't really know yet. But I have no doubt that we are headed into this direction.

A hopefully possible interplanetary travel scenario

In the trailer we can see the space crew going into this:

It's some sort of portal, some gravitational bubble that looks very much like this picture of a gravitational lens seen by the Hubble Space Telescope.

It's been reported that Nolan has been talking to astrophysicists and aerospace experts about it. I'm sure one of them has been Dr. Harold "Sonny" White, at the Advanced Propulsion Theme Lead for the NASA Engineering Directorate. Back in 2012 I wrote this article about his efforts, explaining why something like the type of travel portrayed in Interstellar may become a reality. It's reproduced below:

"Perhaps a Star Trek experience within our lifetime is not such a remote possibility." These are the words of Dr. Harold "Sonny" White , the Advanced Propulsion Theme Lead for the NASA Engineering Directorate. Dr. White and his colleagues don't just believe a real life warp drive is theoretically possible; they've already started the work to create one.

Yes. A real warp drive, Scotty.

When it comes to space exploration, we are still cavemen. We got to the Moon and sent some badass robot to Mars . We also have those automatic doors that swoosh wide open when you get near them, but that's about it. It's cool, but we are far from being the space civilization we'll need to become to survive for millennia.

With our current propulsion technologies, interstellar flight is impossible. Even with experimental technology, like ion thrusters or a spaceship's aft pooping freaking nuclear explosions, it would require staggering amounts of fuel and mass to get to any nearby star. And worse: it will require decades—centuries, even—to get there. The trip will be meaningless for those left behind. Only the ones going forward in search for a new star system would enjoy the result of the colossal effort. It's just not practical.

So we need an alternative. One that would allow us to travel extremely fast without breaking the laws of physics. Or as Dr. White puts it: "we want to go, really fast, while observing the 11th commandment: Thou shall not exceed the speed of light. "

Searching for warp bubbles

The answer lies precisely in those laws of physics. Dr. White and other physicists have found loopholes in some mathematical equations—loopholes that indicate that warping the space-time fabric is indeed possible.

Working at NASA Eagleworks —a skunkworks operation deep at NASA's Johnson Space Center—Dr. White's team is trying to find proof of those loopholes. They have "initiated an interferometer test bed that will try to generate and detect a microscopic instance of a little warp bubble" using an instrument called the White-Juday Warp Field Interferometer.

It may sound like a small thing now, but the implications of the research huge. In his own words:

Although this is just a tiny instance of the phenomena, it will be existence proof for the idea of perturbing space time-a "Chicago pile" moment, as it were. Recall that December of 1942 saw the first demonstration of a controlled nuclear reaction that generated a whopping half watt. This existence proof was followed by the activation of a ~ four megawatt reactor in November of 1943. Existence proof for the practical application of a scientific idea can be a tipping point for technology development.

By creating one of these warp bubbles, the spaceship's engine will compress the space ahead and expand the space behind, moving it to another place without actually moving, and carrying none of the adverse effects of other travel methods. According to Dr. White, "by harnessing the physics of cosmic inflation, future spaceships crafted to satisfy the laws of these mathematical equations may actually be able to get somewhere unthinkably fast—and without adverse effects."

He says that, if everything is confirmed in these practical experiments, we would be able to create an engine that will get us to Alpha Centauri "in two weeks as measured by clocks here on Earth." The time will be the same in the spaceship and on Earth, he claims, and there will not be "tidal forces inside the bubble, no undue issues, and the proper acceleration is zero. When you turn the field on, everybody doesn't go slamming against the bulkhead, which would be a very short and sad trip."

The energy problem, solved

There was only one problem with all this: where does the energy come from? While we knew that warp drives were theoretically possible, physicists have always argued that they would require a ball of exotic matter the size of Jupiter to power it. Clearly, that was not practical. But thankfully, Dr. White has found a solution that changes the game completely.

The Eagleworks team has discovered that the energy requirements are much lower than previously thought. If they optimize the warp bubble thickness and "oscillate its intensity to reduce the stiffness of space time," they would be able to reduce the amount of fuel to manageable amount: instead of a Jupiter-sized ball of exotic matter, you will only need 500 kilograms to "send a 10-meter bubble (32.8 feet) at an effective velocity of 10c."

Ten c! That's ten times the speed of light, people (remember, the ship itself would not go faster than the speed of light. But effectively it will seem like it does).

That means that we would be able to visit Gliese 581g —a planet similar to Earth 20 light years away from our planet—in two years . Two years is nothing. It took Magellan three years to circumnavigate around our home planet—from August 1519 to September 1522. A four year roundtrip to see a planet like Earth is completely doable. And there are even closer destinations where we can send robots or astronauts.

The important thing is that there is now a door open to a different kind of exploration. That, like Dr. White says, "perhaps a Star Trek experience within our lifetime is not such a remote possibility." We may be witnessing the very beginning of a new age of space exploration , one that would finally take us from our pale blue dot back to where we belong .

I don't know about you, but I'm more excited than when Captain Kirk got his first unobtonanium underpants.

