The speed of light is a fundamental aspect of space-time. Time isn't separate from space-time, it is bound up with space into space-time. And then if you goof the rules, goofy things happen.
If you look down in the cousin comments to yours, I had already posted a comment making it clear that I don't think light propagates instantly (3 minutes to Mars and all that).
It's certainly possible that someone will come up with a theory that allows us to set aside the idea of space-time, but it's not worth worrying about until it happens.
Think of it this way: photons don't have to exist, they might just be a model for the propagation of information. In the reference frame of a photon, propagation is instantaneous.
To be clear, you are saying if someone can make it to mars in under three minutes, they can kill their younger self because of the laws of physics that say "if you goof the rules, goofy things happen" ?
To get to Mars in less than 3 minutes you have to either convert mass into energy and back or invent entirely new physics. It'd be pretty cool if either of those things happen.
Specifically, in response to a question about why FTL breaks causality, I said "To get to Mars faster than light, you have to be able to travel backwards in time."
The implication there is actually that you can't go faster than light.
If you went to Mars in 1 minutes instead of 3 you would be going faster than light but not going backwards in time. I'm not sure where you are getting that from.
Like if Mars is reachable by travel though space in one minute, that reachable Mars is inextricably in the past of the Earth that you start from.
If you don't travel through space, then you literally have the ability to jump between points in space-time and are sort of obviously traveling through time.
Like if Mars is reachable by travel though space in one minute, that reachable Mars is inextricably in the past of the Earth that you start from.
Nope, you are mixing up philosophy with science and math.
If you don't travel through space, then you literally have the ability to jump between points in space-time and are sort of obviously traveling through time.
The speed of light is a fundamental aspect of space-time. Time isn't separate from space-time, it is bound up with space into space-time. And then if you goof the rules, goofy things happen.
If you look down in the cousin comments to yours, I had already posted a comment making it clear that I don't think light propagates instantly (3 minutes to Mars and all that).
It's certainly possible that someone will come up with a theory that allows us to set aside the idea of space-time, but it's not worth worrying about until it happens.
Think of it this way: photons don't have to exist, they might just be a model for the propagation of information. In the reference frame of a photon, propagation is instantaneous.