Re:Voyager 1 hears the hush of interstellar plasma
by Chris2048 on Tuesday May 11, 2021 @02:18PM
(#27121516)
> A spring under torsion is heavier than an unwound spring
Does it have more (invariant) mass?
Re:Voyager 1 hears the hush of interstellar plasma
by whatshisface on Tuesday May 11, 2021 @03:45PM
(#27122598)
Yes.
Ah, but it is. E=mc^2 is always true in the reference frame where the object is stationary. (We assume that we are co-moving with the windup car.) A spring under torsion is heavier than an unwound spring.