So yeah, I am really excited for Interstellar

I keep reminding myself not to build up my expectations because I may get disappointed, but I can't. This movie is going to be scary and exciting. Scary because this future may be around the corner and we may not find a solution in time. And exciting because this may be the first science fiction movie that shows interstellar travel in a plausible way.

How interstellar travel is part of the solution to our problems, I have no clue whatsoever. We will have to wait to see.

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Warp Drives: New Hope for Interstellar Travel

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From the works of Isaac Asimov to Star Trek and Star Wars, science fiction presents alternative realities wherein space-faring civilizations travel throughout the universe. Unfettered by present technology, these stories often describe faster than light travel as being key for civilizations to reach the stars.

Sci-fi can become depressing if taken as a dream for a far-fetched tomorrow that will never come. However, the magic of physics and engineering gives us the chance to realize through technology what was once solely fantasy.

In the scientific community, hope for unlocking faster than light travel often rests upon building so-called warp drives.

In September of 2020, a new paper on this technology was published in Classical and Quantum Gravity by researchers Erik Lentz, Alexey Bobrick, and Gianni Martire from the Advanced Propulsion Laboratory at Applied Physics in New York City.

Titled “Introducing Physical Warp Drives”, they present what they believe to be a new foundation for actualizing warp drive technology that can be realized without disobeying present day physics.

What is a Warp Drive?

Mentioned in many science fiction worlds, warp drives are technology harnessed by spacecraft which would allow faster than light – a.k.a. superluminal – travel by ‘warping’ or deforming space-time.

This is why scientists now argue that during the early phase of the Big Bang the universe was able to expand faster than the speed of light.

One great misunderstanding of Einstein’s theory is the assumption that it prevents faster than light travel. The conundrum is crossing the barrier of light speed not being above it.

The defense for warp drive technology lies in the inherent quality of the craft manipulating space-time around itself to create motion – rather than attempting to accelerate through space-time.

In addition, there is nothing inherent to warp drives that requires them to have superluminal speeds. One could take a step back and simply argue for the possibility of ‘sub-luminal’ warp drives.

Improving the Alcubierre Drive

In the paper’s abstract, the researchers claim that they “present the first general model for subliminal positive-energy, spherically symmetric warp drives,” by demonstrating:

“that any warp drive, including the Alcubierre drive, is a shell of regular or exotic material moving inertially with a certain velocity. Therefore, any warp drive requires propulsion. We show that a class of subluminal, spherically symmetric warp drive spacetimes, at least in principle, can be constructed based on the physical principles known to humanity today.”

In order to comprehend the problem their paper attempts to solve, one must understand the Alcubierre drive.

Based on conclusions drawn from Einstein’s field equations in general relativity, the Alcubierre drive is a theoretical warp drive which functions by contracting space-time in front of the vehicle and expanding space-time from behind – theoretically generating motion and moving one forward.

However, his math equations require a huge amount of theoretical negative energy – which currently does not exist.

In his paper titled “The warp drive: hyper-fast travel within general relativity” published in General Relativity and Quantum Cosmology, Alcubierre states that:

“By a purely local expansion of spacetime behind the spaceship and an opposite contraction in front of it, motion faster than the speed of light as seen by observers

outside the disturbed region is possible […] The resulting distortion is reminiscent of the ‘warp drive’ of science fiction. However, just as it happens with wormholes, exotic matter will be needed in order to generate a distortion of spacetime.”

Speaking to Nature World News, Bobrick comments that “most people in the field of science are aware of the Alcubierre Drive and assume that warp drives are unphysical because they require negative energy, […] However, this is no longer the case.” He claims that he “followed a different course than NASA and others, and our study has shown that there are many other classes of warp drives in general relativity, […] In fact, we’ve created new forms of warp drive solutions that don’t need negative energy and, as a result, are physical.”

In their paper, the researchers suggest that a few changes to the Alcubierre drive could make it function without relying upon negative energy.

However, the new proposed technology would be different from the Alcubierre Drive in that it could only go as fast as the speed of light – losing the ability to exceed it.

According to their research, a key distinction between Alcubierre’s notions and their own is that rather than using “negative energy” – a substance which does not exist in the universe – “bubbles” of spacetime could be used to make the drive possible.

This ‘bubble’ created by the geometry of a warp drive would encase an inside region which the researchers call the “passenger area.” In this zone space-time would be flat, meaning that there are no gravitational forces.

Outside the passenger area lies the “wall” of the craft, needing to be made of a suitable material to surround and protect the passengers.

In the outside region beyond the wall is the gravitational field of the warp drive – where the exotic physics would need to function. This field would manipulate space-time and have a teardrop shape, teetering off behind the spaceship where there would be flat, unaltered space-time.

Because physics prohibit the bodies of the passengers breaking the lightspeed barrier, the passage of time and motion of space inside the passenger area would differ from the outside environment.

The researchers believe another upgrade from the Alcubierre drive lies in the dimensions of the craft – as the energy required is related to its shape. They believe that by sitting passengers next to each other rather than behind each other results in a more efficient model.

