radio waves travel through empty space

• school Campus Bookshelves
• menu_book Bookshelves
• perm_media Learning Objects
• login Login
• how_to_reg Request Instructor Account
• hub Instructor Commons
• Download Page (PDF)
• Download Full Book (PDF)
• Periodic Table
• Physics Constants
• Scientific Calculator
• Reference & Cite
• Tools expand_more
• Readability

selected template will load here

This action is not available.

23.2: Electromagnetic Waves and their Properties

• Last updated
• Save as PDF
• Page ID 15712

learning objectives

• Explain the meaning and importance of Maxwell’s equations

Maxwell’s Equations

Maxwell’s equations are a set of four partial differential equations that, along with the Lorentz force law, form the foundation of classical electrodynamics, classical optics, and electric circuits.

Named after esteemed physicist James Clerk Maxwell, the equations describe the creation and propagation of electric and magnetic fields. Fundamentally, they describe how electric charges and currents create electric and magnetic fields, and how they affect each other.

Maxwell’s equations can be divided into two major subsets. The first two, Gauss’s law and Gauss’s law for magnetism, describe how fields emanate from charges and magnets respectively. The other two, Faraday’s law and Ampere’s law with Maxwell’s correction, describe how induced electric and magnetic fields circulate around their respective sources.

Each of Maxwell’s equations can be looked at from the “microscopic” perspective, which deals with total charge and total current, and the “macroscopic” set, which defines two new auxiliary fields that allow one to perform calculations without knowing microscopic data like atomic-level charges.

Gauss’s Law

Gauss’s law relates an electric field to the charge(s) that create(s) it. The field (E) points towards negative charges and away from positive charges, and from the microscopic perspective, is related to charge density (ρ) and vaccuum permittivity (ε 0 , or permittivity of free space) as:

\[\nabla \cdot \mathbf { E } = \dfrac { \rho } { \epsilon _ { 0 } }\]

Gauss’s Law basically says that a net amount of charge contained within a region of space will generate an electric field that emanates through the surface that surrounds that region.

Example of Gauss’s Law : A positive charge contained within a region of space creates an electric field that emanates from the surface of that region.

Gauss’s Law for Magnetism

Gauss’s law for magnetism states that there are no “magnetic charges (or monopoles)” analogous to electric charges, and that magnetic fields are instead generated by magnetic dipoles . Such dipoles can be represented as loops of current, but in many ways are similar in appearance to positive and negative “magnetic charges” that are inseparable and thus have no formal net “magnetic charge.”

Magnetic field lines form loops such that all field lines that go into an object leave it at some point. Thus, the total magnetic flux through a surface surrounding a magnetic dipole is always zero.

Field lines caused by a magnetic dipole : The field lines created by this magnetic dipole either form loops or extend infinitely.

The differential form of Gauss’s law for magnetic for magnetism is

\[\nabla \cdot \mathbf { B } = \mathbf { 0 }\]

Faraday’s Law

Faraday’s law describes how a time-varying magnetic field (or flux) induces an electric field. The principle behind this phenomenon is used in many electric generators. Both macroscopic and microscopic differential equations are the same, relating electric field (E) to the time-partial derivative of magnetic field (B):

\[\nabla \times \mathbf { E } = - \frac { \partial \mathbf { B } } { \partial \mathbf { t } }\]

Ampere’s Circuital Law (with Maxwell’s correction)

Ampere’s law originally stated that magnetic field could be created by electrical current. Maxwell added a second source of magnetic fields in his correction: a changing electric field (or flux), which would induce a magnetic field even in the absence of an electrical current. He named the changing electric field “displacement current.”

Maxwell’s correction shows that self-sustaining electromagnetic waves (light) can travel through empty space even in the absence of moving charges or currents, with the electric field component and magnetic field component each continually changing and each perpetuating the other.

Electromagnetic Waves : Electric (red) and magnetic (blue) waves propagate in phase sinusoidally, and perpendicularly to one another.

The microscopic approach to the Maxwell-corrected Ampere’s law relates magnetic field (B) to current density (J, or current per unit cross sectional area) and the time-partial derivative of electric field (E):

\[\nabla \times \mathbf { B } = \mu _ { 0 } \mathbf { J } + \mu _ { 0 } \epsilon _ { 0 } \frac { \partial \mathbf { E } } { \partial t }\]

The Production of Electromagnetic Waves

Electromagnetic waves are the combination of electric and magnetic field waves produced by moving charges.

• Explain the self-perpetuating behavior of an electromagnetic wave

Electromagnetic waves

Electromagnetic radiation, is a form of energy emitted by moving charged particles. As it travels through space it behaves like a wave, and has an oscillating electric field component and an oscillating magnetic field. These waves oscillate perpendicularly to and in phase with one another.

Electromagnetic Wave : Electromagnetic waves are a self-propagating transverse wave of oscillating electric and magnetic fields. The direction of the electric field is indicated in blue, the magnetic field in red, and the wave propagates in the positive x-direction. Notice that the electric and magnetic field waves are in phase.

The creation of all electromagnetic waves begins with a charged particle. This charged particle creates an electric field (which can exert a force on other nearby charged particles). When it accelerates as part of an oscillatory motion, the charged particle creates ripples, or oscillations, in its electric field, and also produces a magnetic field (as predicted by Maxwell’s equations).

Once in motion, the electric and magnetic fields created by a charged particle are self-perpetuating—time-dependent changes in one field (electric or magnetic) produce the other. This means that an electric field that oscillates as a function of time will produce a magnetic field, and a magnetic field that changes as a function of time will produce an electric field. Both electric and magnetic fields in an electromagnetic wave will fluctuate in time, one causing the other to change.

Electromagnetic waves are ubiquitous in nature (i.e., light) and used in modern technology—AM and FM radio, cordless and cellular phones, garage door openers, wireless networks, radar, microwave ovens, etc. These and many more such devices use electromagnetic waves to transmit data and signals.

All the above sources of electromagnetic waves use the simple principle of moving charge, which can be easily modeled. Placing a coin in contact with both terminals of a 9-volt battery produces electromagnetic waves that can be detected by bringing the antenna of a radio (tuned to a static-producing station) within a few inches of the point of contact.

Energy and Momentum

Electromagnetic waves have energy and momentum that are both associated with their wavelength and frequency.

• Relate energy of an electromagnetic wave with the frequency and wavelength

Electromagnetic radiation can essentially be described as photon streams. These photons are strictly defined as massless, but have both energy and surprisingly, given their lack of mass, momentum, which can be calculated from their wave properties.

Waves were poorly understood until the 1900s, when Max Planck and Albert Einstein developed modern corrections to classical theory.

Planck theorized that “black bodies” (thermal radiators) and other forms of electromagnetic radiation existed not as spectra, but in discrete, “quantized” form. In other words, there were only certain energies an electromagnetic wave could have. In his work he developed what is now known as “Planck’s constant,” which is approximately equal to 6.626×10 -34 J·s.

The energy (E) of a photon can be related to its frequency (f) by Planck’s constant (h):

\[\mathrm { E } = \mathrm { hf } = \frac { \mathrm { hc } } { \lambda }\]

The ratio of speed of light (c) to wavelength (λ) can be substituted in place of f to give the same equation to energy in different terms. Note that energy cannot take any value: it can only exist in increments of frequency times Planck’s constant (or Planck’s constant times c divided by wavelength). Energy of a wave is therefore “quantized. ”

Wavelength : Wavelength of the sinusoidal function is represented by λ.

Momentum is classically defined as the product of mass and velocity and thus would intuitively seem irrelevant to a discussion of electromagnetic radiation, which is both massless and composed of waves.

However, Einstein proved that light can act as particles in some circumstances, and that a wave-particle duality exists. And, given that he related energy and mass (E=mc 2 ), it becomes more conceivable that a wave (which has an energy value) not only has an equation to mass but a momentum as well.

And indeed, Einstein proved that the momentum (p) of a photon is the ratio of its energy to the speed of light.

\[\mathrm { p } = \dfrac { \mathrm { E } } { \mathrm { c } } = \dfrac { \mathrm { hf } } { \mathrm { c } } = \dfrac { \mathrm { h } } { \lambda }\]

Substituting E with hc/λ cancels the c terms, making momentum also equal to the simple ratio of Planck’s constant to wavelength.

The Speed of Light

The speed of light in a vacuum is one of the most fundamental constant in physics, playing a pivotal role in modern physics.

• Relate speed of light with the index of refraction of the medium

The speed of light is generally a point of comparison to express that something is fast. shows a scale representation of the time it takes a beam of light to reach the moon from Earth. But what exactly is the speed of light?

Light Going from Earth to the Moon : A beam of light is depicted travelling between the Earth and the Moon in the time it takes a light pulse to move between them: 1.255 seconds at their mean orbital (surface-to-surface) distance. The relative sizes and separation of the Earth–Moon system are shown to scale.

It is just that: the speed of a photon or light particle. The speed of light in a vacuum (commonly written as c) is 299,792,458 meters per second. This is a universal physical constant used in many areas of physics. For example, you might be familiar with the equation:

\[\mathrm { E } = \mathrm { mc } ^ { 2 }\]

where E = Energy and m = mass. This is known as the mass-energy equivalence, and it uses the speed of light to interrelate space and time. This not only explains the energy a body of mass contains, but also explains the hindrance mass has on speed.

