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Offline yor_on

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Re: what is the nature of a photon ?
« Reply #25 on: 11/03/2013 16:50:14 »
I don't expect it to shift energy myself?
But if you instead went out to measure a same sun, shining on all those planets, being of a same distance to them. Would you now expect the energy to be different between planets?

And remember that this is quite lose definitions from me, they are not very strict, because with different mass you also should be able to expect different definitions of 'clocks' and 'rulers' when comparing between any and each of them. Meaning that I avoid those strict definitions :) Yes, I'm a coward..
==

Another way of looking at it might be that, if uniform motion equalize any other uniform motion, no matter what mass you're in, while measuring that light bulb inside that black box. Then I don't see how it can matter? Because if mass mattered for this experiment we would only have a equivalence between the same amount of mass in a uniform motion, as it seems to me.
==

Then again, this one is really interesting simplified. If I was to define it from some smallest point instead, I'm not sure what position I would take? The one I'm presenting is how I got it, but?
« Last Edit: 11/03/2013 17:24:47 by yor_on »
 

Offline simplified

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Re: what is the nature of a photon ?
« Reply #26 on: 11/03/2013 17:54:20 »
Probably Einstein had Great gravitational field,which was fastly moving the Earth to him...
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #27 on: 11/03/2013 18:05:29 »
From my side it's about what a 'frame of reference' should mean, from scaling. If we were to use some small definition I would use Plank scale, but that one is not really measurable, so we need to go up in scale. We can measure on electrons and atoms though. And then you have HUP there too. But we have a definition of being 'at rest' with something as defining when you are in a same 'frame of reference'. So, am I, or am I not at rest with that light bulb, on Earth, measuring a energy from it? To you I'm not, right? But according to how I get it, I am, macroscopically defined. Maybe Pete can clear this one out?
=

And yes, it has to do with the gravity locally measured. Do that introduce different 'frames of reference' relative being 'at rest' with different mass. If it does you should be correct and we should be able to measure different energies, being inside that 'black box'. If it doesn't then my assumption should be correct. And as it all goes back to a light quanta, propagating in a gravitational field, we will have to introduce some sort of interaction with gravity's 'energy' as I think, ignoring the geodesic, using your definition. And as that means a intrinsic clock to me?
« Last Edit: 11/03/2013 18:30:42 by yor_on »
 

Offline simplified

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Re: what is the nature of a photon ?
« Reply #28 on: 11/03/2013 18:18:20 »
I don't know what is space-time.Can it define what is at rest?
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #29 on: 11/03/2013 18:35:14 »
The one you don't think exist heh :)
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #30 on: 11/03/2013 18:43:45 »
SpaceTime, to me, is about clocks and rulers. Those get their definition from 'c' as a constant speed of light in a flat space (a vacuum containing no resistance, no gravity, and SR), relative mass, 'relative motion', and accelerations (becoming GR). And I think that should be it? Or is there something I'm missing?

Gravity being a preferred direction to me.
==

Well, actually there is. Shows you that you better think, before you act (never been that good at that:)

Light is only defined as being 'c', relative a inertial observer, finding no inertia acting on him (no acceleration). If light speed instead was based on pure emissions, no matter where they took place, GR wouldn't be here. Because then it wouldn't matter if there was a acceleration or not, light would still be 'c' as measured from any observer.

A modern redefinition of this is to take into consideration the way uniform accelerations and gravity is equivalent, and so define it as 'c' relative gravity, acting on the geodesic (path) of the light. This one may be of interest Einsteinís Investigations of Galilean Covariant Electrodynamics prior to 1905. 
==

The thing is that I keep forgetting stating the differences between SR and GR. To those of you old enough to have read it from Einsteins direct thoughts, or having a good physics background, that is important, and it should be to me too, but I forget :) Senility ahoy.


« Last Edit: 11/03/2013 21:29:37 by yor_on »
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #31 on: 11/03/2013 19:07:57 »
From that a ideal definition of being 'at rest' should be co-moving in a flat SpaceTime, shouldn't it? Or in a 'same gravitational potential'. And that's a question of what scales would mean for it, to me? And I'm still wondering about that one.
 

