Do all photons have equal energy?

[derek w]

No, that doesn't count. You have changed your reference frame when you do that; energy is not an invariant quantity.

But my original question was do all photons have equal energy in 4 dimensional space-time?

 

It's the 4 dimensional space that changes not the photon?

Edited March 26, 2013 by derek w

[swansont]

But my original question was do all photons have equal energy in 4 dimensional space-time?

 

It's the 4 dimensional space that changes not the photon?

 

Space-time is already 4-dimensional. Photons do not all have equal energy.

[beefpatty]

Do you possibly mean 4 spatial dimensions and one time dimension?

[derek w]

Do you possibly mean 4 spatial dimensions and one time dimension?

Yes,you have hit the nail on the head there.

(w,x,y,z) + t

 

r² = w² + x² = wavelength/4

 

where r = radius

and w = 0 is a point of equilibrium

Edited March 26, 2013 by derek w

[beefpatty]

My gut reaction is that if the photon is entirely (or partially) polarized in the 4th space dimension we would notice some energy missing in our 3 dimensions. I'm not sure what your equation is supposed to represent, could you explain it further?

[swansont]

What radius?

[ACG52]

In which way would a photon change it's momentum,it can't change it's velocity and it can't change it,s mass.

 

It can change it's energy.

[juanrga]

In which way would a photon change it's momentum,

 

For instance via Compton scattering, the photon changes its momentum [math]p_\gamma \to p_{\gamma'}[/math] due to collision with an electron at rest. The electron final momentum [math]p_{e^-}[/math] is the difference between the final and the initial momenta of the photon (the law of conservation of total momentum holds)

 

[math]p_\gamma - p_{\gamma'} = p_{e^-}[/math]

 

it can't change it's velocity and it can't change it,s mass.

 

The Newtonian expression [math]p=mv[/math] is only valid for a massive free particle moving at non-relativistic speed. The photon is both massless and relativistic. For a photon [math]p_\gamma=h\omega/c[/math] with [math]\omega[/math] the frequency.

Edited March 26, 2013 by juanrga

[derek w]

What radius?

Question? does a photon go through a cycle of existence e.g:- from one point existing as an electron through a point of non-existence to a point of existence as a positron and then non-existence and back to electron?

[swansont]

Question? does a photon go through a cycle of existence e.g:- from one point existing as an electron through a point of non-existence to a point of existence as a positron and then non-existence and back to electron?

 

No

[derek w]

If I have 4 spacial dimensions(w,x,y,z) then an electron and positron can occupy the same position in 3 dimensions but different positions in 4 dimensions,

(w-r,0,0,0) and (w+r,0,0,0) thereby have mass but no electric charge(a wimp/dark matter).only if the electron and positron oscillate on the x,y,or z axis,would they have a detectable charge.And only if they have enough kinetic energy would they separate.

[beefpatty]

I think I see where you're going with this. What makes the 4th spatial dimension special i.e., why is only an overlap in our three dimensions enough to cause annihilation? What happens if they overlap in all four dimensions? What determines a scattering event isn't the overlap in some the dimensions but the overlap in all of them, which is easily generalized to any number of spatial dimensions you want. If there were a fourth spatial dimension, then we would expect there to be collisions where a scattering event should have happened in our three dimensions but didn't because the particles missed each other in the fourth dimension. What I'm getting at is we should see cross sections that deviate from theory (namely that are lower than what theory predicts), which we don't.

[swansont]

We don't observe this happening. The Pauli exclusion principle works in 3 spatial dimensions.

[derek w]

If 2 like charged particles are heading towards each other,the 2 particles radiate photons towards each other therefore pushing them apart,however if 2 opposite charged particles(electron/positron) are heading towards each other they must radiate photons outward until the electron and positron occupy the same space.

We don't observe this happening. The Pauli exclusion principle works in 3 spatial dimensions.

Does the pauli exclusion principle apply to electron and positron occupying the same space?

[swansont]

No, it would apply to 2 electrons, but space doesn;t suddenly become 4D when a positron makes an appearance. Or are you claiming that it does?

[derek w]

Can mass be explained with 3 dimensions?

[elfmotat]

Can mass be explained with 3 dimensions?

 

What do you mean by "explained?"

[derek w]

What do you mean by "explained?"

modelled.

[ACG52]

Substituting one vague word for another does not help.

[elfmotat]

modelled.

 

This whole thread is very strange. Of course you can "model" mass in any number of dimensions. It's just a scalar.

[derek w]

No, it would apply to 2 electrons, but space doesn;t suddenly become 4D when a positron makes an appearance. Or are you claiming that it does?

The vacuum would be 3 dimensional,particles would be 4 dimensional ripples.

[swansont]

The vacuum would be 3 dimensional,particles would be 4 dimensional ripples.

 

Then your hypothesis is proved wrong. Electrons obey Pauli exclusion in 3D. A fourth dimension would make them distinguishable, so they wouldn't have to obey it. i.e. a proposed fourth dimension carries with it the prediction that electrons wouldn't obey Pauli. They do. Back to the drawing board.

[elfmotat]

 

Then your hypothesis is proved wrong. Electrons obey Pauli exclusion in 3D. A fourth dimension would make them distinguishable, so they wouldn't have to obey it. i.e. a proposed fourth dimension carries with it the prediction that electrons wouldn't obey Pauli. They do. Back to the drawing board.

Why would an additional dimension make electrons distinguishable? I can't think of any good reasons.

[Przemyslaw.Gruchala]

Then your hypothesis is proved wrong. Electrons obey Pauli exclusion in 3D. A fourth dimension would make them distinguishable, so they wouldn't have to obey it. i.e. a proposed fourth dimension carries with it the prediction that electrons wouldn't obey Pauli. They do. Back to the drawing board.

 

Electrons have the same electric charge = same charged particles are repelling. Without any other reasons such as Pauli exclusion needed.

[swansont]

Why would an additional dimension make electrons distinguishable? I can't think of any good reasons.

 

Exchangeable is a better word. You can't have two electrons in the same place, but if there was a fourth dimension, they could be separated by their fourth-dimensional coordinate. IOW their wave functions would not be identical in 4D, even though they were in 3D.

 

Electrons have the same electric charge = same charged particles are repelling. Without any other reasons such as Pauli exclusion needed.

 

Completely beside the point.