There are many uses for the speed of light in a vacuum, such as in special relativity, which says that c is the natural speed limit and nothing can move faster than it. However, we know from our understanding of physics (and previous atoms) that the speed at which something travels also depends on the medium through which it is traveling. The speed at which light propagates through transparent materials (air, glass, etc.,) is dependent on the refractive index of that material, n:

\[\mathrm { v } = \dfrac { \mathrm { c } } { \mathrm { n } }\]

where v = actual velocity of light moving through the medium, c = speed of light in a vacuum, and n = refractive index of medium. The refractive index of air is about 1.0003, and from this equation we can find that the speed of visible light in air is about 90 km/s slower than c.

As mentioned earlier, the speed of light (usually of light in a vacuum) is used in many areas of physics. Below is an example of an application of the constant c.

The Lorentz Factor

Fast-moving objects exhibit some properties that are counterintuitive from the perspective of classical mechanics. For example, length contracts and time dilates (runs slower) for objects in motion. The effects are typically minute, but are noticeable at sufficiently high speeds. The Lorentz factor (γ) is the factor by which length shortens and time dilates as a function of velocity (v):

\[\gamma = \left( 1 - \mathrm{ v } ^ { 2 } / \mathrm { c } ^ { 2 } \right) ^ { - 1 / 2 } \gamma = \left( 1 - \mathrm { v } ^ { 2 } / \mathrm { c } ^ { 2 } \right) ^ { - 1 / 2 } \gamma = \left( 1 - \mathrm { v } ^ { 2 } / \mathrm { c } ^ { 2 } \right) ^ { - 1 / 2 }\]

At low velocities, the quotient of v 2 /c 2 is sufficiently close to 0 such that γ is approximately 1. However, as velocity approaches c, γ increases rapidly towards infinity.

The Doppler Effect

The Doppler Effect is the change in a wave’s perceived frequency that results from the source’s motion, the observer, and the medium.

• Give examples of daily observations of the Doppler effect

The Doppler effect is a periodic event’s change in frequency for an observer in motion relative to the event’s source. Typically, this periodic event is a wave.

Most people have experienced the Doppler effect in action. Consider an emergency vehicle in motion, sounding its siren. As it approaches an observer, the pitch of the sound (its frequency) sounds higher than it actually is. When the vehicle reaches the observer, the pitch is perceived as it actually is. When the vehicle continues away from the observer, the pitch is perceived as lower than it actually is. From the perspective of an observer inside the vehicle, the pitch of the siren is constant.

The Doppler Effect and Sirens : Waves emitted by a siren in a moving vehicle

The difference in the perceived pitch depending on observer location can be explained by the fact that the siren’s position changes as it emits waves. A wave of sound is emitted by a moving vehicle every millisecond. The vehicle ‘chases’ each wave in one direction. By the time the next wave is emitted, it is closer (relative to an onlooker ahead of the vehicle) to the previous wave than the wave’s frequency would suggest. Relative to an onlooker behind the vehicle, the second wave is further from the first wave than one would expect, which suggests a lower frequency.

The Doppler effect can be caused by any kind of motion. In the example above, the siren moved relative to a stationary observer. If the observer moves relative to the stationary siren, the observer will notice the Doppler effect on the pitch of the siren. Finally, if the medium through which the waves propagate moves, the Doppler effect will be noticed even for a stationary observer. An example of this phenomenon is wind.

Quantitatively, the Doppler effect can be characterized by relating the frequency perceived (f) to the velocity of waves in the medium (c), the velocity of the receiver relative to the medium (v r ), the velocity of the source relative to the medium (v s ), and the actual emitted frequency (f 0 ):

\[\mathrm { f } = \left( \dfrac { \mathrm { c } + \mathrm { v } _ { \mathrm { r } } } { \mathrm { c } + \mathrm { v } _ { \mathrm { s } } } \right) \mathrm { f } _ { 0 }\]

The Doppler Effect : Wavelength change due to the motion of source

Momentum Transfer and Radiation Pressure Atom

Radiation pressure is the pressure exerted upon any surface exposed to electromagnetic (EM) radiation.

• Explain formation of radiation pressure

Radiation pressure is the pressure exerted upon any surface exposed to electromagnetic (EM) radiation. EM radiation (or photon, which is a quantum of light) carries momentum; this momentum is transferred to an object when the radiation is absorbed or reflected. Perhaps one of the most well know examples of the radiation pressure would be comet tails. Haley’s comet is shown in.

Halley’s Comet : As a comet approaches the inner Solar System, solar radiation causes the volatile materials within the comet to vaporize and stream out of the nucleus. The streams of dust and gas thus released form an atmosphere around the comet (called the coma), and the force exerted on the coma by the Sun’s radiation pressure and solar wind cause the formation of an enormous tail that points away from the Sun.

Although radiation pressure can be understood using classical electrodynamics, here we will examine the quantum mechanical argument. From the perspective of quantum theory, light is made of photons: particles with zero mass but which carry energy and – importantly in this argument – momentum. According to special relativity, because photons are devoid of mass, their energy (E) and momentum (p) are related by E=pc.

Now consider a beam of light perpendicularly incident on a surface, and let us assume the beam of light is totally absorbed. The momentum the photons carry is a conserved quantity (i.e., it cannot be destroyed) so it must be transferred to the surface; thus the absorption of the light beam causes the surface to gain momentum. Newton’s Second Law tells us that force equals rate of change of momentum; thus during each second, the surface experiences a force (or pressure, as pressure is force per unit area) due to the momentum the photons transfer to it.

This gives us: pressure = momentum transferred per second per unit area = energy deposited per second per unit area / c = I/c, (where I is the intensity of the beam of light).

Laser Cooling

There are many variations of laser cooling, but they all use radiation pressure to remove energy from atomic gases (and therefore cool the sample). In laser cooling (sometimes called Doppler cooling), the frequency of light is tuned slightly below an electronic transition in the atom. Because light is detuned to the “red” (i.e., at lower frequency) of the transition, the atoms will absorb more photons if they move towards the light source, due to the Doppler effect. Thus if one applies light from two opposite directions, the atoms will always scatter more photons from the laser beam pointing opposite to their direction of motion (typical setups applies three opposing pairs of laser beams as in ).

The Magneto Optical Trap : Experimental setup of Magneto Optical Trap (MOT), which uses radiation pressure to cool atomic species. Atoms are slowed down by absorbing (and emitting) photons.

In each scattering event, the atom loses a momentum equal to the momentum of the photon. If the atom (which is now in the excited state) then emits a photon spontaneously, it will be kicked by the same amount of momentum, only in a random direction. Since the initial momentum loss was opposite to the direction of motion (while the subsequent momentum gain was in a random direction), the overall result of the absorption and emission process is to reduce the speed of the atom. If the absorption and emission are repeated many times, the average speed (and therefore the kinetic energy ) of the atom will be reduced. Since the temperature of a group of atoms is a measure of the average random internal kinetic energy, this is equivalent to cooling the atoms. Simple laser cooling setups can produce a cold sample of atomic gases at around 1mK (=10 -3 K) starting from a room temperature gas.

• Maxwell’s four equations describe how electric charges and currents create electric and magnetic fields, and how they affect each other.
• Gauss’s law relates an electric field to the charge(s) that create(s) it.
• Gauss’s law for magnetism states that there are no “magnetic charges” analogous to electric charges, and that magnetic fields are instead generated by magnetic dipoles.
• Faraday’s law describes how a time-varying magnetic field (or flux ) induces an electric field. The principle behind this phenomenon is used in many electric generators.
• Ampere ‘s law originally stated that a magnetic field is created by an electrical current. Maxwell added that a changing electric flux can also generate a magnetic field.
• Electromagnetic waves consist of both electric and magnetic field waves. These waves oscillate in perpendicular planes with respect to each other, and are in phase.
• The creation of all electromagnetic waves begins with an oscillating charged particle, which creates oscillating electric and magnetic fields.
• Once in motion, the electric and magnetic fields that a charged particle creates are self-perpetuating: time-dependent changes in one field (electric or magnetic) produce the other.
• Max Planck proved that energy of a photon (a stream of which is an electromagnetic wave ) is quantized and can exist in multiples of “Planck’s constant” (denoted as h, approximately equal to 6.626×10 -34 J·s).
• \(\mathrm { E } = \mathrm { hf } = \frac { \mathrm { hc } } { \lambda } \)describes the energy (E) of a photon as a function of frequency (f), or wavelength (λ).
• \(\mathrm { p } = \frac { \mathrm { E } } { \mathrm { c } } = \frac { \mathrm { hf } } { \mathrm { c } } = \frac { \mathrm { h } } { \lambda }\) describes the momentum (p) of a photon as a function of its energy, frequency, or wavelength.
• The maximum possible value for the speed of light is that of light in a vacuum, and this speed is used for a constant in many area of physics.
• c is the symbol used to represent the speed of light in a vacuum, and its value is 299,792,458 meters per second.
• When light travels through medium, its speed is hindered by the index of refraction of that medium. Its actual speed can be found with: \(v=\frac{c}{n}\).
• The Doppler effect is very commonly observed in action.
• The Doppler effect can be observed in the apparent change in pitch of a siren on an emergency vehicle, according to a stationary observer.
• The observer will notice the Doppler effect on the pitch of the stationary siren when moving relative to its pitch, or if the medium moves when the observer is stationary.
• Photons carry momentum (p = E/c). When photons are absorbed or reflected on a surface, the surface receives momentum kicks. This momentum transfer leads to radiation pressure.
• Electromagnetic radiation applies radiation pressure equal to the Intensity (of light beam) divided by c (speed of light).
• Laser cooling uses radiation pressure to remove energy from atomic gases. The technique can produce cold samples of gases at 1mK or so.
• differential equation : An equation involving the derivatives of a function.
• flux : A quantitative description of the transfer of a given vector quantity through a surface. In this context, we refer to the electric flux and magnetic flux.
• electromagnetic wave : A wave of oscillating electric and magnetic fields.
• phase : Waves are said to be “in phase” when they begin at the same part (e.g., crest) of their respective cycles.
• photon : The quantum of light and other electromagnetic energy, regarded as a discrete particle having zero rest mass, no electric charge, and an indefinitely long lifetime.
• wavelength : The length of a single cycle of a wave, as measured by the distance between one peak or trough of a wave and the next; it is often designated in physics as λ, and corresponds to the velocity of the wave divided by its frequency.
• frequency : The quotient of the number of times n a periodic phenomenon occurs over the time t in which it occurs: f = n / t.
• special relativity : A theory that (neglecting the effects of gravity) reconciles the principle of relativity with the observation that the speed of light is constant in all frames of reference.
• refractive index : The ratio of the speed of light in air or vacuum to that in another medium.
• doppler effect : Apparent change in frequency of a wave when the observer and the source of the wave move relative to each other.
• classical electrodynamics : A branch of theoretical physics that studies consequences of the electromagnetic forces between electric charges and currents.

