Stresses in a rotating object?

  • Thread starter Thread starter billyboy
  • Start date Start date
  • Tags Tags
    Rotating
billyboy
Messages
2
Reaction score
0
Has anyone considered the following. If I have a really big disc and rotate it at a certain angular velocity. Then at some distance from the centre the tangential speed of the disc will equal the speed of light and any distance beyond will have a speed greater than that of light. Obviously this cannot be the case and some strange time dilation and length contraction effects will take place. Can anyone explain exactly what does happen? Presumably some stresses are set up in the disc which could be calculated?
 
Physics news on Phys.org
OK, so this has bugged me for a while about the equivalence principle and the black hole information paradox. If black holes "evaporate" via Hawking radiation, then they cannot exist forever. So, from my external perspective, watching the person fall in, they slow down, freeze, and redshift to "nothing," but never cross the event horizon. Does the equivalence principle say my perspective is valid? If it does, is it possible that that person really never crossed the event horizon? The...
In this video I can see a person walking around lines of curvature on a sphere with an arrow strapped to his waist. His task is to keep the arrow pointed in the same direction How does he do this ? Does he use a reference point like the stars? (that only move very slowly) If that is how he keeps the arrow pointing in the same direction, is that equivalent to saying that he orients the arrow wrt the 3d space that the sphere is embedded in? So ,although one refers to intrinsic curvature...
So, to calculate a proper time of a worldline in SR using an inertial frame is quite easy. But I struggled a bit using a "rotating frame metric" and now I'm not sure whether I'll do it right. Couls someone point me in the right direction? "What have you tried?" Well, trying to help truly absolute layppl with some variation of a "Circular Twin Paradox" not using an inertial frame of reference for whatevere reason. I thought it would be a bit of a challenge so I made a derivation or...

Similar threads

Replies
18
Views
1K
Replies
14
Views
2K
Replies
8
Views
2K
Replies
4
Views
2K
Replies
42
Views
727
Replies
10
Views
2K
Replies
80
Views
14K
Back
Top