Photons and Special Theory of Relativity ?

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Offline lenadorap

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Photons and Special Theory of Relativity ?
« on: 25/11/2011 03:56:07 »
If photons travel at the speed of light, a clock in a photon shall be stand-still. If it is stand-still photon shall not change or undistructable. How this could be explained?

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Offline Soul Surfer

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Photons and Special Theory of Relativity ?
« Reply #1 on: 25/11/2011 08:32:32 »
The fact that time does not pass for a photon does not mean that a photon cannot be created or destroyed.  from its "point of view"  it is just created and then destroyed whether it lasted  a picosecond or most of the age of the universe during its life from our point of view.
« Last Edit: 25/11/2011 08:34:48 by Soul Surfer »
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Offline JP

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Photons and Special Theory of Relativity ?
« Reply #2 on: 25/11/2011 14:14:39 »
Also, the usual idea that time doesn't pass for a photon is wrong.  Time doesn't actually stand still for a photon according to our theories.  The idea that time slows down for objects that move fast only applies to those with mass, which can never move at the speed of light.  We don't know how to describe the "point of view" of light itself. 

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Offline Soul Surfer

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Photons and Special Theory of Relativity ?
« Reply #3 on: 25/11/2011 18:45:40 »
Agreed JP,  Strictly the point of view of a photon or any fundamental particle does not make much sense but photons only change when they interact nonlinearly and are either absorbed or changed in energy so there are no real points of reference.
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Offline imatfaal

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Photons and Special Theory of Relativity ?
« Reply #4 on: 25/11/2011 19:08:41 »
we can posit, theorise, and experiment on single electrons - so I think the FoR of some elementary particles makes a lot of sense; the massless ones I agree not, and the tricksy ones that are never found in isolation perhaps it would be better not to, and I guess now that the neutrinos are all superluminal (I know it is still unconfirmed) we have to be careful about them; and the ew bosons and the mu and the tau last less time than its worth bothering about ... perhaps you are right after all :-)
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Offline simplified

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Photons and Special Theory of Relativity ?
« Reply #5 on: 26/11/2011 18:52:26 »
Photon has kinematic time of motion.

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Offline yor_on

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Photons and Special Theory of Relativity ?
« Reply #6 on: 26/11/2011 19:34:30 »
You mean in its annihilation?

You won't see a photon anywhere, except in its release of 'energy' dying, as I understands it. But as we also seem to assume that waves can 'reflect' elastically, changing 'momentum' (direction) but not 'kinetic energy'?

It most definitely should be a duality.
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Offline simplified

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Photons and Special Theory of Relativity ?
« Reply #7 on: 27/11/2011 13:30:46 »
You mean in its annihilation?

You won't see a photon anywhere, except in its release of 'energy' dying, as I understands it. But as we also seem to assume that waves can 'reflect' elastically, changing 'momentum' (direction) but not 'kinetic energy'?

It most definitely should be a duality.
No. I can know way and speed. And at all maybe photon is small tornado in gravitational field of universe. [:P]
« Last Edit: 27/11/2011 13:34:02 by simplified »

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Offline yor_on

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Photons and Special Theory of Relativity ?
« Reply #8 on: 27/11/2011 21:23:13 »
I don't agree there Simplified, you can deduce a path, but not 'know' it. It's enough comparing it to a balls path to see the difference there. And all deducing involves statistical approaches, as far as I know. You can only measure a photon once, in its annihilation. That you can define them as being 'identical' of property and then assume that by measuring a large amount coming from a same source, at different positions, do not give you a photons path, as various 'slit experiment' also can show you, depending on interpretation.
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Offline simplified

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Photons and Special Theory of Relativity ?
« Reply #9 on: 29/11/2011 14:39:59 »
I don't agree there Simplified, you can deduce a path, but not 'know' it. It's enough comparing it to a balls path to see the difference there. And all deducing involves statistical approaches, as far as I know. You can only measure a photon once, in its annihilation. That you can define them as being 'identical' of property and then assume that by measuring a large amount coming from a same source, at different positions, do not give you a photons path, as various 'slit experiment' also can show you, depending on interpretation.
I think you confuse different waves.
Photon has quantum wave.Such wave is  wave in a narrow corridor of travel.

