How to reconcile photon not experiencing time with it's travel time?

In summary: In summary, photons do not experience space-time and therefore cannot degrade or fray. They exist as quanta of energy and do not have properties such as time or a rest frame. Any interactions with matter-energy do not affect the photon itself, but may result in perturbations within the energy quantum. The concept of time does not apply to photons, as they do not have clocks and do not experience the passing of time. The idea of a photon decaying into other particles is not possible, as it would violate conservation principles such as energy, momentum, spin, and charge. Overall, it is not useful to think of photons as small lumps of matter, but rather as wave-like entities that can only be detected when interacting
  • #1
San K
911
1
If a photon does not experience space-time does that mean it cannot "degrade/fray"?

Is there a way to reconcile the, say, eight minutes, time
the photon (approx) took to travel from sun to Earth
with
the zero time that passed in the (frame of reference of) photon?

Where was the photon, in a sense, during those 8 minutes?
 
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  • #2
San K said:
If a photon does not experience space-time does that mean it cannot "degrade/fray"?
What does this mean ? Split ends ?

Is there a way to reconcile the, say, eight minutes, time the photon (approx) took to travel from sun to Earth with the zero time that passed in the (frame of reference of) photon?
There's nothing to reconcile. Photons ( if they exist at all in free space ) do not have clocks and don't care about time.
Where was the photon, in a sense, during those 8 minutes?
Where do you think it was ?

You can resolve all these questions using Maxwell's equations and if necessary, GR.
 
  • #3
To describe the world line of a photon, just use the coordinate time in some handy reference frame. That's all you need to know. A photon does not have a rest frame. (Is there an echo in here?)
 
  • #4
Mentz114 said:
What does this mean ? Split ends ?

thanks Mentz114

a photon is a quanta of energy, within that quanta, i guess, there could be perturbations.

i guess, those perturbations would be created/initiated/caused during the prior interaction of the photon with matter-energy.

however would these perturbations (within the photon) freeze in time-space, when the photon is, say, moving in a vacuum (and not interacting with anything)?
 
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  • #5
Mentz114 said:
Photons ( if they exist at all in free space )

Don't photons need to exist (in free space) so as to, say, reach from the sun to earth (while traversing the free space between the sun and earth)?
 
  • #6
San K said:
a photon is a quantum of energy, within that quantum, i guess, there could be perturbations.
This is quantum mechanics but photons have wavelength and possibly a polarization state - but no other properties. And the wavelength is frame dependent. It is not useful to think that photons can be treated as small lumps of matter. When you've seen one photon you've seen them all.

See this article http://en.wikipedia.org/wiki/Photon#Physical_properties

Don't photons need to exist (in free space) so as to, say, reach from the sun to Earth (while traversing the free space between the sun and earth)?
It is possible that photons only appear when light interacts with matter. In this case we can't say anything except that light goes from A to B. Maybe while it is in transit it is an em wave. But it is not crucial because we can't detect light unless it interacts with matter.
 
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  • #7
San K said:
If a photon does not experience space-time does that mean it cannot "degrade/fray"?
I think that conservation principles are more important for this. For a photon to decay into other particles those other particles would have to conserve energy, momentum, spin, charge, etc. It cannot decay into an electron because then it would violate conservation of charge. It cannot decay into an electron and a positron because then it would violate conservation of momentum. It cannot decay into a pair of photons because then it would violate conservation of spin. Etc.

San K said:
the zero time that passed in the (frame of reference of) photon?
We have had a rash of this question recently, and frankly I am getting tired of scratching. Here is the FAQ, please read through all of the other posts on the topic before continuing it here.

https://www.physicsforums.com/showthread.php?t=511170
 

1. How can a photon travel through space without experiencing time?

According to the theory of relativity, time is relative and can be affected by an object's speed and gravitational pull. Since photons travel at the speed of light, they experience time dilation, meaning time appears to stand still for them. Therefore, photons do not experience time in the same way as we do.

2. How is it possible for a photon to have a finite travel time if it doesn't experience time?

Although photons do not experience time, they still have a finite travel time. This is because time is a measurement of change, and photons do experience a change in position as they travel through space. Therefore, we can measure their travel time, even though they do not experience it.

3. Does this mean that photons can travel an infinite distance in an instant?

No, photons cannot travel an infinite distance in an instant. While they do not experience time, they still have a speed and cannot exceed the speed of light. This means that they can only travel a finite distance in a given amount of time, even though they do not experience time as we do.

4. How does the concept of time dilation apply to photons?

Time dilation is the phenomenon where time appears to pass slower for objects moving at high speeds. Since photons travel at the speed of light, they experience time dilation, meaning that time appears to stand still for them. This is due to the fact that as an object approaches the speed of light, its mass increases, and time appears to slow down for it.

5. Can we ever fully understand how photons experience time?

As humans, we experience time in a linear and constant manner. However, the behavior of photons is beyond our understanding, and it is difficult to comprehend how they experience time, or lack thereof. While we can study their behavior and make predictions, it is unlikely that we will ever fully understand how photons experience time.

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