Does a Photon Experience Time or Space During Travel?

[Stephanus]

Not only the proton is never at rest. It always travels at the speed of light.
It just hits me.
1. Proton is not time like or space like. It's light light. Is this true?
2. Proton is not time like, so it has no proper time. Is this true?
3. Proton is not space like, so it has no proper distance. Is this true?

I assume you mean "photon". Yes, a photon is lightlike, not timelike or spacelike. (More precisely, a photon's 4-momentum, the 4-vector that describes it, is lightlike.)

What?? I typed PROTON four times??

The concept of "proper time" only applies to timelike objects, so yes, it doesn't apply to a photon.
The concept of "proper distance" only applies to spacelike intervals, so yes, it doesn't apply to a photon, since a photon's worldline is null (lightlike).
According to whatever inertial frame we are using. Photons themselves are lightlike, but you can certainly describe their trajectories using inertial frames. The concepts of "proper time" and "proper distance" don't apply along a photon's worldline, but with respect to any inertial frame (i.e., with respect to any timelike observer), photons do take time to travel and cover distance while traveling.

I "suspected" that much.
I already knew that:
Timelike events has proper time, no proper distance.
Spacelike events has proper distance, no proper time.
I just realized that, PHOTON wl is not time like, but it's not spacelike either.
Never tought about "light ray" in space time diagram.
I hope there's no silly typo this time!

[Add]

1. Proton is not time like or space like. It's light light. Is this true?

Did I type "lightlight"? Supposed you already knew that it's light like

 

[Stephanus]

According to whatever inertial frame we are using.

Oh.

Photons themselves are lightlike, but you can certainly describe their trajectories using inertial frames.

And it's always 45⁰ degree right?

The concepts of "proper time" and "proper distance" don't apply along a photon's worldline, but with respect to any inertial frame (i.e., with respect to any timelike observer), photons do take time to travel and cover distance while traveling.

Yes.

 

[PeterDonis]

And it's always 45 degree right?

In a standard spacetime diagram in flat spacetime, yes.