Does this connect Quantum Theory and Special Relativity?

[QuantumTheoryThinker]

This is probably extremely wrong I just want to know how. If photons don't experience time doesn't that mean they are every where at once, and if that is true doesn't part of quantum physics say before a particle is observed its in all the states it can be in? So doesn't that apply in that sense since connecting special relativity and quantum theory in some way? Btw I'm not even learning this in school yet for probably a couple of years so I'm probably extremely wrong.

 

[PeterDonis]

If photons don't experience time

This is not correct. A better way of saying it is that the concept of "experiencing time" doesn't make sense for photons.

doesn't that mean they are every where at once

No.

 

[A. Neumaier]

If photons don't experience time doesn't that mean they are every where at once

They are everywhere at once in the direction of flight only. The transversal position is well-defined as it commutes with the momentum in the direction of flight.

 

[PeterDonis]

They are everywhere at once in the direction of flight only

I don't think this is correct. Different events on a null worldline are distinct; even though proper time cannot be used as an affine parameter along a null worldline, there are other affine parameters that can be used, and each event on the worldline has a distinct value of the affine parameter. It is true that there is not a well-defined "position operator" for a photon, but that's not the same as saying it's "everywhere at once".

 

[A. Neumaier]

I don't think this is correct. It is true that there is not a well-defined "position operator" for a photon, but that's not the same as saying it's "everywhere at once".

Of course saying it is ''everywhere at once'' is an interpretation issue, but you cannot say it is not correct since one cannot disprove it without making philosophical assumptions. it is at least as correct as saying that a photon is a particle.

In fact, it is a very good visualization for the physical properties, as it explains in an effortless way why we perceive the whole boundary of the past light cone as our present.

In addition, according to the uncertainty principle, a completely well defined frequency means (in the limit of a massive particle with exceedingly tiny mass, where a position operator is still well-defined) a completely well-defined longitudinal momentum and hence a completely undetermined longitudinal position .

 

[PeterDonis]

you cannot say it is not correct since one cannot disprove it without making philosophical assumptions

Perhaps a better wording than "correct" would be "not useful for this discussion".

In fact, it is a very good visualization for the physical properties, as it explains in an effortless way why we perceive the whole boundary of the past light cone as our present.

But it also invites the incorrect inference that the entire boundary of our past light cone is our present. The information coming to us from our past light cone is not "present" information; it is out of date, and how out of date it is varies according to how far "back" in our past light cone it is (where "back" here means "how different the value of the appropriate affine parameter is compared to its value at our current event"). So I still don't think that this viewpoint is useful.

according to the uncertainty principle, a completely well defined frequency means (in the limit of a massive particle with exceedingly tiny mass, where a position operator is still well-defined) a completely well-defined longitudinal momentum and hence a completely undetermined longitudinal position .

This is true, but the OP did not talk about photons with a completely precise frequency. It just talked about photons.

 

[PeterDonis]

On consideration, I have changed the level of this thread from "I" to "B", given the OP's apparent background. @QuantumTheoryThinker , I suspect that most of the responses given so far have been somewhat over your head. However, more information about exactly what level of school you are in would help.

 

[A. Neumaier]

The information coming to us from our past light cone is not "present" information; it is out of date, and how out of date it is varies according to how far "back" in our past light cone it is

This is again a question of interpretation.

How far out of date it is according to your definition is frame dependent, and by going to a nearly infinite momentum frame, you can make any point on the past light cone almost vanishingly little out of date. Being not covariant, your notion of ''out of date'' is unphysical and therefore

"not useful for this discussion"

 

[PeterDonis]

How far out of date it is according to your definition is frame dependent

Yes, fair point.