Sabine Hossenfelder Explains the Block Universe
Sabine Hossenfelder · Explainer · YouTube title: Does the Past Still Exist?
Why it's here
HN commenters share it as a clear explanation of the block universe and relativity of simultaneity.
What it covers
Sabine Hossenfelder explains how special relativity leads to the block universe, in which past, present and future all exist equally, and asks what that means for whether the past still exists.