Offline Pmb

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Re: what is the nature of a photon ?
« Reply #32 on: 11/03/2013 20:42:34 »
Hmm :)

. If you fall with the gravity, the gravity disappear for you.
No,that doesn't.Gravity increases my energy.
He's correct. If you're in a uniform gravitational field and you're in free fall then you're frame of reference is for all practical purposes an inertial frame of reference with no field present. That's exactly why Einstein said that you can transform away a gravitational field.
 

Offline lightarrow

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Re: what is the nature of a photon ?
« Reply #33 on: 11/03/2013 22:42:05 »
Quote from: lightarrow
Why a photon can't be deflected?
First off Iím restraining my discussion to special relativity (SR). In SR there is nothing that interacts with a photon that can deflect it. As I recall it, and I may e wrong, I donít consider Compton scattering to be deflecting the photon since a photon is destroyed when it hits the electron and a new one produced. Otherwise the photon canít be deflected as an electron is i.e. via the electric field. No such field for deflecting photons exit that Iím aware of,
Ok. If a photon cannot be deflected, which is the utility of talking about the "relativistic mass of the photon"? It corresponds to its energy (via multiplicative constant) and there isn't any other context in which you use it.
Quote

Quote from: lightarrow
Let's say that you are right about relativistic mass of a photon: the formula E = mc2, with m as the relativistic mass, is correct for photons only, not for tardyons.
That is incorrect. Some people even define relativistic mass as m = E/c2.

It can be shown that if p = mv where m = relativistic mass then it can be shown that E = mc[sup[2[/sup]. Iíve derived that relationship here - http://xxx.lanl.gov/abs/physics/0308039

Of course, but if you remembere we were talking of the fact longitudinal and transverse relativistic masses are different so the equation E = mc2 is however wrong for non stationary bodies, because you can't use it for both cases at once.
 

Offline simplified

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Re: what is the nature of a photon ?
« Reply #34 on: 12/03/2013 16:57:28 »
Hmm :)

. If you fall with the gravity, the gravity disappear for you.
No,that doesn't.Gravity increases my energy.
He's correct. If you're in a uniform gravitational field and you're in free fall then you're frame of reference is for all practical purposes an inertial frame of reference with no field present. That's exactly why Einstein said that you can transform away a gravitational field.
My free fall slows down my time.Einstein was wrong.What is uniform gravitational field at free fall?
« Last Edit: 12/03/2013 17:11:03 by simplified »
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #35 on: 12/03/2013 17:53:18 »
Are you thinking that if you're in a free fall under gravity, you're still in a gravitational field?
Then you have another definition of it than Einstein had Simplified, and you will need to make it a proposition that covers most any situation relativity takes up. And the point there is that it need to fit relativity, at least those parts we have measured directly, or indirectly, as muons. So you need your idea to cover, for example, why muons can go further than their allowed 'time' if measured at rest. And as they are particles of mass we find them to exist measurably. Read that paper I linked and use it to test your ideas.
 

Offline simplified

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Re: what is the nature of a photon ?
« Reply #36 on: 12/03/2013 18:32:50 »
Are you thinking that if you're in a free fall under gravity, you're still in a gravitational field?
Then you have another definition of it than Einstein had Simplified, and you will need to make it a proposition that covers most any situation relativity takes up. And the point there is that it need to fit relativity, at least those parts we have measured directly, or indirectly, as muons. So you need your idea to cover, for example, why muons can go further than their allowed 'time' if measured at rest. And as they are particles of mass we find them to exist measurably. Read that paper I linked and use it to test your ideas.
Who did make experiment "muon at free fall"?I thought I said that my free fall slows down my time.
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #37 on: 12/03/2013 20:06:57 »
So you define it such as a free fall, following a geodesic slows down time locally? Ok, then do you define it such as with different uniform motions you get different 'time'? And do you define it relative the gravity?