Having provided the physics-friendly blueprints for a warp drive, Lentz states that:

“The next step is to figure out how to bring down the astronomical amount of energy needed to within the range of today’s technologies, such as a large modern nuclear fission power plant. Then we can talk about building the first prototypes.”

A Ticket to the Stars

When the first functioning prototype is built, then what? Where should or could we go?

Well, Proxima Centauri – the nearest star to our solar system – might be a safe bet.

300,000 times the distance from the Earth to the Sun, Proxima Centauri sits approximately 4.25 light years away. Speaking to Reuters, Lentz explains that the 25 trillion-mile journey “would take about 50,000 to 70,000 years to reach […] and nuclear propulsion with proposed technology would get there in about 100 years, [but] a light speed trip would take four years and three months.”

Lentz believes humanity must go big or go home by thinking daringly, arguing that “if we are limited to traveling at sub-light speed, then multi-generational spaceships must be used for destinations beyond the nearest stars, which is basically a glorified burial casket for at least the first generation of people. I do not find that prospect nearly as inspiring.

Author: Liam Penn ( Dark Matters)

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What Is Star Trek: Discovery's Spore Drive and How Does It Work?

The spore drive on Star Trek: Discovery is the universe's most fantastical technology that works in the show but should never replace warp engines.

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How does the spore drive work in star trek, why the uss discovery is the only starfleet ship with a spore drive, is the spore drive faster than warp speed, why star trek should probably stop using the spore drive.

With Season 5, Star Trek: Discovery embarks on the final mission for its dynamic crew and one-of-a-kind starship. There are many things about this series that diverged from past series or films in the universe created by Gene Roddenberry six decades ago. How the spore drive that powers the USS Discovery works is perhaps the most fanciful concept in Star Trek . When piloted by Ripper the "space tardigrade," Lieutenant Paul Stamets or Kewijan empath Cleveland Booker, this organic propulsion system is one of the most powerful technologies in all science fiction and fantasy.Despite the universe's reputation for somewhat grounded science-fiction, the displacement-activated spore hub drive is squarely in the realm of fantasy. This is not new territory for Star Trek , however.

Vulcan mind-melds, the concept of "subspace" and Star Trek's ubiquitous transporters are all, to varying degrees, magical nonsense. What helps sell these far-out technologies to skeptical audiences is the (lovingly named) technobabble that accompanies them. Vulcans use innate psychic abilities to connect to another consciousness like file-sharing over wifi. Transporters break people down into atoms and beam them to another physical location, where they are reassembled just as they were. Subspace allows communications to travel faster than speed of light, as well as any number of anomalies that create workarounds to the immutable laws of physics. USS Discovery's spore drive is equally able to break the laws of physics and travel on a "mycelial network" that exists outside of regular spacetime .

'Bittersweet and Shocking': Star Trek: Discovery Star Addresses the Series Getting Canceled

Former Star Trek: Voyager producer Bryan Fuller was tapped to bring the universe back to television, and he co-created the series with Alex Kurtzman. He left early in pre-production, but many of the concepts he introduced remained, such as the controversial Klingon redesign . The spore drive was one such concept, which drew from the research and philosophy of real-world mycologist Paul Stamets. This is why Anthony Rapp's character has that name, after all.

Next to engineering, the USS Discovery has a room where Lieutenant Stamets grows the spores needed to power the drive. He created it with his friend Straal, and Starfleet "co-opted" the technology once the Klingon-Federation War broke out. It was Straal who figured out the spore drive needed a pilot with compatible DNA to pilot the ship. He used a creature which Michael Burnham called a "tardigrade." Eventually, Stamets injected himself with tardigrade DNA which made him the only person capable of successfully using the spore drive. Later, Cleveland Booker was also able to serve as a navigator because of his natural empathic abilities.

Through their connection to the spores, the navigator is able to pilot the ship using invisible connections on a galactic mycelial network. In Star Trek: Discovery this network is represented much like the Quantum Realm in the Marvel Cinematic Universe . Like the Avengers, the ship is able to travel through this lower dimension and emerge in real space anywhere. However, the network the ship can travel on is limited to the Milky Way galaxy. Put another way, the spore drive allows the USS Discovery to teleport anywhere in the galaxy in an instant.

Star Trek: Discovery's Mary Wiseman, Wilson Cruz and Blu del Barrio Hype Finale

Despite existing a decade before the time of Star Trek: The Original Series , the USS Discovery was a bleeding-edge scientific vessel before the war. Once the USS Glenn and Straal were killed in their accident, Lieutenant Stamets became the only person in the universe to understand how the spore drive worked. While he sent his designs to Starfleet, none of their scientists could get it to work. Once the ship time-traveled to the 32nd Century, Starfleet was able to build a working prototype, but it was destroyed when it was stolen by Booker in Season 4 .

