system
Given the following post, respond as if you're commenting on Reddit:
human
Do radioactive elements decay at the same rate if said elements are traveling near the speed of light?
gpt
Good question.  They decay at the same rate *in the reference frame that they are at rest.*  This means that to an outside observer who sees the element going really fast, the decay happens much slower due to time dilation.

This is a well observed phenomena; cosmic muons have observed lifetimes that are quite a bit longer than the relatively slower ones we can get in a lab.