If you do, then inside a 'black box', deep space with no tidal forces, can you prove that gravitational field? By some local experiment inside that black box. And how will you prove a motion? No windows, no outside peeking. Inside, by a experiment.
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #38 on: 12/03/2013 20:22:30 »
And do you expect different uniform motions to change your experiments inside that black box. Uniformly moving following a 'geodesic' in a gravitational field (free fall)
 

Offline Pmb

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Re: what is the nature of a photon ?
« Reply #39 on: 12/03/2013 23:38:09 »
Sorry lightarrow but I've discussed relativistic mass until I was blue in the face. I won't discuss it again. I've already said everything that can be said in that article that I wrote on the subject. I wrote it so I wouldn't have to keep repeating the same old explanation over and over and over again. If you disagree with it then so be it. If it isn't in there then I have nothing to say about it. Every question that could be asked on the subject is addressed in that paper. There's no reason for me to ay anything else on the subject. If nobody wants to read it then they really don't want to know what I have to say about it. Plain and simple. :)
« Last Edit: 12/03/2013 23:53:18 by Pmb »
 

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Re: what is the nature of a photon ?
« Reply #40 on: 13/03/2013 02:07:02 »
Although I'm loathe to get into one of those infernal discussions about the definition of mass I will say this. One has to be careful about when the relationship P = mU where m = proper mass, P = 4-momentum and U = 4-velocity. Suppose you have an ion in an electric field. This relationship doesn't hold because it doesn't take into account the inertia of the stress imposed in the ion due to the electric field.
 

Offline simplified

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Re: what is the nature of a photon ?
« Reply #41 on: 13/03/2013 12:15:28 »
So you define it such as a free fall, following a geodesic slows down time locally? Ok, then do you define it such as with different uniform motions you get different 'time'? And do you define it relative the gravity?

If you do, then inside a 'black box', deep space with no tidal forces, can you prove that gravitational field? By some local experiment inside that black box. And how will you prove a motion? No windows, no outside peeking. Inside, by a experiment.
Gravitational mass is energy which creates gravitational field.Gravitational interaction exists  even in the black box.I can measure all gravitational mass in the black box.I can create motionless clock and moving clock inside the box.Using exact measurements ,smart scientists can calculate changing external factor of my slowing of time inside the black box. :P
« Last Edit: 13/03/2013 12:26:36 by simplified »
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #42 on: 13/03/2013 14:23:51 »
Yes, I think you can, using light as your clock, maybe splitting it relative a rotating mirror, and using a interferometer. What will that tell you inside your black box about motion? When it comes detecting that gravitational field, you either have to assume that this will create a detectable motion inside your box, or? That you're not 'moving' at all.

In relativity that uniform motion or geodesic only are described as detectable relative another frame of reference though. A acceleration is something else, detectable locally as a blue or/and red shift, depending on which way you measure in relation to the light source, and your accelerations direction. Well, as I think of it.
 

Offline simplified

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Re: what is the nature of a photon ?
« Reply #43 on: 13/03/2013 15:48:56 »
Yes, I think you can, using light as your clock, maybe splitting it relative a rotating mirror, and using a interferometer. What will that tell you inside your black box about motion? When it comes detecting that gravitational field, you either have to assume that this will create a detectable motion inside your box, or? That you're not 'moving' at all.

In relativity that uniform motion or geodesic only are described as detectable relative another frame of reference though. A acceleration is something else, detectable locally as a blue or/and red shift, depending on which way you measure in relation to the light source, and your accelerations direction. Well, as I think of it.
There experimental measurements with atomic clocks do not coincide with usual  calculatings.
From your own source the photons ,which have passed through a mirror labyrinth, have blue shift. :)
« Last Edit: 13/03/2013 16:31:13 by simplified »
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #44 on: 13/03/2013 20:09:28 »
Do you mean the Michelson-Morley experiment? That was about finding a aether. The assumption was that as the light went different ways, the original light split into two parts, when it joined after going around, it would show to become out of phase. Out of phase with each other would mean that the light had found some 'resistance' due to a aether. But it didn't matter, that light was still in phase, same as when it was sent out. But it should work, as I think, to find a 'preferred motion' inside that box too. The other way is to measure some light source(s) set up inside that box, why not the middle of it, and then try to find blue and red shifts relative your position, measuring the light.