LICENSES AND ATTRIBUTIONS

CC LICENSED CONTENT, SHARED PREVIOUSLY

• Curation and Revision. Provided by : Boundless.com. License : CC BY-SA: Attribution-ShareAlike

CC LICENSED CONTENT, SPECIFIC ATTRIBUTION

• flux. Provided by : Wiktionary. Located at : http://en.wiktionary.org/wiki/flux . License : CC BY-SA: Attribution-ShareAlike
• differential equation. Provided by : Wiktionary. Located at : http://en.wiktionary.org/wiki/differential_equation . License : CC BY-SA: Attribution-ShareAlike
• Maxwell's equations. Provided by : Wikipedia. Located at : http://en.Wikipedia.org/wiki/Maxwell's_equations . License : CC BY-SA: Attribution-ShareAlike
• Electromagneticwave3D. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/File:Electromagneticwave3D.gif . License : CC BY-SA: Attribution-ShareAlike
• GaussLaw1. Provided by : Wikimedia. Located at : http://upload.wikimedia.org/Wikipedia/commons/5/57/GaussLaw1.svg . License : CC BY-SA: Attribution-ShareAlike
• VFPt dipole magnetic1. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/File:VFPt_dipole_magnetic1.svg . License : CC BY-SA: Attribution-ShareAlike
• Electromagnetic radiation. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Electromagnetic_radiation . License : CC BY-SA: Attribution-ShareAlike
• electromagnetic wave. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/electromagnetic%20wave . License : CC BY-SA: Attribution-ShareAlike
• phase. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/phase . License : CC BY-SA: Attribution-ShareAlike
• Onde electromagnetique. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/File:Onde_electromagnetique.svg . License : CC BY-SA: Attribution-ShareAlike
• wavelength. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/wavelength . License : CC BY-SA: Attribution-ShareAlike
• frequency. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/frequency . License : CC BY-SA: Attribution-ShareAlike
• photon. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/photon . License : CC BY-SA: Attribution-ShareAlike
• Sine wavelength. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/File:Sine_wavelength.svg . License : CC BY-SA: Attribution-ShareAlike
• refractive index. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/refractive_index . License : CC BY-SA: Attribution-ShareAlike
• Speed of light. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Speed_of_light . License : CC BY-SA: Attribution-ShareAlike
• special relativity. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/special_relativity . License : CC BY-SA: Attribution-ShareAlike
• Speed of light. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Speed_of_light . License : Public Domain: No Known Copyright
• Doppler effect. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Doppler_effect . License : CC BY-SA: Attribution-ShareAlike
• Boundless. Provided by : Boundless Learning. Located at : www.boundless.com//physics/definition/doppler-effect--2 . License : CC BY-SA: Attribution-ShareAlike
• Dopplerfrequenz. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/File:Dopplerfrequenz.gif . License : CC BY-SA: Attribution-ShareAlike
• Doppler effect diagrammatic. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/File:Doppler_effect_diagrammatic.png . License : CC BY-SA: Attribution-ShareAlike
• Radiation pressure. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Radiation_pressure . License : CC BY-SA: Attribution-ShareAlike
• classical electrodynamics. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/classical%20electrodynamics . License : CC BY-SA: Attribution-ShareAlike
• Electromagneticwave3D. Provided by : Wikipedia. Located at : http://en.Wikipedia.org/wiki/File:Electromagneticwave3D.gif . License : CC BY-SA: Attribution-ShareAlike
• VFPt dipole magnetic1. Provided by : Wikipedia. Located at : http://en.Wikipedia.org/wiki/File:VFPt_dipole_magnetic1.svg . License : CC BY-SA: Attribution-ShareAlike
• Comet. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Comet . License : CC BY: Attribution
• Magneto-optical trap. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Magneto-optical_trap . License : CC BY: Attribution

Electromagnetic spectrum

The electromagnetic spectrum is a range of wavelengths of electromagnetic radiation. From long to short wavelength, the EM spectrum includes radio waves, microwaves, infrared, visible light, ultraviolet, x-rays and gamma rays.

Energy is propagated through space in the form of electromagnetic (EM) waves, which are composed of oscillating electric and magnetic fields. EM waves do not require a substance (like air or water) to travel through, meaning that — unlike sound — they can travel through empty space. In a vacuum, all EM waves travel at the same speed: the speed of light (which is itself an EM wave). Like all waves, an EM wave is characterised by its wavelength, and the range of wavelengths we observe, from very long to very short, is what we refer to as the EM spectrum. We divide up the EM spectrum roughly according to how the waves behave when they interact with matter and each division has a name. So we have: radio waves, which have the longest wavelengths; microwaves; infrared; visible light; ultraviolet; x-rays; and finally gamma rays, which have the shortest wavelengths. Celestial objects such as stars, planets and galaxies all emit EM waves at various wavelengths and so different telescopes are designed to be sensitive to different parts of the EM spectrum. EM radiation in and around the visible part of the spectrum is often referred to broadly as ‘light’, with shorter wavelengths referred to as ‘bluer’ and longer wavelengths referred to as ‘redder’.

By combining observations at different wavelengths, we can develop a more complete picture of the structure, composition and behaviour of an object than visible wavelengths alone can show. This makes Webb especially important, alongside existing telescopes such as the NASA/ESA Hubble Space Telescope . Webb's sensitive instruments provide excellent coverage of near- and mid-infrared wavelengths, enabling high-quality research into celestial objects that emit this kind of light, and providing critical extra details about targets also being studied at longer and shorter wavelengths.

The eighteen hexagonal mirrors that together make up Webb's primary mirror are coated in a thin layer of gold. This gives the telescope a distinctive look, but more importantly it's perfect for reflecting the infrared wavelengths to which Webb's instruments are sensitive. Webb has four instruments which all work in the infrared range: MIRI , which detects mid-infrared light, and NIRSpec ,  NIRCam and NIRISS , which are all sensitive to near-infrared light.

Even before cooperating with other telescopes, MIRI and NIRCam are frequently used together to obtain a more complete picture of a target over the whole of Webb's wavelength range. This image of the Pillars of Creation shows the different details which are highlighted in the different wavelength ranges — stars, particularly newly-formed stars, show up in near-infrared, while dust is placed on display by MIRI.

• school Campus Bookshelves
• menu_book Bookshelves
• perm_media Learning Objects
• login Login
• how_to_reg Request Instructor Account
• hub Instructor Commons
• Download Page (PDF)
• Download Full Book (PDF)
• Periodic Table
• Physics Constants
• Scientific Calculator
• Reference & Cite
• Tools expand_more
• Readability

selected template will load here

This action is not available.

13.1: Electromagnetic Waves

• Last updated
• Save as PDF
• Page ID 2843

Did you ever wonder how a microwave works? It directs invisible waves of radiation toward the food placed inside of it. The radiation transfers energy to the food, causing it to get warmer. The radiation is in the form of microwaves, which are a type of electromagnetic waves.

What Are Electromagnetic Waves?

Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. Like other waves, electromagnetic waves transfer energy from one place to another. The transfer of energy by electromagnetic waves is called electromagnetic radiation . Electromagnetic waves can transfer energy through matter or across empty space.

Q: How do microwaves transfer energy inside a microwave oven?

A: They transfer energy through the air inside the oven to the food.

May the Force Be With You

A familiar example may help you understand the vibrating electric and magnetic fields that make up electromagnetic waves. Consider a bar magnet, like the one in the Figure below. The magnet exerts magnetic force over an area all around it. This area is called a magnetic field. The field lines in the diagram represent the direction and location of the magnetic force. Because of the field surrounding a magnet, it can exert force on objects without touching them. They just have to be within its magnetic field.

Q: How could you demonstrate that a magnet can exert force on objects without touching them?

