[Nevermark]

> You cannot decay if you don’t experience time.

Interesting take! But if photons couldn't decay due to not experiencing time, they couldn't do anything else either.

The reality is that a photons creation and destruction are not prohibited, but simply "experienced" as two events at different locations at the same time, with the photon being the "thing" that connects those events.

Given that interpretation, it might be reasonable to assume that all photons have beginnings and ends, regardless of the duration we perceive between them, or they wouldn't exist.

Time being no barrier at all for photons.

[nyrikki]

From a photons perspective, emition and absorption are simultaneous.

While from our perspective it is a form of causal connection, that is mearly due to the frame of reference.

While we can infer the connection between each, it is possibly better to consider the speed of light as the speed of causality.

But as there are no privileged reference frames under GR the choice is yours.

But from the photons perspective, it doesn't experience time at all so it can't be a barrier.

But don't confuse the map for the territory. GR is a model, not the system itself.

The fact that almost every test we can figure out has only confirmed it doesn't change that.

Under the 'all models are wrong but some are useful' idea, in GR photons not experiencing time is important to that model.

[pixl97]

>But if photons couldn't decay due to not experiencing time, they couldn't do anything else either.

I mean we are jumping way out of the classical behavior that objects like you and I exist in. To the photon itself is a timeless object. It 'moves' in a null geodesic where t=0. Attempting to apply any classical behavior that occurs in time-like objects just isn't going to work when applying them to massless light-like objects.

[supportengineer]

Would that seem like a fold in spacetime to the photon?

[Nevermark]

I can't top the sibling comment about a summer breeze! But it is an interesting question.

Not only does the photon not experience any delay between its two end points, but it experiences its path between them as a simple shortest-distance straight line segment, even if the same path looks like a curve through gravitationally warped space-time to us.

The photon does experience a form of distance, i.e. the number of wave lengths between its ends. But just the number of cycles, not the actual wave lengths which we would see varying as we experienced dark energy and space stretching the photon's wavelength from our viewpoint.

So a photon "experiences" two spacially separated ends, and a number of wave cycles between them, and that's it? Perhaps.

[nick7376182]

Probably more like a summer breeze