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Through which medium does light travel.


alt_f13

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Because things like Compton Scattering and electron diffraction occur, that can only be explained by a wave-like description.

 

IIRC Compton scattering is consistent with particle behavior.

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Neither a classical wave description or a classical particle description of light is fully adequate to describe light.

 

yes, exactly

 

Quote from kjitta: "I prefere to think of EM radiation as a stream of photons whos statistical behavoir assimilate wave properties."

 

i'm too lazy to go looking up papers right now but there have been experiments where one photon, or was it one electron, showed an interference pattern in a slit set-up

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yes' date=' exactly

 

Quote from kjitta: "I prefere to think of EM radiation as a stream of photons whos statistical behavoir assimilate wave properties."

 

i'm too lazy to go looking up papers right now but there have been experiments where one photon, or was it one electron, showed an interference pattern in a slit set-up[/quote']

 

I think it was one electron.

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yes' date=' exactly

 

Quote from kjitta: "I prefere to think of EM radiation as a stream of photons whos statistical behavoir assimilate wave properties."

 

i'm too lazy to go looking up papers right now but there have been experiments where one photon, or was it one electron, showed an interference pattern in a slit set-up[/quote']

 

Young's two slit experiment has been done both with single (that is only allowing one through the slits at any one time) electrons and single photons and even larger objects.

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Dictionary.com

wave: "A disturbance traveling through a medium by which energy is transferred from one particle of the medium to another without causing any permanent displacement of the medium itself. "

 

That's how I always think of waves... but I still cannot catch on to what a wave travels on if not particles.

 

How is the energy transfered? Sound, fine; coduction, fine; but light waves?

 

I don't know how else to phrase the question but I am not really getting the answer I want. I don't really care what light is, wave or not, I want to know what a wave is if not particles or a formulaic disturbance directly on some medium. How can you have a wave w/o a medium? (a wave being the definition above)

 

Is the answer "I don't know," or what?

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Dictionary.com

wave: "A disturbance traveling through a medium by which energy is transferred from one particle of the medium to another without causing any permanent displacement of the medium itself. "

 

That's how I always think of waves... but I still cannot catch on to what a wave travels on if not particles.

 

How is the energy transfered? Sound' date=' fine; coduction, fine; but light waves?

 

I don't know how else to phrase the question but I am not really getting the answer I want. I don't really care what light is, wave or not, I want to know what a wave is if not particles or a formulaic disturbance directly on some medium. How can you have a wave w/o a medium? (a wave being the definition above)

 

Is the answer "I don't know," or what?[/quote']

 

Dictionary.com is a reasonable source of information, but not an authority on technical matters.

 

Consider the possibility that the answer you "want" isn't correct. Light exhibits both wave and particle properties. It is through our experience with everyday items that we know what waves and particles are, but it is a mistake to assume that the quantum world behaves like the macroscopic world.

 

The waves are oscillations in electric and magnetic fields, which do not appear to need a medium to exist or propagate. If one is required, it doesn't have a density (or mass) or many other properties one might expect, that would distinguish it from "nothing."

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Dictionary.com is a reasonable source of information' date=' but not an authority on technical matters.

 

Consider the possibility that the answer you "want" isn't correct. Light exhibits both wave and particle properties. It is through our experience with everyday items that we know what waves and particles are, but it is a mistake to assume that the quantum world behaves like the macroscopic world.

 

The waves are oscillations in electric and magnetic fields, which do not appear to need a medium to exist or propagate. If one is required, it doesn't have a density (or mass) or many other properties one might expect, that would distinguish it from "nothing."[/quote']

 

The answer I 'want' is that "so called 'waves' are 'oscillations in electric and magnetic fields.'" But for there to be oscillations, there must be something to oscillate... particles perhaps? Strength of the field? What does frequency refer to when we are talking about EMR? This was the purpose of my original post. Insofar the question has *almost been answered. :eek:

 

[edit]

Yah, no, I wasn't looking for answers from dictcom. It just illustrated what I was getting at really well through the definition.

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The answer I 'want' is that "so called 'waves' are 'oscillations in electric and magnetic fields.'" But for there to be oscillations' date=' there must be something to oscillate... particles perhaps? Strength of the field? What does frequency refer to when we are talking about EMR? This was the purpose of my original post. Insofar the question has *almost been answered. :eek:

 

[edit']

Yah, no, I wasn't looking for answers from dictcom. It just illustrated what I was getting at really well through the definition.