Even if Starfleet's scientists and engineers were able to replicate the machinery that made the spore drive function, they still lacked a crucial element: a navigator. Without the tardigrade or a compatible human, the spore drive could only safely travel a few hundred kilometers. Stamets can only serve as the navigator because of the tardigrade DNA he injected into himself. Since the creatures are sentient, difficult to catch and the Federation is against genetic modification, no one else can use his method. Booker's natural empathic abilities allowed him to serve as navigator, but his gifts are unique to Kwejian, which was destroyed in Season 4 .

In the first episode of Star Trek: Discovery Season 5 , Stamets is depressed because Starfleet has abandoned its efforts to recreate his technology. He wanted the spore drive to be his legacy. Instead, Starfleet and the Federation committed to a technology called the "pathway drive," an unknown method of faster-than-light travel that doesn't require dilithium crystals like warp engines. This means that the USS Discovery will be the only serviceable Starfleet vessel capable of traveling via the mycelial network, at least so long as Stamets or Booker are willing to serve as navigator.

How Star Trek: Discovery Season 5 Connects to TNG's Biggest Open Mystery

While it's natural to compare the spore drive to Star Trek 's famous warp drive, the USS Discovery isn't traveling at speed when it jumps. In fact, it's closer to Star Wars ' hyperspace , a dimension that exists underneath spacetime. Yet, unlike the Millennium Falcon, the USS Discovery is able to enter and exist the mycelial network in mere seconds. Ships traveling through hyperspace still take time to get from one point to another. The USS Discovery's spore drive flies through the network far faster than warp drive, but it's a completely different method of travel .

Of all the sci-fi Star Trek inventions, warp drive is one of the more plausible ones. Einstein's Theory of General Relativity established that the speed of light is as fast as anything can go through space, but not how fast spacetime itself can go. Thus, while Starfleet vessels travel faster than light, they do it by slipping through a loophole in the laws of physics. Warp engines create a bubble that bends spacetime itself. The ships ride it like a wave and are able to go faster than Einstein's universal speed limit. However, with the spore drive, the USS Discovery is able to just pop out of reality and emerge at a different physical location in the galaxy.

While there are some actual scientific concepts behind both the spore and warp drives, the latter is far more sound . Physical travel via the mycelial network is as plausible as trying to use tree roots as a subway. Still, even though the math works for warp drive, there are countless other effects that would make traveling at those speeds unsurvivable. This is why bridge and engineering officers in Star Trek are always talking about "inertial dampers." Similarly, travel via the mycelial network is not without risk, specifically from "Hawking radiation." This theoretical energy somehow turned the crew of the USS Glenn inside out after a test jump in Season 1, Episode 3, "Context is for Kings."

Star Trek: Discovery Wasn't Originally Going to End With Season 5, Reveals EP

All science fiction requires some level of suspension of disbelief, and there are many technologies in Star Trek that are just as magical as the spore drive. Still, the concept was met with a lot of criticism from fans that goes beyond the typical reluctance to embrace new iterations of this universe. "Although physically implausible, warp drive isn't laughably ridiculous. The [spore] drive is, " scientist Steven Sazlberg wrote for Forbes . Of course, Star Trek is full of ridiculous concepts like Thomas Riker, Will Riker's "transporter clone. " The fantastical nature of the spore drive isn't why it should stay on the USS Discovery.

The USS Voyager-J was revealed to be the first ship set to test the new pathway drive, whatever it is. However, if the spore drive existed and worked in the 24th Century, the original USS Voyager could've used it to get back from the Delta Quadrant before Captain Janeway's coffee got cold . Everything about the USS Discovery was classified at the end of the show's second season, which explains why the spore drive was never even considered as a means to rescue the USS Voyager. They also lacked a compatible navigator. But more importantly, the spore drive would have made the seven seasons of Star Trek: Voyager unnecessary.

The spore drive is a fun conceit for Star Trek: Discovery , but in truth it is simply too powerful a technology. The purpose of Starfleet is, after all, to explore the unknown. If every vessel in every Star Trek universe had a spore drive, at least 500 of its 900 total episodes wouldn't have happened. That Stamets is the only person truly able to crack this technology also speaks to the unique nature of humanity. Even with all of Starfleet's brilliance, there is an irreplaceable human contribution to make its most magical technology work.

Star Trek: Discovery debuts new episodes Thursdays on Paramount+.

Star Trek: Discovery

Screen Rant

Voyager is why star trek is replacing discovery’s spore drive.

Starfleet is abandoning the spore drive in Star Trek: Discovery season 5, having found a better form of warp travel thanks to the USS Voyager.

WARNING: Contains SPOILERS for Star Trek: Discovery season 5, episode 1, "Red Directive"

• Star Trek: Discovery Season 5 bids farewell to the spore drive, as USS Voyager's pathway drive takes over in the 32nd century.
• Commander Stamets reveals Starfleet's decision to halt spore drive development, making Discovery unique in the Star Trek franchise.
• The USS Voyager-J's pathway drive paves the way for safer and sustainable warp travel in Star Trek's future.

