# Does the photon even exist from its own perspective?

From its perspective, can't it "see" itself as being at rest while everything else is moving at c? Then, from its perspective it's massless AND not moving, so it doesn't have mass OR momentum and thus has no energy at all. Also, doesn't time stop from the photon's perspective? If an object has no mass, no momentum, no energy and does not experience time, then how can it even be said to exist at all? If it doesn't exist from its own perspective, how can it exist from ours?

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ZapperZ
Staff Emeritus
From its perspective, can't it "see" itself as being at rest while everything else is moving at c? Then, from its perspective it's massless AND not moving, so it doesn't have mass OR momentum and thus has no energy at all. Also, doesn't time stop from the photon's perspective? If an object has no mass, no momentum, no energy and does not experience time, then how can it even be said to exist at all? If it doesn't exist from its own perspective, how can it exist from ours?
If you look at the Lorentz tranformation, can you tell me what happens when you let v=c?

Now, after you do that and notice something funny, it should tell you "Wait a second, our laws don't work so well at v=c", which means that your extrapolation of what we know and love into that regime may not be kosher. Since we can't do that simply, it implies that you conclusion (or guess work) of what is going on in the photon's frame is moot.

Zz.

If you look at the Lorentz tranformation, can you tell me what happens when you let v=c?

Now, after you do that and notice something funny, it should tell you "Wait a second, our laws don't work so well at v=c", which means that your extrapolation of what we know and love into that regime may not be kosher. Since we can't do that simply, it implies that you conclusion (or guess work) of what is going on in the photon's frame is moot.

Zz.
Good idea. I have never done the Lorentz Transformation but I looked it up and it seems like you will get stuff involving 1/0 if you try this so apparently that won't work - like you said. Didn't know that. That's pretty cool. It does indeed tell me that we have more to learn. Thanks.

From the photon's point of view the travel time doesn't exist. It is emitted then the next instant it is absorbed. Even if it needs to travels to another galaxy, from it's perspective it takes the same time as going an inch, which is no time at all.

From the photon's point of view the travel time doesn't exist. It is emitted then the next instant it is absorbed. Even if it needs to travels to another galaxy, from it's perspective it takes the same time as going an inch, which is no time at all.
What happens when it bounces off a cosmic particle without being absorbed? From your perspective on how the photon behaves, I would gather that you have not accounted for this event, unless you think it acts as if it is re-emitted at an angle theta. Please advise.

rcgldr
Homework Helper
From the photon's point of view the travel time doesn't exist. It is emitted then the next instant it is absorbed. Even if it needs to travels to another galaxy, from it's perspective it takes the same time as going an inch, which is no time at all.
IMO, since photons have frequencies, there are a countable number of cycles between emission and absorbtion, so using it's own frequency as it's internal clock, a photon would be "aware" of the passage of time.

IMO, since photons have frequencies, there are a countable number of cycles between emission and absorbtion, so using it's own frequency as it's internal clock, a photon would be "aware" of the passage of time.
I can't grasp the meaning of this phrase.

Dale
Mentor
IMO, since photons have frequencies, there are a countable number of cycles between emission and absorbtion, so using it's own frequency as it's internal clock, a photon would be "aware" of the passage of time.
A photon's frequency is not an intrisic property of the photon, but depends on the frame of reference. I don't think it is correct to say that a photon has it's "own" frequency.

DaveC426913
Gold Member
Photons do not have a frame of reference. It is meaningless to talk about passage of time or of a photon's FoR.

Photons do not have a frame of reference. It is meaningless to talk about passage of time or of a photon's FoR.
I may disagree to a point. Given that photons do exist, they must subsequently have some describable identity, which so far has been the frame of reference of the human. If we take the Newtonian idea which describes the world from the point of view of the subject as opposed to Relativity which supports objective viewpoints (points of view from outside the subject), we may be able to construct a frame of reference that relates a photon to its external surroundings rather than the reverse. What it seems is being described, is a Newtonian viewpoint as an object-in-itself, which seems to run into difficulties when the external world is encountered as I previously noted, when a photon bounces off a cosmic particle.

If the path of the photon is properly constructed, I see no reason why a virtual frame of reference, cannot be idealized in this manner.

jtbell
Mentor
This is metaphysical speculation, not physics.