A: You could put small objects containing iron, such as paper clips, near a magnet and show that they move toward the magnet.

An electric field is similar to a magnetic field. It is an area of electrical force surrounding a positively or negatively charged particle. You can see electric fields in the following Figure below. Like a magnetic field, an electric field can exert force on objects over a distance without actually touching them.

How an Electromagnetic Wave Begins

An electromagnetic wave begins when an electrically charged particle vibrates. The Figure below shows how this happens. A vibrating charged particle causes the electric field surrounding it to vibrate as well. A vibrating electric field, in turn, creates a vibrating magnetic field. The two types of vibrating fields combine to create an electromagnetic wave.

How an Electromagnetic Wave Travels

As you can see in the Figure above, the electric and magnetic fields that make up an electromagnetic wave are perpendicular (at right angles) to each other. Both fields are also perpendicular to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. However, unlike a mechanical transverse wave, which can only travel through matter, an electromagnetic transverse wave can travel through empty space. When waves travel through matter, they lose some energy to the matter as they pass through it. But when waves travel through space, no energy is lost. Therefore, electromagnetic waves don’t get weaker as they travel. However, the energy is “diluted” as it travels farther from its source because it spreads out over an ever-larger area.

Electromagnetic Wave Interactions

When electromagnetic waves strike matter, they may interact with it in the same ways that mechanical waves interact with matter. Electromagnetic waves may:

• reflect, or bounce back from a surface;
• refract, or bend when entering a new medium;
• diffract, or spread out around obstacles.

Electromagnetic waves may also be absorbed by matter and converted to other forms of energy. Microwaves are a familiar example. When microwaves strike food in a microwave oven, they are absorbed and converted to thermal energy, which heats the food.

Sources of Electromagnetic Waves

The most important source of electromagnetic waves on Earth is the sun. Electromagnetic waves travel from the sun to Earth across space and provide virtually all the energy that supports life on our planet. Many other sources of electromagnetic waves depend on technology. Radio waves, microwaves, and X rays are examples. We use these electromagnetic waves for communications, cooking, medicine, and many other purposes.

Launch the Light Wave simulation below to help you visualize light as a transverse wave moving through the electromagnetic field. Be sure to adjust the wavelength band slider to observe waves of different sizes, such as Radio Waves and X-Rays. There is also an illustration of objects of comparable sizes next to the electromagnetic spectrum to help you imagine the sizes of these invisible light waves.

Interactive Element

• Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. They transfer energy through matter or across space. The transfer of energy by electromagnetic waves is called electromagnetic radiation.
• The electric and magnetic fields of an electromagnetic wave are areas of electric or magnetic force. The fields can exert force over objects at a distance.
• An electromagnetic wave begins when an electrically charged particle vibrates. This causes a vibrating electric field, which in turn creates a vibrating magnetic field. The two vibrating fields together form an electromagnetic wave.
• An electromagnetic wave is a transverse wave that can travel across space as well as through matter. When it travels through space, it doesn’t lose energy to a medium as a mechanical wave does.
• When electromagnetic waves strike matter, they may be reflected, refracted, or diffracted. Or they may be absorbed by matter and converted to other forms of energy.
• The most important source of electromagnetic waves on Earth is the sun. Many other sources of electromagnetic waves depend on technology.
• What is an electromagnetic wave?
• Define electromagnetic radiation.
• Describe the electric and magnetic fields of an electromagnetic wave.
• How does an electromagnetic wave begin? How does it travel?
• Compare and contrast electromagnetic and mechanical transverse waves.
• List three sources of electromagnetic waves on Earth.

Explore More

Watch the electromagnetic wave animation and then answer the questions below.

• Identify the vibrating electric and magnetic fields of the wave.
• Describe the direction in which the wave is traveling.

Additional Resources

Study Guide: Wave Optics Study Guide

Real World Application: Printing with Light, The Incredible Hulk

PLIX: Play, Learn, Interact, eXplore: Energy Levels: Bohr's Atomic Model

• April 4, 2024 | Effective Anger Management: Chilling Out vs. Blowing Off Steam
• April 4, 2024 | Chilling Revelations: Ice Shells Expose Alien Ocean Temperatures
• April 3, 2024 | Could Modified RNA Be the Key to Healing Neurodegeneration Caused by Brain Disorders Like Alzheimer’s?
• April 3, 2024 | A Lunar Orbit That’s Just Right for Humanity’s First Space Station Around the Moon
• April 3, 2024 | Redefining Quantum Communication: Researchers Have Solved a Foundational Problem in Transmitting Quantum Information

Astronomy & Astrophysics 101: Electromagnetic Spectrum

By ESA/Hubble April 24, 2022

What Is the Electromagnetic Spectrum?

The electromagnetic spectrum is a range of frequencies of electromagnetic radiation. From long to short wavelength, the EM spectrum includes radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays.

Energy travels through space as electromagnetic (EM) waves, which are made up of oscillating electric and magnetic fields. EM waves do not require a material (such as air or water) to move through, hence they can, unlike sound, travel through empty space. All electromagnetic waves travel at the same speed in a vacuum: the speed of light (which is itself an EM wave).

An EM wave, like other waves, is defined by its wavelength, and the range of wavelengths we observe, from extremely long to very short, is referred to as the EM spectrum. The electromagnetic spectrum is loosely divided into divisions based on how the waves behave when they interact with matter, and each division is given a name. Radio waves have the longest wavelengths, followed by microwaves, infrared, visible light, ultraviolet, x-rays, and finally gamma rays, which have the shortest wavelengths. 

Celestial objects such as stars , planets , and galaxies all emit electromagnetic waves at various wavelengths, therefore telescopes are built to be sensitive to different sections of the electromagnetic spectrum. Shorter wavelengths are referred to as ‘bluer,’ while longer wavelengths are referred to as’redder.’ EM radiation in and near the visible region of the spectrum is generally referred to broadly as ‘light.’

We can construct a more complete image of an object’s structure, composition, and behavior by combining observations at different wavelengths than visible wavelengths alone can convey.

For more than three decades, Hubble has studied the Universe using its 2.4-meter primary mirror and its five science instruments. They observe primarily in the ultraviolet and visible parts of the spectrum, but also have some near- infrared capabilities. Hubble observes in different wavelength bands, one band at a time, each providing different information on the object under study. Each of these wavelengths is reproduced in a different color and these are combined to form a composite image that well resembles the true emission from that celestial object.

Astronomers have used this set of single-color images, shown around the edge, to construct the color picture (center) of a ring of star clusters surrounding the core of the galaxy NGC 1512. These pictures were taken by the NASA/ESA Hubble Space Telescope’s Faint Object Camera (FOC), Wide Field and Planetary Camera 2 (WFPC2), and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). Each image represents a specific color or wavelength region of the spectrum, from ultraviolet to near infrared, and shows the wide wavelength region covered by Hubble. Celestial bodies emit light at a variety of wavelengths, anywhere from gamma rays to radio waves. Astronomers chose to study NGC 1512 in these colors to emphasize important details in the ring of young star clusters surrounding the core. Credit: NASA, ESA, Dan Maoz (Tel-Aviv University, Israel, and Columbia University, USA)

By exploring the image above, you can see how astronomers have used a set of single-color images to construct the color picture of a ring of star clusters surrounding the core of the galaxy NGC 1512. Each image represents a specific color or wavelength region of the spectrum, from ultraviolet to near-infrared, and shows the wide wavelength range covered by Hubble. Astronomers chose to study NGC 1512 in these colors to emphasize important details in the ring of young star clusters surrounding the core.

Electromagnetic Spectrum. Credit: ESA/Hubble

Astronomers use multi-wavelength imagery to study details that might not otherwise be present in visible images. For example, a new multiwavelength observation of Jupiter released in 2020 by Hubble in ultraviolet/visible/near-infrared light of Jupiter gave researchers an entirely new view of the giant planet. These observations provided insights into the altitude and distribution of the planet’s haze and particles and showed Jupiter’s ever-changing cloud patterns. The planet’s aurorae are only visible in the ultraviolet; however, the structure of the red spot is well studied at visible wavelengths.

To celebrate the telescope’s 25th anniversary in 2015, Hubble unveiled two new beautiful portraits of the popular Pillars of Creation , revealing how different details can be studied in visible and near-infrared observations. While the visible light captures the multi-colored glow of gas clouds, the infrared image penetrates much of the obscuring dust and gas to uncover countless newborn stars.

We invite you to watch this Hubblecast that explores how Hubble’s observations differ across different wavelengths of the electromagnetic spectrum, and how these observations will be complemented by those of the James Webb Space Telescope .

More on SciTechDaily

Astronomy & Astrophysics 101: Infrared Astronomy

Telescopes Unite in Unprecedented Observations of Famous Black Hole Across the Entire Electromagnetic Spectrum

Unveiling a 100-year-old astrophysics mystery: where the milky way’s cosmic rays come from, by jove stunning new images show jupiter’s great red spot, superstorms, and gargantuan cyclones.

Self-Destruction of Dark Matter May Contribute to Cosmic Gamma-Ray Glow

Powerful Pulsating Gamma Rays Emitted From Neutron Star Rotating an Incredible 707 Times a Second

Best view yet of exceptional cosmic explosion – challenges established theory of gamma-ray bursts in the universe.