The 32nd century's version of the USS Voyager is the reason that Star Trek: Discovery season 5 is abandoning Starfleet's revolutionary spore drive technology. Since they arrived in the 32nd century in season 3, the USS Discovery crew's one-of-a-kind spore drive has represented a potential replacement for dilithium-reliant warp travel in Star Trek 's future . However, various obstacles, most notably rogue Risan scientist Dr. Ruon Tarka (Shawn Doyle) and his theft of the only working prototype have prevented the spore drive from being rolled out.

In Star Trek: Discovery season 5, episode 1 , "Red Directive", Commander Paul Stamets (Anthony Rapp) reveals that Starfleet has shuttered further development on the spore drive . Starfleet's decision means that the USS Discovery will remain one-of-a-kind, making season 5 the last outing for Starfleet's spore drive. Instead of taking Discovery's spore drive further, Starfleet are instead forging ahead with the new pathway drive, first trialed by the USS Voyager-J in Star Trek: Discovery season 4 .

Star Trek Is Ditching Discovery's Spore Drive - And That's Good!

Uss voyager is why star trek is quitting discovery’s spore drive, voyager has a history of scientific advancement in starfleet..

In Star Trek: Discovery 's season 4 premiere, "Kobayashi Maru", it was revealed that the USS Voyager-J had been newly fitted with a protoype pathway drive . Federation President Laira Rillak (Chelah Horsdal) was looking for the right captain to command the ship and test out this new technology. Now, Discovery 's season 5 premiere, "Red Directive" reveals that those tests were successful, leading to the pathway drive being the new standard for future Starfleet ships. The rollout is still in the early stages, however, as Captain Rayner (Callum Keith Rennie) states that his ship, the USS Antares, doesn't have a pathway drive fitted.

Captain Michael Burnham (Sonequa Martin-Green) was under consideration to command the USS Voyager-J, but President Rillak didn't believe that she was ready.

It feels appropriate that the USS Voyager is responsible for replacing Star Trek: Discovery 's spore drive, given its namesake's impact on warp travel centuries earlier . Star Trek: Prodigy revealed that, after returning to the Alpha Quadrant, much of the technology the USS Voyager encountered in the Delta Quadrant was adapted by Starfleet. For example, the USS Dauntless, commanded by Vice Admiral Kathryn Janeway (Kate Mulgrew) had a quantum slipstream drive fitted, first encountered in Star Trek: Voyager 's season 4 finale, "Hope and Fear".

10 Ways USS Voyager Changed In Star Trek’s Delta Quadrant

When will we see star trek: discovery's pathway drive in action.

As the USS Discovery is in the middle of a vitally important mission to find the Progenitors' technology to create life, it doesn't seem like there will be much time for a refit. Therefore, it's unlikely that Discovery will be using the pathway drive at any point in Star Trek: Discovery season 5. It's certainly possible that Captain Burnham could receive assistance from a starship like the USS Voyager-J at some later point in Discovery season 5, but it's also possible that the pathway drive was just a tease of things to come in the now- canceled Star Trek: Discovery season 6 .

As it will focus on a batch of new recruits, the Starfleet Academy show feels like an ideal way to reveal more about the pathway drive.

Star Trek: Starfleet Academy will pick up the baton in the 32nd century, however, making it the most likely candidate for a pathway drive demonstration . As it will focus on a batch of new recruits, the Starfleet Academy show feels like an ideal way to reveal more about the pathway drive. As the cadets learn how a pathway drive works, and how it differs from a more traditional warp drive, so too will Star Trek fans who tune into the YA-oriented show. Starfleet Academy leading the way with a new warp drive replacement would be a fitting way to continue the legacy of Star Trek: Discovery and its spore drive.

Star Trek: Starfleet Academy is looking to begin production in late summer 2024.

Star Trek: Starfleet Academy

After being closed for over a hundred years, Starfleet Academy is reopening its doors to those who wish to pursue a career as Starfleet Officers. Star Trek: Starfleet Academy will follow a new group of cadets as they come of age, and build friendships, rivalries, and romantic relationships while being threatened by a new adversary that could destroy the Academy and the Federation itself.

Why Star Trek Keeping Standard Warp Travel Is Best

The specifics of how the pathway drive works are still a mystery in Star Trek: Discovery season 5, but it's presumably rooted in traditional warp travel. The spore drive was an incredibly complicated method of travel that required specific calculations and a willing host to navigate the mycelial network . In "Red Directive", Stamets states that, with more time, he could have worked out the issues with navigation, but never got the chance. The grisly fate of the USS Glenn in Discovery season 1 revealed that the slightest miscalculation in spore drive navigation could have devastating consequences for the crew.

Presumably, the pathway drive is a means to achieve warp travel while using less dilithium, to reduce the Federation's reliance on it following the scarcity caused by the Burn. This is therefore a less risky proposition, which will be why Starfleet are now rolling it out following the USS Voyager-J's successful trial. While it may be disappointing for Stamets in Star Trek: Discovery , the pathway drive's potential to make warp travel safer and more sustainable should be something to celebrate.

Star Trek: Discovery streams Thursdays on Paramount+.

Star Trek: Prodigy season 1 is streaming on Netflix.

