Hacker News new | ask | show | jobs
by this_was_posted 1101 days ago
unless the body it rotates around rotates at the exact same speed around another body in the opposite direction
1 comments

Then it still rotates.
It can only rotate relative to an arbitrary point, not in some objective absolute sense. Here it does not rotate relative to chosen point.
Something about privileged reference frames...
But what's the alternative, right?