I’m asking this because there is a scifi book I’m reading, and in the book there’s a scene where someone is communicating with a person in a spacecraft moving at lightspeed. I know their ability to communicate would probably not be possible, but let’s just put that aside for a second. Hypothetically, if you could communicate with someone moving lightspeed, would the time dilation make it so that they would appear to be moving and speaking very slowly relative to you?


Assume a spherical cow in a vacuum
An infinite, frictionless vacuum?
Is there any other kind for spherical cows to populate?
Now I’m trying to image how spherical cows, or really anyone, can reproduce in a frictionless vacuum.