Star Trek: Discovery

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Star Trek: Discovery is an entry in the legendary Sci-Fi franchise, set ten years before the original Star Trek series events. The show centers around Commander Michael Burnham, assigned to the USS Discovery, where the crew attempts to prevent a Klingon war while traveling through the vast reaches of space.

Star Trek Voyager

The fifth entry in the Star Trek franchise, Star Trek: Voyager, is a sci-fi series that sees the crew of the USS Voyager on a long journey back to their home after finding themselves stranded at the far ends of the Milky Way Galaxy. Led by Captain Kathryn Janeway, the series follows the crew as they embark through truly uncharted areas of space, with new species, friends, foes, and mysteries to solve as they wrestle with the politics of a crew in a situation they've never faced before.

Star Trek: Prodigy

Star Trek: Prodigy is the first TV series in the Star Trek franchise marketed toward children, and one of the few animated series in the franchise. The story follows a group of young aliens who find a stolen Starfleet ship and use it to escape from the Tars Lamora prison colony where they are all held captive. Working together with the help of a holographic Captain Kathryn Janeway (Kate Mulgrew), the new crew of the USS Protostar must find their way back to the Alpha Quadrant to warn the Federation of the deadly threat that is pursuing them.

News from the Columbia Climate School

Was It an Alien Spacecraft—Or a Delivery Truck?

Kevin Krajick

On Jan. 8, 2014, a meteor raced through Earth’s atmosphere off Papua New Guinea, exploded into a fireball over the ocean, and disappeared. That would have been the end of it. Except for Harvard astronomer Abraham “Avi” Loeb , who in 2019 analyzed data from low-frequency sound sensors run by the U.S. Department of Defense capable of detecting the tracks of meteors. Based on the object’s apparently unusual trajectory and immense speed, Loeb and colleagues concluded it was the first documented object from outside the solar system to encounter the Earth. They dubbed it IM1, the “I” standing for “Interstellar.”

Most meteors vaporize in the air; solid fragments that reach the ground, known as meteorites, are rare. But finding anything from IM1 could be scientific coup. Loeb, a sometimes controversial scientific superstar and best-selling author of a book about the search for extraterrestrial life, went to work organizing a search expedition.

One problem: the record of the airborne shock wave left room for a wide margin of error regarding where anything may have fallen into the ocean―an area of some 120 square kilometers. To help refine the data, the group turned to an earthquake seismometer at a naval base on the Papua New Guinea island of Manus, the nearest land. In its records, they found an earthquake signal matching the time of the meteor―an apparent quivering of the Earth’s surface as the airborne wave hit. Bolstered by this, they zeroed in on a 16-kilometer-square strip of seabed about 50 miles north of the island.

In June 2023, Loeb’s team scoured the ocean bottom with powerful magnets towed under a ship. They found no meteorites, but did dredge up some 700 spherules―tiny droplets solidified from molten material, which sometimes rain down when a meteor burns up. Not only that— they said some spherules had ratios of elements not found on Earth or any other planet in the solar system. And even more than that: “Another possibility is that this unfamiliar abundance pattern may reflect an extraterrestrial technological origin”― as Loeb and others speculated , bits of an alien spacecraft.

While even the U.S. Space Command agreed the object was probably interstellar, many scientists doubted that Loeb had really found its remnants, much less that it was something made by aliens. Among them: a group of planetary scientists led by Benjamin Fernando of Johns Hopkins University. They decided to look into not the spherules themselves, but the earthquake record. For this, they recruited Göran Ekström , a seismologist at Columbia University’s Lamont-Doherty Earth Observatory known for studying unusual seismic events .

The group reported their results at the March Lunar and Planetary Science Conference. And a ruckus ensued in the scientific community and in media .

In the seismic station’s records, Ekström found the purported meteor-inspired signal right where it was supposed to be. Then he looked further and found that the records contained hundreds of other tremors in the weeks before and after, and many of them looked similar to that of the meteor. They were not characteristic of the small earthquakes that commonly shake this region, located on the Pacific Ring of Fire, where tectonic plates are constantly rubbing shoulders.

The signals consisted of so-called Rayleigh waves, high-frequency motions that travel on or just under the surface, and die out quickly as they radiate from their source. These can be generated by earthquakes, but also by human activities, including explosions, electrical signals and vehicles. The sources of these ones seemed to be moving, not stationary. Moreover, they appeared in a definite pattern: several per hour, almost invariably between 5am and 11pm local time.

The team checked a Google Earth map showing the seismometer and its environs. It was just off the main road to the harbor, near the Manus Navy Health Center. The center seemed to be a locus of activity, with the signals moving back and forth from it, southwest to north―the same orientation as the road. Ekström’s conclusion: the seismicity was coming from trucks bumping along the irregular surface of the road, mostly in daytime, stopping at the health center to deliver or pick up people or supplies, then going back where they came from. That included the purported tremor from the meteor explosion.