 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #45 on: 13/03/2013 20:39:32 »
The point is that the Pound and Rebka gravitational red and blue shifts measured in a stairwell at Harvard in 1959 is about the observer measuring between frames of reference, just as Nist found clocks to tick differently at different height. But you moving in a uniform motion, without resistance, in space, becomes moving 'with the gravity's preferred direction'. you don't have any 'frames of reference' inside to measure against. You are 'at rest' with gravity, as well as 'at rest' with the box, and the light source, no matter from where you measure it, inside that box.  That is a classical 'black box experiment'/ thought experiment.
==

Or put this way, as long as your feet are firmly placed on the ground, you're not 'at rest' (relative gravity). Then you will find frames of reference. In a free fall (read geodesic) it becomes different. There is no 'gravity' inside that black box, and without that?
=

And it's not really fruitful to think of geodesics as being some sort of equivalence to magnetic field lines. We can assume the lightbulb, placed in the middle of that black box, to send out 'photons' in a sphere formed direction from it.

And all of those 'paths' must be geodesics in a uniform motion, per definition.
« Last Edit: 13/03/2013 21:31:28 by yor_on »
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #46 on: 13/03/2013 21:27:25 »
Wanna make it real weird :)

Imagine a really big black box, uniformly moving in a gravitational field. So inside it we have no gravity, then imagine yourself accelerating a smaller black box, containing a happy race of dwarfs, measuring a light bulb inside that.

Now we have one big black box, containing no gravity, which inside it have a smaller black box, uniformly constantly accelerating, finding a gravity.

So what is gravity?
=

Now add another smaller box (steered by the proud race of hitchhiker mice) relative the 'small box'. It accelerates inside it, but in the opposite direction, taking out the acceleration the 'small box' use, relative the big one.

So, can we define that as being 'still', relative what? And, if we do, can we define it as being 'at rest' with big box?
And, if we do, are then both of those boxes, the smallest and biggest, now equivalent?

Uniform motion :)
Accelerations

and relative motion.

heh.
« Last Edit: 13/03/2013 22:58:06 by yor_on »
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #47 on: 13/03/2013 22:15:13 »
Let's do it the other way.

Assume that you can measure different uniform motions (locally measured).
Will 'c' survive that?

'c' is defined relative a inertial observer uniformly moving in a geodesic.
A geodesic is a definition of a 'path of no resistance/gravity' locally, relative both the space and the gravity.
So wherever there is a geodesic there must be 'gravity'.

Space can't be flat, it can possibly be unmeasurable, but gravity has a infinite reach.
That means that you can't state. 'Well, gravity ends here.'

So if you want 'absolute motion' instead of 'relative motion', which means that you must be able to differ 'uniform motions' inside black box measurements, you destroy the definition of 'c' too. Because with absolute motion you must introduce a very strange idea of emissions of light always being at 'c', no matter how we find that uniform motion (inertial observers) to differ from another, measuring in that black box.

Can you see how I think there? Just as with the box in the box above, we now can assume that two boxes, one inside another and with both being in different 'uniform motion', must be related to some absolute frame of reference, defining a 'real' uniform velocity/geodesic/speed.

And that one would be even weirder than the one we have, as it seems to me. As both boxes must find 'c' in a two way experiment. So what would 'c' be a constant relative if so?
=

and remember that we define space as homogeneous and isotropic. Meaning that space should look much the same, viewed from any position, looking at mass distributions relative space. When using uniform motions as 'relative' and 'equivalent' you can define them 'at rest'. All uniform motions becoming the exact same relative 'c'. Using 'absolute motions' that statement must be wrong.

And? what the he* is 'c' then a constant relative? Because we can measure it to exist in any uniform motion, in a two way experiment? It's not theoretical.
« Last Edit: 13/03/2013 23:05:39 by yor_on »
 

Offline simplified

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Re: what is the nature of a photon ?
« Reply #48 on: 14/03/2013 00:34:36 »
Travel of the photons in the labyrinth takes some time.The same time makes you and your black box approach to the big mass.In closer space to gravitational object photons have more energy. :P
« Last Edit: 14/03/2013 09:04:01 by simplified »
 

Offline yor_on

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Re: what is the nature of a photon ?
« Reply #49 on: 14/03/2013 01:35:28 »
:)

Ahem, think it's your turn to present arguments Simplified.
Just use your logic to show me how you think it is done.
And try to be as clear as you can so we get how you think there.
 

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Re: what is the nature of a photon ?
« Reply #49 on: 14/03/2013 01:35:28 »

 

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