system
Given the following post, respond as if you're commenting on Reddit:
human
Would people who live on different planets age at different rates if one planet moves through space faster than the other?
gpt
Technically yeah, but nothing you can live on actually goes fast enough to matter much. Generally, galaxies move relative to each other at hundreds to thousands of km/s. Stars orbit the galaxy at hundreds of km/s. Rogue stars, ejected from galaxies (aka "hypervelocity stars") go at like a thousand or so km/s as well.

At even 3,000 km/s, i.e. 1% of the speed of light, time dilation is like a factor of 0.005%. That's like half an hour per year, which is certainly measurable, but it's not like they're experiencing an hour for every year we live on Earth or whatever.

There are things that go *really* fast in space, but they're not solid objects. Jets of plasma ejected from the intense magnetic fields in the gas around black holes can go above 99% of the speed of light. So those particles would age at a dramatically slower rate - they would experience radioactive decay much slower for instance. But this is a super hot and very low density jet of plasma - there's not like planets and stars getting shot out that fast.