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Offline yor_on

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Photons and Special Theory of Relativity ?
« Reply #10 on: 29/11/2011 23:03:40 »
"According to the wave model of light, the speed of the electrons should be related to the intensity of the light. But that's not what happens. In reality the speed of the electrons depends only on the frequency of light, and the light intensity determines the number of electrons that fly off." (photoelectric effect.)

As for if a photon is a 'quantum wave'? Don't know, but I doubt it. A photon is not a wave, it is a quanta of energy.
« Last Edit: 29/11/2011 23:06:40 by yor_on »
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Offline simplified

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Photons and Special Theory of Relativity ?
« Reply #11 on: 30/11/2011 14:50:40 »

Then quanta of energy of electron is photon. Does it travel at 'c'?

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Offline yor_on

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Photons and Special Theory of Relativity ?
« Reply #12 on: 30/11/2011 22:43:54 »
yes, if you are talking about a 'photon', not a electron.
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Offline simplified

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Photons and Special Theory of Relativity ?
« Reply #13 on: 01/12/2011 13:33:00 »
yes, if you are talking about a 'photon', not a electron.
Can electron have quanta of energy? What is quanta of energy?

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Offline JP

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Photons and Special Theory of Relativity ?
« Reply #14 on: 01/12/2011 16:31:49 »
Quantum states are often defined in terms of quantized values: physical quantities such as energy, momentum, position, angular momentum, and so on that take on only discrete values.  You can't generalize to all particles about what values get quantized, but for each type of particle and situation there are rules. 

Photons are, by definition, the smallest quanta of energy you can get from an electromagnetic field of a given frequency.  If I shine a green laser at you, the green photons that make it up are the tiniest possible piece of energy you can pick out of that beam.  Because they are defined as energy quanta, they do not have a simple description in terms of how they spread out over space, so you can't properly draw a photon wave traveling through space.

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Offline simplified

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Re: Photons and Special Theory of Relativity ?
« Reply #15 on: 19/12/2011 14:57:39 »
Quantum states are often defined in terms of quantized values: physical quantities such as energy, momentum, position, angular momentum, and so on that take on only discrete values.  You can't generalize to all particles about what values get quantized, but for each type of particle and situation there are rules. 

Photons are, by definition, the smallest quanta of energy you can get from an electromagnetic field of a given frequency.  If I shine a green laser at you, the green photons that make it up are the tiniest possible piece of energy you can pick out of that beam.  Because they are defined as energy quanta, they do not have a simple description in terms of how they spread out over space, so you can't properly draw a photon wave traveling through space.
Can you properly draw a corridor of travel of photon in space?
« Last Edit: 19/12/2011 14:59:13 by simplified »

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Offline JP

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Re: Photons and Special Theory of Relativity ?
« Reply #16 on: 19/12/2011 15:02:57 »
No.  Photons don't follow classical paths through space.

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Offline simplified

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Re: Photons and Special Theory of Relativity ?
« Reply #17 on: 19/12/2011 15:38:05 »
No.  Photons don't follow classical paths through space.
Then I don't understand why shadows of objects can be predicted?  :D

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Offline yor_on

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Re: Photons and Special Theory of Relativity ?
« Reply #18 on: 19/12/2011 15:56:35 »
There are different approaches Simplified. Some do want to see it as one path, but that isn't how the experiments I know of describe it. But all agree in that the source (laser) and the sink (detector) are connected, and they also, like Feynman's interference or otherwise, leave only one path existing as the defined outcome. And it's those 'final' paths that then defines the shadow you cast.
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Offline JP

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Re: Photons and Special Theory of Relativity ?
« Reply #19 on: 19/12/2011 16:48:26 »
No.  Photons don't follow classical paths through space.
Then I don't understand why shadows of objects can be predicted?  :D

You can predict where billions of photons will go, or where a photon interacting with matter (a photon in an optical fiber, for example) will go.  But you can't predict the path taken by a true photon (meaning one that is described as the smallest packet of energy of an electromagnetic field). 