The Hunt for the Gravitational Wave Background: NASA’s FERMI Searches for Ripples in Spacetime

1 comment on "astronomy & astrophysics 101: electromagnetic spectrum".

“Astronomers have used this set of single-color images, shown around the edge, to construct the color picture (center) of a ring of star clusters surrounding the core of the galaxy NGC 1512.”

Because a computer display device works with just three primary colors (RGB), I would be interested in knowing just how they compressed 7 different images into three colors. Did they use band ratios or weighted averages, or some other technique?

Leave a comment Cancel reply

Email address is optional. If provided, your email will not be published or shared.

Save my name, email, and website in this browser for the next time I comment.

FREE K-12 standards-aligned STEM

curriculum for educators everywhere!

Find more at TeachEngineering.org .

• TeachEngineering
• Visible Light and the Electromagnetic Spectrum

Lesson Visible Light and the Electromagnetic Spectrum

Grade Level: 4 (3-5)

Time Required: 15 minutes

Lesson Dependency: None

Subject Areas: Physical Science

NGSS Performance Expectations:

• Print lesson and its associated curriculum

Curriculum in this Unit Units serve as guides to a particular content or subject area. Nested under units are lessons (in purple) and hands-on activities (in blue). Note that not all lessons and activities will exist under a unit, and instead may exist as "standalone" curriculum.

• Make Some Waves
• Simon Says Big Amplitude, Small Wavelength!
• Simple Instruments
• Echolocation in Action!
• Controlling Sound
• Light Scavengers
• Building a Fancy Spectrograph
• The Visual Spectrum
• Create a Pinhole Camera

TE Newsletter

Engineering connection, learning objectives, worksheets and attachments, more curriculum like this, pre-req knowledge, introduction/motivation, associated activities, lesson closure, vocabulary/definitions, user comments & tips.

Engineers use many types of electromagnetic waves. Gamma radiation is emitted by fuel rods in nuclear power plants, x-rays are used to see inside our bodies, ultraviolet light can be used to sanitize things, microwaves are used to cook, and radio waves allow us to communicate over large distances.

After this lesson, students should be able to:

• Explain that light can be considered an electromagnetic wave.
• Give two examples of how engineers use electromagnetic waves.
• Explain that we can only see a small portion of all electromagnetic waves.

Educational Standards Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards. All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN) , a project of D2L (www.achievementstandards.org). In the ASN, standards are hierarchically structured: first by source; e.g. , by state; within source by type; e.g. , science or mathematics; within type by subtype, then by grade, etc .

Ngss: next generation science standards - science, international technology and engineering educators association - technology.

View aligned curriculum

Do you agree with this alignment? Thanks for your feedback!

State Standards

Colorado - science.

This lesson follows Lessons 1-6 of the Sound and Light Unit.

*Note: These concepts might be very difficult to visualize; if possible, create transparencies of the lesson figures for students to look at during class discussions.

Let's think about our brave adventurers for a minute – who remembers what Angie and Harmon need to do next to find the treasure? That's right – they want to use lights underwater to find the sunken treasure ship. But first, they need to learn something about light waves so that they can choose the right kind of lights to use in their exploration.

When we learned about sound, we discovered that sound travels in waves. Light can also be thought of as a wave – light is a form of an electromagnetic wave . That's a big word, so let's write it on the board.

An electromagnetic wave is a type of wave that can travel through empty space... Yes, you heard correctly, empty space. Unlike sound waves, which need "something" to travel through (for example, water or air), electromagnetic waves are able to travel through "emptiness" or a vacuum.

This picture (show Electromagnetic Transparency #1– in the Attachments section) shows different kinds of electromagnetic waves. Engineers use electromagnetic waves for many different purposes. Gamma rays (nuclear power plant radiation), x-rays, light, microwaves, and radio waves (including cell phone waves) are all electromagnetic waves. What makes all these waves different from each other are their wavelengths and frequencies.

Who would like to remind the class what frequency is? That's right! The frequency of a wave is the number of times a crest occurs each second. Some waves have really big — or even really small — frequencies. If a wave has a higher frequency (many waves in a certain amount of time), it has more energy. And, if a wave has a smaller frequency (fewer waves in a certain amount of time), it has less energy.

Let's look at another picture (show Electromagnetic Transparency #2) to see if we can figure out which waves have the most energy. Which waves do you think are the most powerful? That's right! gamma waves have very high frequencies and, consequently, have a lot of energy. This extreme amount of energy is one reason why gamma waves are very dangerous if improperly used.

Have any of you ever had an x-ray? X-rays are not as strong as gamma rays, but they are still very powerful. A sunburn? Have any of you ever burned your skin when out in the hot sun (or overcast as well) too long? Sunburns come from ultraviolet light, which we cannot see, but can still burn our skin. Radio waves and microwaves have a smaller frequency, so they are much less powerful than x-rays or ultraviolet light. Waves are fascinating, that's for sure!

We know that waves with high frequencies have a lot of energy. And, the waves that have smaller frequencies have less energy — think of these wave types as energetic waves that move very fast and lazy waves that move slow. Did you know that we cannot see most electromagnetic waves? The small section of the spectrum with the waves that we can see is called the visible spectrum , and the wavelengths that we can see allow us to see the colors of red, orange, yellow, green, blue, indigo, violet — the colors of the rainbow! We do not usually think of visible light (the visible spectrum) as being an electromagnetic wave, but it is. Figure 2 shows where visible light falls on the electromagnetic spectrum.

Engineers use electromagnetic waves in all sorts of different inventions. We cannot see most electromagnetic waves, but you do observe these waves every day when you see visible light. Today we are going to build a fascinating invention so that we can see the different colors that are a part of visible light. Following the lesson, students can use the associated activity Building a Fancy Spectrograph to build their own device from simple materials to observe the spectra of different light sources! Then students can follow-up with the associated activity The Visual Spectrum to compare their findings between different light sources. Let's get started!

Lesson Background and Concepts for Teachers

A wave is a change (a variation) that travels through a substance (or medium). You can often see the change, such as the increased height of a traveling ocean, but what is important to understand is that the medium itself does not travel with the wave.

Ripples in a pond are good examples of waves. If no wind, a pond is smooth until a rock is thrown in and disturbs the water. Then ripples, "disturbances" in the pond, travel to the edges. The medium in this case is the water, through which the ripples travel. The water is not actually moving, but the waves (ripples) are.

Waves move in two ways: longitudinally and transversely . Transverse waves oscillate (move back and forth) in a direction perpendicular to their motion. Our pond ripples, for instance, oscillate up and down but move horizontally towards the edge of the pond. Because the ripples oscillate perpendicular to their horizontal motion towards the edge, they can be classified as transverse waves.

An electromagnetic wave is a transverse wave that can travel through empty space or a vacuum. Literally, electromagnetic waves are able to travel through "emptiness," unlike sound waves, which need "something" to travel through (for example, water or air). Electromagnetic waves have two parts to them: electric and magnetic. Both of these parts are considered transverse waves.

Waves with high frequencies have a lot of energy, and, waves with smaller frequencies have less energy. Most electromagnetic waves are not visible. However, a small section of the spectrum includes waves that we can see — it is called the visible spectrum (see Figure 3). These visible wavelengths allow us to see the colors of the rainbow: red, orange, yellow, green, blue, indigo and violet. We do not usually think of visible light (the visible spectrum) as being an electromagnetic wave, but it is.

The electromagnetic spectrum can be considered from another perspective — in nanometers — specifically from 400 nm to 700 nm. Each color in this visual range has a different wavelength. Red has the longest wavelength (700 nm) and violet has the shortest wavelength (400 nm). Green occurs near the middle at about 550 nm. A prism divides light into the wavelengths that make it up. Seen together, color waves make white light. White light is especially dramatic because many different colors of the visual spectrum can combine to make white light. Two "white" light sources can have very different spectral compositions. When white light shines on a prism, the colors in white light separate from each other because they refract at different angles depending on their wavelength (see Figure 4). Water droplets in the air refract sunlight to create rainbows.

Light can be absorbed, reflected (or diffused) and refracted. Some materials can affect how light bends in more than one way, refracting and reflecting at the same time. Objects made of more than one substance usually have different reflective, refractive and absorptive properties.

Light reflects at a predictable angle: the angle of the light that strikes a surface equals the angle of the light that bounces off the surface. Rough surfaces scatter — or diffuse — light, which can cause glare, blur an image or prevent us from seeing an image.

Light changes speed and direction — refracts — when it moves from one transparent medium to another. The refractive property of transparent materials can be used to make lenses that focus light (for example, cameras, eyeglasses, telescopes).

Since visible light is the part of the electromagnetic spectrum that our eyes can see (remember, we cannot see most electromagnetic waves), our whole world is oriented around it and the colors that are produced through this visible spectrum. Understanding these visible electromagnetic waves has enabled engineers to develop many instruments that can see farther and more clearly than our eyes. That is why we use satellites to look at the Earth, and telescopes to look at the Sky!

