How Does the Curvature of Space Affect Our Perception of Gravity?

  • Thread starter Thread starter PrincePhoenix
  • Start date Start date
  • Tags Tags
    Space
PrincePhoenix
Gold Member
Messages
116
Reaction score
2
In many places (here in forums and on a few documentaries) when talking about relativity, it is often said to consider the space like a piece of cloth,fine net etc. If we think of it that way, shouldn't everything be on the same level in space? And then why do people on South Pole feel gravity towards the centre of the earth? Because space is being curved beneath them.Please forgive me if I'm missing something very basic.
 
Physics news on Phys.org
That's taking the analogy too far, in my opinion.
 
hamster143 said:
That's taking the analogy too far, in my opinion.

Will you please explain.
 
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...
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...

Similar threads

Back
Top