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Offline simplified

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Re: Photons and Special Theory of Relativity ?
« Reply #20 on: 19/12/2011 16:54:10 »
There are different approaches Simplified. Some do want to see it as one path, but that isn't how the experiments I know of describe it. But all agree in that the source (laser) and the sink (detector) are connected, and they also, like Feynman's interference or otherwise, leave only one path existing as the defined outcome. And it's those 'final' paths that then defines the shadow you cast.
Then your astronomers can predict an eclipse only after this event. ;)

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Offline JP

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Re: Photons and Special Theory of Relativity ?
« Reply #21 on: 19/12/2011 17:06:33 »
There are different approaches Simplified. Some do want to see it as one path, but that isn't how the experiments I know of describe it. But all agree in that the source (laser) and the sink (detector) are connected, and they also, like Feynman's interference or otherwise, leave only one path existing as the defined outcome. And it's those 'final' paths that then defines the shadow you cast.
Then your astronomers can predict an eclipse only after this event. ;)

Simplified, there is no problem with making predictions if intensity by averaging over enormous numbers of photons. 

If the sun released only one photon, they couldn't predict the eclipse.

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Offline simplified

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Re: Photons and Special Theory of Relativity ?
« Reply #22 on: 20/12/2011 16:15:52 »
There are different approaches Simplified. Some do want to see it as one path, but that isn't how the experiments I know of describe it. But all agree in that the source (laser) and the sink (detector) are connected, and they also, like Feynman's interference or otherwise, leave only one path existing as the defined outcome. And it's those 'final' paths that then defines the shadow you cast.
Then your astronomers can predict an eclipse only after this event. ;)

Simplified, there is no problem with making predictions if intensity by averaging over enormous numbers of photons. 

If the sun released only one photon, they couldn't predict the eclipse.
You try to prove undefiniteness  by another undefiniteness. Let know a finding of a concrete source (we should know a solar point which will radiate the one photon).
I can not agree with you because don't know the experiments,which prove you are right. :-'(

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Offline imatfaal

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Re: Photons and Special Theory of Relativity ?
« Reply #23 on: 21/12/2011 17:21:56 »
Simplified

i. we can and do predict eclipses (you cannot find fault with our ability to do that)
ii. using the sun as a source for a single photon is a bonkers idea (you are the person raising the idea that we must be able to reduce the sun to a singular source - it isn't, and we don't try to make it so)
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Offline simplified

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Re: Photons and Special Theory of Relativity ?
« Reply #24 on: 21/12/2011 19:39:54 »
Simplified

i. we can and do predict eclipses (you cannot find fault with our ability to do that)
ii. using the sun as a source for a single photon is a bonkers idea (you are the person raising the idea that we must be able to reduce the sun to a singular source - it isn't, and we don't try to make it so)
I thought Yor_on and JP were serious. :I

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Offline Bill S

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Re: Photons and Special Theory of Relativity ?
« Reply #25 on: 29/12/2011 16:39:42 »
Quote
I thought Yor_on and JP were serious.

You lost me there, Simplified, just when I thought I'd kept a handle on the thread. :(

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Offline Bill S

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Re: Photons and Special Theory of Relativity ?
« Reply #26 on: 29/12/2011 18:09:08 »
Quote from: JP
Time doesn't actually stand still for a photon according to our theories.

Could we have some more information about these theories, please.

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Offline imatfaal

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Re: Photons and Special Theory of Relativity ?
« Reply #27 on: 30/12/2011 10:29:55 »
Quote from: JP
Time doesn't actually stand still for a photon according to our theories.

Could we have some more information about these theories, please.

The time standing still is an extrapolation of SR - but it is not really a correct one. 