• Building a Fancy Spectrograph - Students create and decorate their own spectrographs using simple materials and holographic diffraction gratings. A holographic diffraction grating acts like a prism, showing the visual components of light. After building the spectrographs, students observe the spectra of different light sources as homework.
• The Visual Spectrum - Students make simple spectroscopes (prisms) to look at different light sources. Using the spectroscopes, students see differing spectral distributions of different light sources

You all did a great job today of being good listeners and thinking hard about light! We learned that light can be thought of as a wave, just as sound is a wave. We also learned that our eyes can only see some wavelengths of electromagnetic radiation. What do we call the set of wavelengths that our eyes can see ? That's right---the visible spectrum. We also discovered that engineers use many different electromagnetic waves for many different applications. In our next lesson, we are going to learn about rainbows, and continue to follow the adventures of Angie and Harmon. What do you think will happen to them next?

electromagnetic wave: A transverse wave with electric and magnetic parts that travels at 300,000 km/sec. Examples are gamma waves, x-rays, light waves, microwaves, and radio waves.

visual spectrum: The range of the electromagnetic spectrum — between 400 nm and 700 nm — that our eyes can see.

Pre-Lesson Assessment

Discussion Question : Turn on a radio, and tune it to a station. Next turn on a lamp. Ask the students what the two devices (radio and lamp) have in common. (Answer: They both use electromagnetic waves.) Tell students that today we are going to learn about a few different types of electromagnetic waves.

Post-Introduction Assessment

Fill in the Table : On the left side of the classroom board, list the types of electromagnetic waves. Then work with the students to fill in the right side with ways that engineers use each type of wave. Examples of waves and their uses are:

• Gamma waves – emitted by nuclear power plants
• X-rays – used for healthcare
• Light waves – for seeing visible light
• Microwaves – for cooking
• Radio waves – for communication

Lesson Summary Assessment

What I Learned Today : At lesson end, give students time to think about what they learned. Invite a few students to volunteer something new that they learned through the lesson. (If students do not mention it, remind them that they learned that visible light is an electromagnetic wave and the only electromagnetic wave we can see; also it is only a small portion of the overall spectrum of electromagnetic waves.)

Lesson Extension Activities

Bring in small prisms for students to experiment with and explore how they break light into different wavelengths/colors.

Have students create an electromagnetic wave journal of different electromagnetic waves they experience throughout the week (for example, microwaving food, seeing a rainbow, listening to the radio, etc.).

Invite an engineer to visit the class and talk about how s/he uses electromagnetic waves in his/her research or work.

Students learn the basics of the electromagnetic spectrum and how various types of electromagnetic waves are related in terms of wavelength and energy. In addition, they are introduced to the various types of waves that make up the electromagnetic spectrum including, radio waves, ultraviolet waves, ...

Students are introduced to the correct technical vocabulary for lighting, which is different than layperson's terms. They learn about lamp (light bulb) technology and how to identify the various types of lighting in their spaces. They are also introduced to lighting controls as a means for saving en...

Students learn about the science and math that explain light behavior, which engineers have exploited to create sunglasses. They examine tinted and polarized lenses, learn about light polarization, transmission, reflection, intensity, attenuation, and how different mediums reduce the intensities of ...

Filtering is the process of removing or separating the unwanted part of a mixture. In signal processing, filtering is specifically used to remove or extract part of a signal, and this can be accomplished using an analog circuit or a digital device (such as a computer). In this lesson, students learn...

Dunbar, Brian. National Aeronautics and Space Administration, Langley Research Center, Multimedia, April 13, 2007. Accessed June 1, 2007. http://www.nasa.gov/centers/langley/images/content/114284main_EM_Spectrum500.jpg

Ferebee, Michelle T. National Aeronautics and Space Administration, Atmospheric Sciences Data Center, April 10, 2006. Accessed April 17, 2012. http://science-edu.larc.nasa.gov/EDDOCS/images/Erb/wavelength_figure.jpg

Sample, Sharon. National Aeronautics and Space Administration, Science@NASA, Science Fun, November 22, 2004. Accessed June 7, 2007. http://science.hq.nasa.gov/kids/imagers/ems/waves3.html

Contributors

Supporting program, acknowledgements.

The contents of these digital library curricula were developed by the Integrated Teaching and Learning Program under National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government. 

Last modified: July 3, 2019

Advertisement

Can humans hear in space?

• Share Content on Facebook
• Share Content on LinkedIn
• Share Content on Flipboard
• Share Content on Reddit
• Share Content via Email

The Medium of Space

Before we begin to talk about space , we should probably define it. For the purposes of this discussion, we'll consider space to be the region of the universe outside of the Earth's atmosphere.

You've probably heard that space is a vacuum . A true vacuum refers to the complete absence of matter. But how can space be a vacuum? Space contains stars , planets, asteroids , moons and comets , just to name a few cosmic bodies. Isn't that a lot of matter? How can space contain all these massive bodies and still be a vacuum?

It's because space is big. Between these large objects are millions of miles of emptiness. This empty space -- sometimes called interstellar space -- is practically devoid of all matter, so it's effectively a vacuum.

Sound waves can travel only through matter. Since there's almost no matter in interstellar space, sound can't travel through it. The distance between particles is so great that they would never collide with each other. Even if you could get a front seat for the explosion of the Death Star , you wouldn't hear anything at all.

Technically, you could argue that there are ways a human could hear in space. Let's address a few scenarios:

• Radio waves can travel through space. So, if you're wearing a space suit that contains a radio unit and one of your buddies sends you a radio message that there's pizza in the space station , you'd be able to hear it. That's because radio waves aren't mechanical -- they're electromagnetic . Electromagnetic waves can transmit energy through a vacuum. Once your radio receives the signal, it can convert the signal into sound, which will travel through the air in your space suit without a problem.
• Let's say that you're drifting through space while wearing a space suit and you accidentally bump your helmet into the Hubble Space Telescope . The collision would make a sound that you could hear, even though you're in space. That's because the sound waves would have a physical medium to move through: Your helmet and the air inside your space suit. You'd still be surrounded by a vacuum, so an independent observer wouldn't be able to hear anything, no matter how many times you rammed your head against a satellite .
• Imagine that you're an astronaut on a space shuttle mission. You've decided to step out into space but forgot to put on your space suit. You press your face against the space shuttle. You wouldn't have any air in your ears, so you couldn't hear in the traditional sense. However, you might be able to make out a few sounds through bone conduction before the perils of space caused you to expire. In bone conduction, sound waves travel through the bones of the jaw and skull to the inner ear, bypassing the eardrum. There's no need for air, so you could hear your fellow astronauts partying inside the shuttle for about 15 seconds. After that, you'd likely be unconscious and well on your way to asphyxiation.

So despite the wisdom of Hollywood filmmakers, it's impossible to hear noises in space. We suggest the next time you watch a science fiction film, you plug up your ears whenever anything happens within the vacuum of space. It'll make the film seem more realistic and probably work as a great conversational topic with your friends once the movie's over.

To learn more about space, sound and other topics, tune in to the links below.

Related HowStuffWorks Articles

• How does going to the bathroom in space work?
• How Hearing Works
• How long can a human survive in outer space?
• How NASA Works
• How Satellites Work
• How Space Suits Work
• How Space Stations Work
• How Space Tourism Works

More Great Links

• Mad Sci Network
• The Physics Classroom Tutorial
• Bone conduction. Encyclopedia Britannica. Retrieved February 26, 2008, from Encyclopedia Britannica Online. http://www.britannica.com/eb/article-9080583
• Mad Sci Network. http://www.madsci.org/
• spaceflight. Encyclopedia Britannica. Retrieved February 26, 2008, from Encyclopedia Britannica Online. http://www.britannica.com/eb/article-9384200
• Sound. Encyclopedia Britannica. Retrieved February 25, 2008, from Encyclopedia Britannica Online. http://www.britannica.com/eb/article-9109557
• The Physics Classroom Tutorial. Glenbrook South Physics. http://www.glenbrook.k12.il.us/gbssci/phys/Class/BBoard.html
• Weir, Laila. "High-Tech Hearing Bypasses Ears." Wired. September 16, 2004. http://www.wired.com/science/discoveries/news/2004/09/64963

Please copy/paste the following text to properly cite this HowStuffWorks.com article:

Ask an Explainer

How does sound travel through space.

Sound can't be carried in the empty vacuum of space because sound waves need a medium to vibrate through such as air or water. Until recently, we thought that since there is no air in space, that no sound could travel and that is still true but only up to a point. Space isn’t actually completely empty, there are large areas of gas and dust that do have the potential to carry sound waves . However, because the particles are so spread out, the sounds waves they produce are at such a low frequency, humans are incapable of hearing them. 

13.1 Types of Waves

Section learning objectives.

By the end of this section, you will be able to do the following:

• Define mechanical waves and medium, and relate the two
• Distinguish a pulse wave from a periodic wave
• Distinguish a longitudinal wave from a transverse wave and give examples of such waves

Teacher Support

The learning objectives in this section will help your students master the following standards:

• (A) examine and describe oscillatory motion and wave propagation in various types of media.

Section Key Terms

Mechanical waves.

What do we mean when we say something is a wave? A wave is a disturbance that travels or propagates from the place where it was created. Waves transfer energy from one place to another, but they do not necessarily transfer any mass. Light, sound, and waves in the ocean are common examples of waves. Sound and water waves are mechanical waves ; meaning, they require a medium to travel through. The medium may be a solid, a liquid, or a gas, and the speed of the wave depends on the material properties of the medium through which it is traveling. However, light is not a mechanical wave; it can travel through a vacuum such as the empty parts of outer space.