“The signal Harvard used to locate the impact is totally bogus,” said Ekström. “There’s a rich literature on the kind of seismicity produced by vehicles. When you drive along a bumpy road, you’re generating waves that have all the characteristics of the ones we saw.” The clincher, he said: the daily ebb and flow of the signals. “Meteors, earthquakes, landslides, whatever natural phenomena, they don’t watch the clock. People do.”

The team also reanalyzed the airborne sound waves, and identified what they say is a more likely location for the meteor to have blown up, some 100 miles north of the Harvard search area. “The fireball location was actually very far away from where the oceanographic expedition went to retrieve these meteor fragments,” said Fernando in a press release . “Not only did they use the wrong signal, they were looking in the wrong place.” The group argues that the recovered spherules are probably remnants of ordinary meteorites, possibly mixed with contaminants from the Earth. “We strongly suspect it wasn’t aliens,” Fernando added.

Loeb quickly struck back. Pointing out that Fernando’s team had yet to publish their results in a peer-reviewed journal, he wrote a rebuttal on the popular website Medium and another on the scientific site arXiv . He said his team had primarily used the airborne sound data, and would have searched basically the same area with or without the seismic data. He told the Washington Post that the critics “did not collect material, they did not analyze anything. They just sit on their chairs and express their opinions.” Loeb said that when he gets enough funding, he will resume the search for fragments.

As a result of the seismic study, Loeb was widely razzed by media including The New York Times . But some scientists told Scientific American that even if the material was not interstellar, the search could produce useful science. Eleanor Sansom , a planetary scientist at Australia’s Curtin University and coauthor of the seismic study, said that tracking incoming meteors is a fledgling field. “Trying to work out how things come through our atmosphere, where they’re coming from and where they’re going to land is really exciting,” she said.

“They should have talked to a seismologist the first time,” said Ekström. That said, he added, “People love this stuff, everything about aliens and meteors and meteorites. If they do go back, I hope they find something interesting.”

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The Moscow Metro Museum of Art: 10 Must-See Stations

There are few times one can claim having been on the subway all afternoon and loving it, but the Moscow Metro provides just that opportunity.  While many cities boast famous public transport systems—New York’s subway, London’s underground, San Salvador’s chicken buses—few warrant hours of exploration.  Moscow is different: Take one ride on the Metro, and you’ll find out that this network of railways can be so much more than point A to B drudgery.

The Metro began operating in 1935 with just thirteen stations, covering less than seven miles, but it has since grown into the world’s third busiest transit system ( Tokyo is first ), spanning about 200 miles and offering over 180 stops along the way.  The construction of the Metro began under Joseph Stalin’s command, and being one of the USSR’s most ambitious building projects, the iron-fisted leader instructed designers to create a place full of svet (radiance) and svetloe budushchee (a radiant future), a palace for the people and a tribute to the Mother nation.

Consequently, the Metro is among the most memorable attractions in Moscow.  The stations provide a unique collection of public art, comparable to anything the city’s galleries have to offer and providing a sense of the Soviet era, which is absent from the State National History Museum.  Even better, touring the Metro delivers palpable, experiential moments, which many of us don’t get standing in front of painting or a case of coins.

Though tours are available , discovering the Moscow Metro on your own provides a much more comprehensive, truer experience, something much less sterile than following a guide.  What better place is there to see the “real” Moscow than on mass transit: A few hours will expose you to characters and caricatures you’ll be hard-pressed to find dining near the Bolshoi Theater.  You become part of the attraction, hear it in the screech of the train, feel it as hurried commuters brush by: The Metro sucks you beneath the city and churns you into the mix.

With the recommendations of our born-and-bred Muscovite students, my wife Emma and I have just taken a self-guided tour of what some locals consider the top ten stations of the Moscow Metro. What most satisfied me about our Metro tour was the sense of adventure .  I loved following our route on the maps of the wagon walls as we circled the city, plotting out the course to the subsequent stops; having the weird sensation of being underground for nearly four hours; and discovering the next cavern of treasures, playing Indiana Jones for the afternoon, piecing together fragments of Russia’s mysterious history.  It’s the ultimate interactive museum.

Top Ten Stations (In order of appearance)

Kievskaya station.

Kievskaya Station went public in March of 1937, the rails between it and Park Kultury Station being the first to cross the Moscow River.  Kievskaya is full of mosaics depicting aristocratic scenes of Russian life, with great cameo appearances by Lenin, Trotsky, and Stalin.  Each work has a Cyrillic title/explanation etched in the marble beneath it; however, if your Russian is rusty, you can just appreciate seeing familiar revolutionary dates like 1905 ( the Russian Revolution ) and 1917 ( the October Revolution ).

Mayakovskaya Station

Mayakovskaya Station ranks in my top three most notable Metro stations. Mayakovskaya just feels right, done Art Deco but no sense of gaudiness or pretention.  The arches are adorned with rounded chrome piping and create feeling of being in a jukebox, but the roof’s expansive mosaics of the sky are the real showstopper.  Subjects cleverly range from looking up at a high jumper, workers atop a building, spires of Orthodox cathedrals, to nimble aircraft humming by, a fleet of prop planes spelling out CCCP in the bluest of skies.

