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techstepgenr8tion
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19 Jul 2012, 4:21 pm

Are there any physics majors who have knowledge on the topic?

My question is essentially this: what does special relativity offer regarding photons and their ability to move in sine waves without a medium?

I'm curious as to what the evidence is that leans in this direction.

Thanks



jekenai
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20 Jul 2012, 7:36 am

Special relativity doesn't explain ability of light to exist without medium. The question is: Do we need to explain that?
It also doesn't tell anything about relation between wave and particle nature of micro-objects. That's the area of quantum theory.
And I wouldn't say that photons move in sine waves. I think you are imagining it wrong. But don't ask me how to imagine it right.



ruveyn
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20 Jul 2012, 9:36 am

techstepgenr8tion wrote:
Are there any physics majors who have knowledge on the topic?

My question is essentially this: what does special relativity offer regarding photons and their ability to move in sine waves without a medium?

I'm curious as to what the evidence is that leans in this direction.

Thanks


The photo electric effect is dead on corroboration of photons. If light were waves then the energy imparted to the electron in a metal would be proportional to the square of the amplitude of the wave. This is not the case. The energy transferred to ejected electrons is proportional to the frequency.

ruveyn



jekenai
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20 Jul 2012, 12:25 pm

ruveyn wrote:

The photo electric effect is dead on corroboration of photons. If light were waves then the energy imparted to the electron in a metal would be proportional to the square of the amplitude of the wave. This is not the case. The energy transferred to ejected electrons is proportional to the frequency.

ruveyn


The funny thing about light is, that it is waves. And it isn't. Photo effect is one of the reasons why it isn't waves. Interference is one of the reasons why it is. Light behaves a bit likes waves and a bit like particles, but it isn't either. We have some ideas what a particle is and what wave is. Light doesn't match them. We have problems imagining it because we can't see anything that acts like that.



physicsnut42
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20 Jul 2012, 9:29 pm

It IS an area of quantum mechanics. With every particle (like a photon) comes a wave. The wave tells us some probabilities about the particle's position and momentum, and somehow, it can interact and interfere with other probability waves. If you want to know about general relativity, though, don't ask quantum mechanics. the two contradict eachother very strongly, which is why everyone's all excited about GUT's and TOE's and string theory.
also, what i said may not have been 100% accurate (i'm not a physics major). if i got something wrong, i apologize.



Apple_in_my_Eye
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21 Jul 2012, 1:47 am

I think the OP's question is, does SR have anything to say about the "aether" not existing?

The possible answers would be:

1) SR reinforces the lack of the existence of the luminiferous aether.

or

2) SR has nothing to say about the matter.


My cognitive faculties are scrambled tonight, so I don't know the answer.

Er wait, maybe I can manage a coherent thought, here...

SR contains as an axiom that the speed of light is the same for all inertial observers (all non-accelerating observers, basically). So, I think that right there shoots down the aether.

That is, if you tried the Michelson-Morley experiment as a thought experiment and analyzed it from the POV of SR then M-M would give you a negative result.



jekenai
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21 Jul 2012, 5:49 am

MM experiment was one of the experiments that led to rejection of aether theory. MM experiment was also important because it was a strong hint for constant speed of light.

Apple_in_my_Eye wrote:
SR contains as an axiom that the speed of light is the same for all inertial observers (all non-accelerating observers, basically). So, I think that right there shoots down the aether.


Yes, I think that's right. The aether was defined as some privileged frame of reference, which doesn't exist in SR



ruveyn
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21 Jul 2012, 8:19 pm

Apple_in_my_Eye wrote:
I think the OP's question is, does SR have anything to say about the "aether" not existing?

The possible answers would be:

1) SR reinforces the lack of the existence of the luminiferous aether.

or

2) SR has nothing to say about the matter.


My cognitive faculties are scrambled tonight, so I don't know the answer.

Er wait, maybe I can manage a coherent thought, here...

SR contains as an axiom that the speed of light is the same for all inertial observers (all non-accelerating observers, basically). So, I think that right there shoots down the aether.

That is, if you tried the Michelson-Morley experiment as a thought experiment and analyzed it from the POV of SR then M-M would give you a negative result.


S.R. in no wise requires aether to carry light waves. The MMX settled the matter of luminiferous aether for good.

ruveyn



Apple_in_my_Eye
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21 Jul 2012, 8:42 pm

Yeah, but the OP's question was about what bearing SR had on the matter of the aether.



salem44dream
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21 Jul 2012, 8:47 pm

This probably sounds a little crazy, but I wonder if when they discover "gravitons," (if ever) there will be a lot of similarity between them and photons?



physicsnut42
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22 Jul 2012, 7:36 am

well, they're both massless particles... they just have different spins. It's entirely possible, likely, even.

Now what would be REALLY weird is if, somehow, they got the spin wrong, and photons were gravitons all along. Everyone would feel like complete idiots.

But it's unlikely that'll happen. They probably have the spin right.



Apple_in_my_Eye
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22 Jul 2012, 12:10 pm

One thing that photons & gravitons would have in common would be that they both obey Bose-Einstien statistics (meaning that more than can pile up into the same quantum states).



physicsnut42
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22 Jul 2012, 1:27 pm

oh yeah, that thing... is that the same as the pauli exclusion principle?



Apple_in_my_Eye
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22 Jul 2012, 2:01 pm

^ The exclusion principle is the complement to B-E statistics.

That is, particles are either bosons (integer spin), which follow B-E statistics,
or
fermions (half-odd integer spin) which follow Fermi-Dirac statistics, which is also known as the Exclusion Principle.



techstepgenr8tion
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23 Jul 2012, 9:51 am

ruveyn wrote:
Apple_in_my_Eye wrote:
I think the OP's question is, does SR have anything to say about the "aether" not existing?

The possible answers would be:

1) SR reinforces the lack of the existence of the luminiferous aether.

or

2) SR has nothing to say about the matter.


My cognitive faculties are scrambled tonight, so I don't know the answer.

Er wait, maybe I can manage a coherent thought, here...

SR contains as an axiom that the speed of light is the same for all inertial observers (all non-accelerating observers, basically). So, I think that right there shoots down the aether.

That is, if you tried the Michelson-Morley experiment as a thought experiment and analyzed it from the POV of SR then M-M would give you a negative result.


S.R. in no wise requires aether to carry light waves. The MMX settled the matter of luminiferous aether for good.

ruveyn
Apple did effectively nail the question behind my inquiry. The reason I ask; I see claims online that it isn't a closed case via M-M and that altitude has changed results suggesting that such a medium would float with the earths surface at ground level. I wanted to get more info from those who know a bit about this before taking anyone's word for it. Needless to say discovery of an aether could yield truly wild implications not to mention the potential for applied technology. I'm agnostic on the matter but just wanted an educated opinion check.



ruveyn
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23 Jul 2012, 12:36 pm

physicsnut42 wrote:
oh yeah, that thing... is that the same as the pauli exclusion principle?


Pauli exclusion applies only to fermions. Bosons love to pile up and congregate.

ruveyn