A familiar wave that you can easily imagine is the water wave. For water waves, the disturbance is in the surface of the water, an example of which is the disturbance created by a rock thrown into a pond or by a swimmer splashing the water surface repeatedly. For sound waves, the disturbance is caused by a change in air pressure, an example of which is when the oscillating cone inside a speaker creates a disturbance. For earthquakes, there are several types of disturbances, which include the disturbance of Earth’s surface itself and the pressure disturbances under the surface. Even radio waves are most easily understood using an analogy with water waves. Because water waves are common and visible, visualizing water waves may help you in studying other types of waves, especially those that are not visible.

Water waves have characteristics common to all waves, such as amplitude , period , frequency , and energy , which we will discuss in the next section.

Misconception Alert

Many people think that water waves push water from one direction to another. In reality, however, the particles of water tend to stay in one location only, except for moving up and down due to the energy in the wave. The energy moves forward through the water, but the water particles stay in one place. If you feel yourself being pushed in an ocean, what you feel is the energy of the wave, not the rush of water. If you put a cork in water that has waves, you will see that the water mostly moves it up and down.

[BL] [OL] [AL] Ask students to give examples of mechanical and nonmechanical waves.

Pulse Waves and Periodic Waves

If you drop a pebble into the water, only a few waves may be generated before the disturbance dies down, whereas in a wave pool, the waves are continuous. A pulse wave is a sudden disturbance in which only one wave or a few waves are generated, such as in the example of the pebble. Thunder and explosions also create pulse waves. A periodic wave repeats the same oscillation for several cycles, such as in the case of the wave pool, and is associated with simple harmonic motion. Each particle in the medium experiences simple harmonic motion in periodic waves by moving back and forth periodically through the same positions.

[BL] Any kind of wave, whether mechanical or nonmechanical, or transverse or longitudinal, can be in the form of a pulse wave or a periodic wave.

Consider the simplified water wave in Figure 13.2 . This wave is an up-and-down disturbance of the water surface, characterized by a sine wave pattern. The uppermost position is called the crest and the lowest is the trough . It causes a seagull to move up and down in simple harmonic motion as the wave crests and troughs pass under the bird.

Longitudinal Waves and Transverse Waves

Mechanical waves are categorized by their type of motion and fall into any of two categories: transverse or longitudinal. Note that both transverse and longitudinal waves can be periodic. A transverse wave propagates so that the disturbance is perpendicular to the direction of propagation. An example of a transverse wave is shown in Figure 13.3 , where a woman moves a toy spring up and down, generating waves that propagate away from herself in the horizontal direction while disturbing the toy spring in the vertical direction.

In contrast, in a longitudinal wave , the disturbance is parallel to the direction of propagation. Figure 13.4 shows an example of a longitudinal wave, where the woman now creates a disturbance in the horizontal direction—which is the same direction as the wave propagation—by stretching and then compressing the toy spring.

Tips For Success

Longitudinal waves are sometimes called compression waves or compressional waves , and transverse waves are sometimes called shear waves .

Teacher Demonstration

Transverse and longitudinal waves may be demonstrated in the class using a spring or a toy spring, as shown in the figures.

Waves may be transverse, longitudinal, or a combination of the two . The waves on the strings of musical instruments are transverse (as shown in Figure 13.5 ), and so are electromagnetic waves, such as visible light. Sound waves in air and water are longitudinal. Their disturbances are periodic variations in pressure that are transmitted in fluids.

Sound in solids can be both longitudinal and transverse. Essentially, water waves are also a combination of transverse and longitudinal components, although the simplified water wave illustrated in Figure 13.2 does not show the longitudinal motion of the bird.

Earthquake waves under Earth’s surface have both longitudinal and transverse components as well. The longitudinal waves in an earthquake are called pressure or P-waves, and the transverse waves are called shear or S-waves. These components have important individual characteristics; for example, they propagate at different speeds. Earthquakes also have surface waves that are similar to surface waves on water.

Energy propagates differently in transverse and longitudinal waves. It is important to know the type of the wave in which energy is propagating to understand how it may affect the materials around it.

Watch Physics

Introduction to waves.

This video explains wave propagation in terms of momentum using an example of a wave moving along a rope. It also covers the differences between transverse and longitudinal waves, and between pulse and periodic waves.

• After a compression wave, some molecules move forward temporarily.
• After a compression wave, some molecules move backward temporarily.
• After a compression wave, some molecules move upward temporarily.
• After a compression wave, some molecules move downward temporarily.

Fun In Physics

The physics of surfing.

Many people enjoy surfing in the ocean. For some surfers, the bigger the wave, the better. In one area off the coast of central California, waves can reach heights of up to 50 feet in certain times of the year ( Figure 13.6 ).

How do waves reach such extreme heights? Other than unusual causes, such as when earthquakes produce tsunami waves, most huge waves are caused simply by interactions between the wind and the surface of the water. The wind pushes up against the surface of the water and transfers energy to the water in the process. The stronger the wind, the more energy transferred. As waves start to form, a larger surface area becomes in contact with the wind, and even more energy is transferred from the wind to the water, thus creating higher waves. Intense storms create the fastest winds, kicking up massive waves that travel out from the origin of the storm. Longer-lasting storms and those storms that affect a larger area of the ocean create the biggest waves since they transfer more energy. The cycle of the tides from the Moon’s gravitational pull also plays a small role in creating waves.

Actual ocean waves are more complicated than the idealized model of the simple transverse wave with a perfect sinusoidal shape. Ocean waves are examples of orbital progressive waves , where water particles at the surface follow a circular path from the crest to the trough of the passing wave, then cycle back again to their original position. This cycle repeats with each passing wave.

As waves reach shore, the water depth decreases and the energy of the wave is compressed into a smaller volume. This creates higher waves—an effect known as shoaling .

Since the water particles along the surface move from the crest to the trough, surfers hitch a ride on the cascading water, gliding along the surface. If ocean waves work exactly like the idealized transverse waves, surfing would be much less exciting as it would simply involve standing on a board that bobs up and down in place, just like the seagull in the previous figure.

Additional information and illustrations about the scientific principles behind surfing can be found in the “Using Science to Surf Better!” video.

• The surfer would move side-to-side/back-and-forth vertically with no horizontal motion.
• The surfer would forward and backward horizontally with no vertical motion.

Check Your Understanding

Use these questions to assess students’ achievement of the section’s Learning Objectives. If students are struggling with a specific objective, these questions will help identify such objective and direct them to the relevant content.

• A wave is a force that propagates from the place where it was created.
• A wave is a disturbance that propagates from the place where it was created.
• A wave is matter that provides volume to an object.
• A wave is matter that provides mass to an object.
• No, electromagnetic waves do not require any medium to propagate.
• No, mechanical waves do not require any medium to propagate.
• Yes, both mechanical and electromagnetic waves require a medium to propagate.
• Yes, all transverse waves require a medium to travel.
• A pulse wave is a sudden disturbance with only one wave generated.
• A pulse wave is a sudden disturbance with only one or a few waves generated.
• A pulse wave is a gradual disturbance with only one or a few waves generated.
• A pulse wave is a gradual disturbance with only one wave generated.

What are the categories of mechanical waves based on the type of motion?

• Both transverse and longitudinal waves
• Only longitudinal waves
• Only transverse waves
• Only surface waves

In which direction do the particles of the medium oscillate in a transverse wave?

• Perpendicular to the direction of propagation of the transverse wave
• Parallel to the direction of propagation of the transverse wave

As an Amazon Associate we earn from qualifying purchases.

This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute Texas Education Agency (TEA). The original material is available at: https://www.texasgateway.org/book/tea-physics . Changes were made to the original material, including updates to art, structure, and other content updates.

Access for free at https://openstax.org/books/physics/pages/1-introduction

• Authors: Paul Peter Urone, Roger Hinrichs
• Publisher/website: OpenStax
• Book title: Physics
• Publication date: Mar 26, 2020
• Location: Houston, Texas
• Book URL: https://openstax.org/books/physics/pages/1-introduction
• Section URL: https://openstax.org/books/physics/pages/13-1-types-of-waves

© Jan 19, 2024 Texas Education Agency (TEA). The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.

• Planet Earth
• Strange News

How Fast Do Radio Waves Travel Through Space

Table of Contents:

Map reveals how long it takes radio waves to travel through space . Called Lightyear.fm, the project (pictured) was created by New York-based computer designers Brian Moore and Chris Baker with Mike Lacher and Mikhail Chernov.

Using 110 years of Billboard chart data, designers have created a stunning and mesmerising website that reveals how long it would take popular tracks to travel through the universe. Called Lightyear. fm, it is based on the premise that the radio waves travel at the speed of light, so if you were one light year away from Earth you’d only just be hearing songs released a year ago. The planets in our solar system are mere light-minutes from Earth – meaning many would be receiving broadcasts made this year from the likes of Taylor Swift and The Weeknd – but as Lightyear. fm journeys beyond our system and into the depths of the Milky Way classic tunes echo around. Click Play on the module below to take the musical tour through the Milky Way. It works best on the Chrome browser Lightyear. fm (above) is based on the premise that the radio waves travel at the speed of light, so if you were one light year away from Earth you’d only just be hearing songs released a year ago. The project -inspired by the opending credits of the 1997 film Contact -was created by New York-based computer designers Brian Moore and Chris Baker with Mike Lacher and Russia-based Mikhail ChernovThe project  – inspired by the opening credits of the 1997 film Contact – was created by New York-based computer designers Brian Moore and Chris Baker with Mike Lacher and Russia-based Mikhail Chernov.