Novoslobodskaya Station

Novoslobodskaya is the Metro’s unique stained glass station.  Each column has its own distinctive panels of colorful glass, most of them with a floral theme, some of them capturing the odd sailor, musician, artist, gardener, or stenographer in action.  The glass is framed in Art Deco metalwork, and there is the lovely aspect of discovering panels in the less frequented haunches of the hall (on the trackside, between the incoming staircases).  Novosblod is, I’ve been told, the favorite amongst out-of-town visitors.

Komsomolskaya Station

Komsomolskaya Station is one of palatial grandeur.  It seems both magnificent and obligatory, like the presidential palace of a colonial city.  The yellow ceiling has leafy, white concrete garland and a series of golden military mosaics accenting the tile mosaics of glorified Russian life.  Switching lines here, the hallway has an Alice-in-Wonderland feel, impossibly long with decorative tile walls, culminating in a very old station left in a remarkable state of disrepair, offering a really tangible glimpse behind the palace walls.

Dostoevskaya Station

Dostoevskaya is a tribute to the late, great hero of Russian literature .  The station at first glance seems bare and unimpressive, a stark marble platform without a whiff of reassembled chips of tile.  However, two columns have eerie stone inlay collages of scenes from Dostoevsky’s work, including The Idiot , The Brothers Karamazov , and Crime and Punishment.   Then, standing at the center of the platform, the marble creates a kaleidoscope of reflections.  At the entrance, there is a large, inlay portrait of the author.

Chkalovskaya Station

Chkalovskaya does space Art Deco style (yet again).  Chrome borders all.  Passageways with curvy overhangs create the illusion of walking through the belly of a chic, new-age spacecraft.  There are two (kos)mosaics, one at each end, with planetary subjects.  Transferring here brings you above ground, where some rather elaborate metalwork is on display.  By name similarity only, I’d expected Komsolskaya Station to deliver some kosmonaut décor; instead, it was Chkalovskaya that took us up to the space station.

Elektrozavodskaya Station

Elektrozavodskaya is full of marble reliefs of workers, men and women, laboring through the different stages of industry.  The superhuman figures are round with muscles, Hollywood fit, and seemingly undeterred by each Herculean task they respectively perform.  The station is chocked with brass, from hammer and sickle light fixtures to beautiful, angular framework up the innards of the columns.  The station’s art pieces are less clever or extravagant than others, but identifying the different stages of industry is entertaining.

Baumanskaya Statio

Baumanskaya Station is the only stop that wasn’t suggested by the students.  Pulling in, the network of statues was just too enticing: Out of half-circle depressions in the platform’s columns, the USSR’s proud and powerful labor force again flaunts its success.  Pilots, blacksmiths, politicians, and artists have all congregated, posing amongst more Art Deco framing.  At the far end, a massive Soviet flag dons the face of Lenin and banners for ’05, ’17, and ‘45.  Standing in front of the flag, you can play with the echoing roof.

Ploshchad Revolutsii Station

Novokuznetskaya Station

Novokuznetskaya Station finishes off this tour, more or less, where it started: beautiful mosaics.  This station recalls the skyward-facing pieces from Mayakovskaya (Station #2), only with a little larger pictures in a more cramped, very trafficked area.  Due to a line of street lamps in the center of the platform, it has the atmosphere of a bustling market.  The more inventive sky scenes include a man on a ladder, women picking fruit, and a tank-dozer being craned in.  The station’s also has a handsome black-and-white stone mural.

Here is a map and a brief description of our route:

Start at (1)Kievskaya on the “ring line” (look for the squares at the bottom of the platform signs to help you navigate—the ring line is #5, brown line) and go north to Belorusskaya, make a quick switch to the Dark Green/#2 line, and go south one stop to (2)Mayakovskaya.  Backtrack to the ring line—Brown/#5—and continue north, getting off at (3)Novosblodskaya and (4)Komsolskaya.  At Komsolskaya Station, transfer to the Red/#1 line, go south for two stops to Chistye Prudy, and get on the Light Green/#10 line going north.  Take a look at (5)Dostoevskaya Station on the northern segment of Light Green/#10 line then change directions and head south to (6)Chkalovskaya, which offers a transfer to the Dark Blue/#3 line, going west, away from the city center.  Have a look (7)Elektroskaya Station before backtracking into the center of Moscow, stopping off at (8)Baumskaya, getting off the Dark Blue/#3 line at (9)Ploschad Revolyutsii.  Change to the Dark Green/#2 line and go south one stop to see (10)Novokuznetskaya Station.

Check out our new Moscow Indie Travel Guide , book a flight to Moscow and read 10 Bars with Views Worth Blowing the Budget For

Jonathon Engels, formerly a patron saint of misadventure, has been stumbling his way across cultural borders since 2005 and is currently volunteering in the mountains outside of Antigua, Guatemala.  For more of his work, visit his website and blog .

Photo credits:   SergeyRod , all others courtesy of the author and may not be used without permission