system
Given the following post, respond as if you're commenting on Reddit:
human
The Earth goes around the Sun which goes around the Milky Way which is hurtling through space.  I was told that in physics, as velocity increases, time slows down.  Is time moving slower for us than for a hypothetical stationary observer in interstellar space?

Is time passing differently in different solar systems and in different galaxies?  Is there a 'universal time' in which a certain defined amount of time has elapsed since The Big Bang?
gpt
There isn't a "universal time." All inertial reference frames are equivalent. You could say that Earth is hurling at 99.9999% the speed of light in some direction, and you wouldn't be wrong.

If you choose to ignore all that, you can pick a reference frame in which the cosmic microwave background is the same temperature in all directions. Relative to this, we are moving about 600 km/s. In terms of time dilation relative to this frame, the difference is only about two parts per million.