Video advice: How Radio Waves Could Help Clear the Way to Space

There is an invisible shell of radiation surrounding our planet that can wipe out satellites and could endanger future explorers. One possible solution to this problem? Good, old-fashioned radio waves.

Electromagnetic waves chapter 12 Flashcards

study test Learn with flashcards, games, and more — for free.

• Terms in this set (42)
• Electromagnetic Waves
• Chapter 5 (Heat)
• Science vocabulary
• Science: Ch. 12
• Electromagnetic Radiation Ch.
• Chapter 12 Electromagnetic Waves
• The nation’s sick Economy chapter 14
• American History Chapter 13 Vocabulary

Upgrade to remove adsOnly RUB 2,325/yearSTUDYFlashcardsLearnWriteSpellTestPLAYMatchGravitystudy testTerms in this set (42)What are electromagnetic wavesmade by vibrating electric charges and can travel through space where matter is not present Electromagnetic waves are produced when an electric charge that moves back and forthWhat are electromagnetic wavesAn electromagnetic wave is a transverse wave. Properties of Electromagnetic WavesAll objects emit electromagnetic wavesWave frequency increases as the temperature of the material increasesradiant energyThe energy carried by an electromagnetic wave is called radiant energy. wave of speedAll electromagnetic waves travel at 300,000 km/s in the vacuum of space. (“Speed of light. “)wave of speedNothing travels faster than the speed of light. Wavelength and FrequencyThe wavelength of an electromagnetic wave is the distance from one crest to another. Waves and ParticlesThe difference between a wave and a particle might seem obvious a wave is a disturbance that carries energy, and a particle is a piece of matter.

How long would it take a radio wave to travel?

The distances to be traveled are so great that even light or radio waves take a while getting there. It takes around eight minutes for radio waves to travel from the Earth to the Sun, and four years to get from here to the nearest star.

Radio waves possess the longest wavelengths within the EM spectrum, based on NASA, varying from about . 04 inches (1 millimeter) to greater than 62 miles (100 kilometers). They likewise have the cheapest frequencies, from about 3,000 cycles per second, or 3 kilohertz, as much as about 300 billion hertz, or 300 gigahertz.

How long would it take a radio wave to travel? How far does a radio wave travel in one year? How many seconds would it take a radio wave to travel from the planet Mars to Earth when they are the closest? How fast do radio signals travel through space? How fast does red light travel in a vacuum? Do radio waves travel forever? How far does radio travel? What are the 7 minutes of terror? Do radio signals travel forever? Does redlight travel faster? How long does it take for a radio wave to travel? How long does it take for a radio wave to reach Mars? How are radio waves picked up in space? What is the speed of a radio signal?

Question: How Fast Do Radio Waves Travel Through Space

Light waves, radio waves and all of the other electromagnetic waves travel at the speed of light—about 300,000,000 meters per second!. Can radio waves travel through empty space? Electromagnetic waves.

Although the sciences generally classify EM waves into seven fundamental types, each one is manifestations of the identical phenomenon. Radio Waves: Instant Communication. Microwaves: Data as well as heat. Infrared Waves: Invisible Heat. Visible Light Sun rays. Ultraviolet Waves: Energetic Light. X-sun rays: Penetrating Radiation. Gamma Sun rays: Nuclear Energy.

Video advice: How do Radios Work?

Patreon: patreon.com/ConcerningReality

Can radio waves travel through empty space? How far do radio waves travel in 1 second? How long does it take a radio wave to travel one light year? How long does it take radio waves to reach Mars? Are radio waves faster than sound waves? What radio waves travel the farthest? How far can radio waves transmit? How fast do radio waves travel to the moon? HOW FAR CAN signals travel in space? How do radio waves propagate through space? Do all waves travel at the same speed? How long does it take a radio signal to reach Pluto? How long would it take to get to Pluto at the speed of light? How long is the communication delay between Earth and Mars? Do all radio waves travel at the speed of light? Are radio waves faster than the speed of light? Do microwaves travel at the speed of light? Can humans pick up radio signals? What are microwave frequencies? What are the 7 types of waves? Can a radio wave travel through the earth? Do radio waves ever stop?

Device Makes Radio Waves Travel Faster Than Light

(/caption) A scientist has created a gadget that can make radio waves travel faster than light. Einstein predicted that particles and information can’t travel faster than the speed of light, but phenomena like radio waves are a different story, said John Singleton, who works at the Los Alamos National Laboratory. The polarization synchrotron combines the … Continue reading “Device Makes Radio Waves Travel Faster Than Light”

One possible use for quicker than light radio waves — that are packed right into a very effective wave how big a pencil point — may be the development of a brand new generation of mobile phones that communicate straight to satellites, instead of transmitting through relay towers because they now do.

A scientist has created a gadget that can make radio waves travel faster than light. Einstein predicted that particles and information can’t travel faster than the speed of light, but phenomena like radio waves are a different story, said John Singleton, who works at the Los Alamos National Laboratory. The polarization synchrotron combines the waves with a rapidly spinning magnetic field, and the result could explain why pulsars — which are super-dense spinning stars that are a subclass of neutron stars — emit such powerful signals, a phenomenon that has baffled many scientists.

How Do Radio Waves Travel From One Radio to Another?

Please explain how this occurs.

You will find naturally sourced radio waves within nature, but we are able to create artificial radio waves having a transmitter, just like an AM or Radio or perhaps an RFID readers. The transmitter emits waves in a particular frequency, for example 13. 56 MHz. An antenna is needed to get the signal. Since all waves inside the spectrum are striking the antenna, the antenna must be tuned for this particular frequency. When the antenna continues to be tuned, the waves reaching the antenna may then be converted into information.

06. Radio Versus Sound Waves

Radio waves are produced by moving charged particles. An example of this is an electric current in a wire. This can be demonstrated with a wire, a 6-volt battery and a small radio. Turn the radio on AM so that static can be heard, attach one end of the wire to the battery. Touch the other end of the wire to the other battery terminal and have students record their observations. (When the other end of the wire is touched to the other battery terminal, you will hear the radio waves, which reach the radio get turned into sound waves, which your ears can hear.)

Draw an image from the last experiment. Inside your drawing include both people, their ears, their walkie-talkies, and also the balloon. Show the pathways from the seem waves one color as well as radio stations waves utilizing a different color. Out of your drawing, explain the reason why you first heard this balloon mechanism pop around the walkie-talkie.

• Grade Level:
• Curriculum Standards:
• Students will:
• Internet Sites:
• Procedures:
• Evaluation:

Radio waves are produced by moving charged particles. An example of this is an electric current in a wire. This can be demonstrated with a wire, a 6-volt battery and a small radio. Turn the radio on AM so that static can be heard, attach one end of the wire to the battery. Touch the other end of the wire to the other battery terminal and have students record their observations. (When the other end of the wire is touched to the other battery terminal, you will hear the radio waves, which reach the radio get turned into sound waves, which your ears can hear. ) Sound waves travel through a medium. If there is no medium then there will be no sound. Show the included video of a bell in a vacuum. When all air is removed there is no medium for the sound waves to travel through so no sound is heard.

Video advice: GCSE Physics – Radio Waves #65

In this video we cover:

Can radio waves travel through empty space?

Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space . ... This proved that radio waves were a form of light!

How long does it take for a radio wave to travel one light year?

Called Lightyear.fm, it is based on the premise that the radio waves travel at the speed of light, so if you were one light year away from Earth you'd only just be hearing songs released a year ago....

How far do radio waves travel in 1 second?

the distance a radio wave travels in a vacuum, in one second, is 299,792,458 meters (983,571,056 ft) , which is the wavelength of a 1 hertz radio signal.

How fast do communication signals travel in space?

Communications don't occur instantaneously. They're bound by a universal speed limit: the speed of light, about 186,000 miles per second . For spacecraft close to Earth, this time delay — or communications latency — is almost negligible.

How long does it take radio waves to reach Mars?

about 5 to 20 minutesIt generally takes about 5 to 20 minutes for a radio signal to travel the distance between Mars and Earth, depending on planet positions.

Related Articles:

• How Fast Do Radio Waves Travel In Space
• How Far Can Radio Waves Travel On Earth
• How Fast Do Asteroids Travel In Space
• How Fast Does Light Travel In Space
• How Fast Does Light Travel Through Space
• How Fast Do Rockets Travel In Space

Science Journalist

Science atlas, our goal is to spark the curiosity that exists in all of us. We invite readers to visit us daily, explore topics of interest, and gain new perspectives along the way.

You may also like

How To Increase Range Of Vex Robotics Controller

What Is Service Innovation And Design

Are There Software Development Platform For Robotics

Add comment, cancel reply.

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Recent discoveries

How Hard Is Intro To Robotics Csuf

Why Chemistry Is Called Central Science

What Is Calvin Cycle In Biology

What Was Louis Pasteur’S Major Contribution In Science

• Animals 3041
• Astronomy 8
• Biology 2281
• Chemistry 482
• Culture 1333
• Health 8466
• History 2152
• Physics 913
• Planet Earth 3239
• Science 2158
• Strange News 1230
• Technology 3625

Random fact

Investigators Link COVID-19 and Chance of Bloodstream Clot Formation