Doesn't wavelength require a medium?

In summary, sound is represented by a wavelength due to the medium it is traveling through, but in light and other electromagnetic waves, the oscillations are of electric and magnetic fields which do not require a medium. The wavelength of a photon is the distance between electric and magnetic fields in one full cycle. Magnets do not curve photons, but they can curve the path of charged particles.
  • #1
Ghetalion
21
0
In audio, I've learned that sound energy are particles being compressed and rarified at specific rates, causing a "wave of pressure". Thus, sound is represented in a wavelength because of the medium it is "distorting"

My barely-elementary understandinf of QED makes me believe that in order for an electron to have a wavelength, it is attracted to the nucleus and repelled by antiparticle collisions between the electron and the nucleus. Is this true or did I misread something? Also, how can light traveling through a vacuum have a wavelength at all? Or is my definition of wavelength convoluted?
 
Physics news on Phys.org
  • #2
wavelength

So here is a problem that bothered scientists for a long time - how can light travel without a medium.

Well, its just that some waves require a medium for propagation and some don't. Those who do are called mechanical waves.

Let us take sound waves. They require a medium because they travel by oscillations of the praticles of the medium. But in light ( and other electromagnetic waves ) the oscillations are of Electric and Magnetic fields which don't require a medium at all. Although they can travel in machanical mediums.

I am not sure about what varies in an electron but I think it is the probability of finding it at a certain position.

spacetime
www.geocities.com/physics_all/index.html
 
  • #3
After Maxwell and before Einstein's photon, physicists thought they had a good handle on how light could propagate without a medium; there were the electric and magnetic fields (you could visualize "lines of force" a la Faraday if it helped you) and changes in one generated changes in the other, in accordance with Maxwell's equations. So the changes would propagate, and the equations said the propagation would travel at a number which, based on measurements, looked very close to the measured speed of light. This was simple and natural, and IT IS STILL AVAILABLE. Although Maxwell EM is now just an effective theory, it is still valid in its range of application, and though the electrowweak sector of the standard model has a much more difficult version of the subject, that version has to be captured at a certain level of detail by the old view. Engineers working with wave guides can "see" (very clearly measure) the electric and magnetic maxes coming down the pipe.
 
  • #4
So, does that explain how Einstein may still call them an "ether" (from another thread)? The fields are a medium for the propagation of light, its just that its self-creating/sustaining and not tied to anything else? Just trying to get my arms around the concept... I'm picturing a wave on a string that carries the string with it.
 
Last edited:
  • #5
I see... so the wavelength of a photon is really it's interchanging magnetic and electric fields?
 
  • #6
It would be the distance from an electric maximum (and magnetic minimum) through the next magnetic maximum and on to the next electric maximum agin. One full cyle of the fields.
 
  • #7
Interesting. So does this mean that when a photon with an extremely long wavelength passes a magnet, that will will not curve as sharp as a photon with an extremely short wave length?
 
  • #8
I don't think anyone said magnets curve photons. Magnets are known to curve the path of charged particle. A photon is not a charged particle, it is another field, an oscillating one. Nothing in EM theory predicts photon deflection if it crosses another field.
 

FAQ: Doesn't wavelength require a medium?

1. What is the relationship between wavelength and medium?

Wavelength refers to the distance between two consecutive peaks or troughs in a wave. It is determined by the frequency of the wave, which is the number of cycles per second. A medium is any substance or material that a wave travels through. The wavelength of a wave does not require a medium to exist, but the medium does affect the speed at which the wave travels.

2. Can a wave have a wavelength without a medium?

Yes, a wave can have a wavelength without a medium. For example, electromagnetic waves such as light and radio waves can travel through a vacuum, which is not a medium. The wavelength of these waves is determined by their frequency and does not require a medium to exist.

3. How does the medium affect the wavelength of a wave?

The medium through which a wave travels can affect the velocity of the wave, which in turn affects its wavelength. For example, in a denser medium such as water, the velocity of a wave is slower compared to air. This results in a shorter wavelength in water compared to air for the same frequency of the wave.

4. Does the wavelength of a wave change when it travels through different media?

Yes, the wavelength of a wave can change when it travels through different media. As mentioned earlier, the velocity of a wave is affected by the medium it is traveling through, which in turn affects its wavelength. The frequency of the wave remains constant, but the wavelength can change as it travels through different media.

5. Is there a limit to the wavelength of a wave in different media?

There is no limit to the wavelength of a wave in different media. The wavelength of a wave can be as short as the size of an atom or as long as several kilometers, depending on the frequency and the medium it is traveling through. However, the medium can affect the maximum wavelength that a wave can have, as seen in the case of sound waves, where the wavelength cannot be longer than the distance between two molecules in a medium.

Back
Top