Chunky Salsa
kiwifarms.net
- Joined
- Jul 2, 2024
Because as the velocity of two points in space increases relative to each other, both of them to their own perspective have not gotten faster or slower in time. But both of them are under time dilation compared to each other. Both of these things are true; because there is no absolute frame of reference from which we can compare two points in space/time.
There isn't anything stopping you from building an infinitely rigid stick (aside from that very thing being impossible as that would make the speed of sound inside that rigid stick faster than the speed of light, which doesn't really work as the speed of light is less about the speed of a photon and more about a fundamental property of spacetime) and then prodding Tim The Alien in the head. The problem with that though is that compared to you, Mars is between 3 and 20 light minutes away. So let's assume Tim has built himself a equally infinitely rigid stick, and is pissed that some woman from Earth is jabbing him in the head. You jab Tim, he retaliates instantly. Both of you are viewing the other between 3 and 20 minutes into the past. Both of you are correct due to the lack of an absolute reference frame; so Tim could be jabbed in the head, look down his telescope and you see you getting ready to jab him in the head; and then poke you first. Tim has effectively time travelled to punch you in the head.
You can in theory go faster than the speed of light; there is no real 'rule' against this. But the way that we understand - and have demonstrated with GPS - relativity to work, means that doing so would result in things that seem to break causality. An FTL spaceship could go leave to another planet, and then come back to its point of origin before it ever even left.
