What is the angular speed limit, like linear speed limit is c?

phydev
Messages
20
Reaction score
0
what is the angular speed limit, like linear speed limit is c??

does there exist an angular speed limit, just like we have 'c' in relativistic mechanics?
If Yes, How?
If No, Why?
 
Physics news on Phys.org


phydev said:
does there exist an angular speed limit, just like we have 'c' in relativistic mechanics?
If Yes, How?
If No, Why?

At the simplest level, it depends on radius. Radius * angular speed < c is required. I doubt there is any other fundamental (rather than practical) limit.
 


phydev said:
does there exist an angular speed limit, just like we have 'c' in relativistic mechanics?
If Yes, How?
If No, Why?

Well, obviously no tangential velocity can exceed that of light. The maximum angular velocity would therefore depend on the radius of rotation. So, to answer your question, yes and no; there exists a maximum angular velocity which is determined by radius of rotation, but it is not fundamental the way c is.
 


so should it be c/R?? (as I was expecting!)
 
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...
From $$0 = \delta(g^{\alpha\mu}g_{\mu\nu}) = g^{\alpha\mu} \delta g_{\mu\nu} + g_{\mu\nu} \delta g^{\alpha\mu}$$ we have $$g^{\alpha\mu} \delta g_{\mu\nu} = -g_{\mu\nu} \delta g^{\alpha\mu} \,\, . $$ Multiply both sides by ##g_{\alpha\beta}## to get $$\delta g_{\beta\nu} = -g_{\alpha\beta} g_{\mu\nu} \delta g^{\alpha\mu} \qquad(*)$$ (This is Dirac's eq. (26.9) in "GTR".) On the other hand, the variation ##\delta g^{\alpha\mu} = \bar{g}^{\alpha\mu} - g^{\alpha\mu}## should be a tensor...

Similar threads

Back
Top