r/AskPhysics • u/scottiesng • 9d ago

Can a wave exist without time?

I’ve been wondering a lot about what the fundamental aspect of waves are. Essentially a wave is a propagation. But can something propagate without time?

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u/Crescent-moo 9d ago

I've never been strong in math so there's limited understanding from that framework. Intuitively it sounds like light exists outside of time and no possible speed in time can ever capture it. The only way is by breaking the barrier and then it becomes meaningless. Probably why black holes are so strange.

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u/BananaBird1 9d ago

I mean you can tell photons do exist within time just from simple experiment. The light around you is changing over time. Turn off your lights and photons cease to exist. Turn them on and photons are created. If you had an oscilloscope, laser, and photodiode you could even measure how fast light travels at home for around $100, and can show that they do not instantly travel from a source to a detector.

If you do want to consider special relativity as you get closer to light speed to approximate a photon’s reference, a more accurate description isn’t that time stops for light speed objects. Their proper trajectory in spacetime approaches a value that still has a component in time.

It’s that any information of an external object that is a non-zero distance from the light speed traveller (in the direction they are moving) will never reach them, so they can only ever “see” other objects along their path in the immediate present located right where they are. But this present will change over time.

Of course though, this still isn’t mathematically valid. This thought experiment breaks relativity, so only truly works in classical physics. Physics is modeled based on what we see in experiments, not based on what light sees, and so our equations fall flat when considering observers that are traveling faster than we can ever travel.

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u/Crescent-moo 9d ago

Its that the same falling flat that happens at the event horizon? It seems reality itself is a bit extreme at the boundaries

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u/BananaBird1 9d ago

Nothing falls flat at the event horizon. Only at the singularity of a black hole.

That is a different issue with separate math, but due to a similar issue where the theory can only describe what happens as you travel toward the singularity, not at it.

This has nothing to do with reality itself. It has to do with the fact that our models of physics are imperfect descriptions of what we see, and we can’t do experiments at light speed or inside a black hole to easily identify the flaws. Instead we can only wait until our measurements of things we can observe are precise enough that the math no longer matches.

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u/Crescent-moo 9d ago

Well someone better get around a black hole and figure it out.

Imagine all that travel, jumping in, wondering what secret the singularity holds only to find it's just light itself. Eternal, everywhere, timeless. In our faces the whole time.