SR uses the formula [tex]\Delta T_{prime}=\frac{\Delta T}{\sqrt{1-\frac{v^2}{c^2}}[/tex]

For a massive object as it approaches c the bottom of the fraction will approach zero - and time dilation will become more and more pronounced when viewed from a local FoR in relative rest.  It might seem for an outside observer that time has completely stopped as an object reaches c - but SR is quite clear on the fact that a frame of reference of the photon or any other massless particle which must be travelling at c is not defined (you need to be able to define an inertial frame where the photon is at rest and that is a nono), you cannot just extrapolate that equation.
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Offline simplified

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Re: Photons and Special Theory of Relativity ?
« Reply #28 on: 30/12/2011 15:08:10 »
Quote
I thought Yor_on and JP were serious.

You lost me there, Simplified, just when I thought I'd kept a handle on the thread. :(
You were lost earlier. They tried to prove probable inability of the moon to block a way of a visible photon(length of wave has meaning) even by central part . :P
« Last Edit: 30/12/2011 15:20:13 by simplified »

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Offline JP

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Re: Photons and Special Theory of Relativity ?
« Reply #29 on: 30/12/2011 15:50:16 »
I suggest you reread what we were describing, simplified.  You keep thinking of photons as "little bullets," which they aren't.

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Offline simplified

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Re: Photons and Special Theory of Relativity ?
« Reply #30 on: 02/01/2012 18:29:17 »
I suggest you reread what we were describing, simplified.  You keep thinking of photons as "little bullets," which they aren't.
If we do not know height of photon wave then what creates an eclipse? Diameter of the Moon (parallel to a way of a photon) or diameter of the Moon (perpendicular to way of  photon)? :-\

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Offline JP

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Re: Photons and Special Theory of Relativity ?
« Reply #31 on: 02/01/2012 18:37:09 »
I'm not an expert on QED, so I can't go into too much detail on photons, but they're derived by looking at what are called plane waves.  Plane waves extend over all space, so they aren't little bullets.  A plane wave in itself might not be particularly physical (after all an infinitely wide and long wave isn't coming out of the sun), but by writing a combination of plane waves, you can generate physical sources, such as the sun.  Similarly, photons don't have simple bullet-like trajectories that you can trace from the sun to the earth, but the combination of many photons acting together does generate these trajectories. 

Its weird and nonintuitive, but that's quantum mechanics.

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Offline simplified

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Re: Photons and Special Theory of Relativity ?
« Reply #32 on: 02/01/2012 18:58:58 »
The simple question is too complex(difficult) for the backward science. :D

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Offline JP

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Re: Photons and Special Theory of Relativity ?
« Reply #33 on: 02/01/2012 21:25:47 »
The simple question is too complex(difficult) for the backward science. :D

Nope.  But if you aren't willing to put effort into understanding it, it's not worth trying to explain it further!  *<;o)

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Offline Phractality

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Re: Photons and Special Theory of Relativity ?
« Reply #34 on: 02/01/2012 23:59:22 »
If photons travel at the speed of light, a clock in a photon shall be stand-still. If it is stand-still photon shall not change or undistructable. How this could be explained?
As a moving clock passes a succession of observer's clocks (which are stationary and synchronized in the observers reference frame) the time difference between the moving clock and each successive observer's clock will change. The moving clock's time will advance more slowly than the time on successive observer's clocks.

The closer a clock's relative speed is to the speed of light, relative to the observer's reference frame, the slower that clock appears to be compared to the succession of observer's clocks that it passes. A clock is a mechanism made of matter. Matter cannot move as fast as light. Even if a clock is moving at .99999999999999999999999999999999999999 c relative to an observer, a photon will still pass that clock at the speed of light in the clock's reference frame. It doesn't even matter which dirction the photon is moving in the clock's reference frame, the speed of the photon is always the same. So it makes no sense to talk about a clock moving along with a photon. The speed of the photon is always the same relative to any clock.
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Offline LetoII

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Re: Photons and Special Theory of Relativity ?
« Reply #35 on: 18/01/2012 04:09:09 »
i think its not an ultimate standstill, its a different level of speed hard to imagine for us humans. for now