 

The electric and magnetic fields oscillate, in accordance with Maxwell's equations. The frequency is the rate at which those fields oscillate.

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Alt, the wave definition you quote above is true for mechanical waves. Compression and relaxation of particles with mass, mass here being an important point. That is why sound energy is not transmitted through a vacuum. Photons have no mass, they are pure energy and that is how the energy is transported.

Once you stop comparing em radiation with mechanical waves you will maybe be able to answer your own question.

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Alt' date=' the wave definition you quote above is true for mechanical waves. Compression and relaxation of particles with mass, mass here being an important point. That is why sound energy is not transmitted through a vacuum. Photons have no mass, they are pure energy and that is how the energy is transported.

Once you stop comparing em radiation with mechanical waves you will maybe be able to answer your own question.[/quote']

 

Uhhuh. I just don't understand how a field can oscillate without anything changing...

 

And it doesn't, so what changes?

 

Oh and thanks for the explanation swansont. :rolleyes:

 

[edit]

I prefere to think of EM radiation as a stream of photons whos statistical behavoir assimilate wave properties.

 

I would aggree with this completely until someone starts up about light having wavelike properties as opposed to being photons.

 

That is where I have trouble with it. But it is still a very experimental area of science, so I don't believe there is a firm answer to this as of yet.

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I would aggree with this completely until someone starts up about light having wavelike properties as opposed to being photons.

 

That is where I have trouble with it. But it is still a very experimental area of science' date=' so I don't believe there is a firm answer to this as of yet.[/quote']

 

:confused: Very experimental? As in new and untested? Photon theory is nearly 100 years old, and the concept predates that by quite a bit.

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:confused: Very experimental? As in new and untested? Photon theory is nearly 100 years old, and the concept predates that by quite a bit.

 

So we must be in the advanced stages of physical understanding, and have ceased experimentation. :embarass:

 

No, not new and untested... Old and unproveable. We seem close to an answer, but while we have adequate explanations for what we can see, there is so much that we cannot see, it wouldn't take much to convince me that we know very little about the true nature of the universe; tip of the iceberg, so to speak... but that's a topic for another thread.

 

 

I'm still not clear on what oscillates in EM fields. Is it field strength?

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I stand by what I said.

 

Start a new thread if you want, and I'll join in.

 

[edit]

 

So we must be in the advanced stages of physical understanding, and have ceased experimentation.

 

=sarcasm

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So we must be in the advanced stages of physical understanding' date=' and have ceased experimentation. :embarass:

 

No, not new and untested... Old and unproveable. We seem close to an answer, but while we have adequate explanations for what we can see, there is so much that we [i']cannot[/i] see, it wouldn't take much to convince me that we know very little about the true nature of the universe; tip of the iceberg, so to speak... but that's a topic for another thread.

 

 

I'm still not clear on what oscillates in EM fields. Is it field strength?

 

Yes, the field amplitude, or strength, changes with time and position.

 

I don't think you'll get much argument that there's a lot we don't understand about the universe, but the nature of light is fairly well understood, and there isn't a lot of basic research going into it. Exotic stuff, yes.

 

I may be off base here, but it seems that you want a short and simple answer that meshes with everyday things that you observe with the naked eye - where waves are waves and particles are particles, and never the twain shall meet. QM isn't like that. But that doesn't mean it's not well understood.

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  • 5 years later...

My personal theory on this is that all areas of space is engulfed by an EM Field. Light therefore would simply be a small distortion in that field depending on the frequency. This would also be the reason that Radio waves, micro waves, and infrared travels through all of space and not just through areas with a visible or observable medium. This would also be the reason why light can be bent around gravity wells, which can be witnessed during a solar eclipse.

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My personal theory on this is that all areas of space is engulfed by an EM Field. Light therefore would simply be a small distortion in that field depending on the frequency. This would also be the reason that Radio waves, micro waves, and infrared travels through all of space and not just through areas with a visible or observable medium. This would also be the reason why light can be bent around gravity wells, which can be witnessed during a solar eclipse.

 

Are you familiar with the Luminiferous Aether?

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Yes I am quite familiar with the concept of aether but I'm not convinced especially since the results of several tests gave a negative result for the existence of aether.

 

What emperical evidence would differ between your idea and aether theory (which has be completely disproved).

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