[omarchowdhury]

Every single comment you've written on this subject closes all discussion on it. So what is there to discuss? Or shall I remain silent in the ignorant darkness of my status as a (physics) layman?

Even Einstein inserted an anthropomorphized frame of reference into the thought experiments of the celestial objects he contemplated, to explain to others. If we can't ask questions about photons in relation to spacetime as we know it, then what questions can we ask? We certainly don't know spacetime as photons "know" it, since its not "well defined."

Interestingly still, you use the term worldline to describe the totality of the temporal-spatial existence of a photon, so clearly there are concessions to be made and all this is more defined than you assert... and you're lightly reproving us for not using the same dictionary as you...

I'm interested in this subject but not interested enough (or rather, have the time and energy) to become a physicist to understand, if that's what you're going to ultimately suggest to get even a dim, but accurate understanding of the nature of light.

[pdonis]

> Every single comment you've written on this subject closes all discussion on it

I have done no such thing. I have only closed discussion based on a fallacious premise. If you drop the fallacious premise there is plenty to discuss.

> We certainly don't know spacetime as photons "know" it, since its not "well defined."

I did not say spacetime is not well-defined. Spacetime is not "as photons know it" or as any observer "knows" it. Spacetime is the underlying geometric entity; it requires no "point of view" to exist, or even to be described; you can describe spacetime without ever using inertial frames, which are what your "points of view" actually are.

> you use the term worldline to describe the totality of the temporal-spatial existence of a photon

That's because "worldline" is the standard physics term for it, as used in physics textbooks and peer-reviewed papers.

> you're lightly reproving us for not using the same dictionary as you.

If you want to discuss physics, it helps a lot to use the standard language of physics.

> I'm interested in this subject but not interested enough (or rather, have the time and energy) to become a physicist to understand

You don't have to become a physicist. But you do have to be willing to drop fallacious premises.

[SAI_Peregrinus]

Just note that however you try to define "the photon's frame of reference" you end up with a division by zero, so the definition becomes meaningless.

Eg distance traveled is 0 due to length contraction. Time taken is 0 due to time dilation. So what's its velocity? 0/0 = undefined, the question is meaningless. But the velocity is arguably more fundamendal than the distance travelled or time taken, so those aren't truly 0. They're also undefined quantities.