All Questions
5
questions
2
votes
1
answer
201
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Is the celestial sphere we actually see the Riemann Sphere?
I've been watching a few lectures by R. Penrose where he seems to say that what we see around us is the Riemann sphere. He usually gives the example of an observer floating in deep space or if the ...
- 31
0
votes
0
answers
141
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Question about the geometric structure of Newtonian mechanics
My point here is about the mathematical structure of Classical pre-relativistic physics and general relativity (GR).
It became more clearly, after GR, about the fact that pseudo-riemannian are a nice ...
- 3,085
5
votes
2
answers
724
views
Why is general relativity a geometric theory?
Please define what is a geometric theory. Also give examples of theories which are not geometric.
- 837
9
votes
1
answer
694
views
Can masses move in 2+1 gravity?
I would like to understand basic concepts of the general relativity in 2+1 spacetime. As far as I know, GR predicts that such a spacetime is flat everywhere except for the point masses which create ...
- 2,173
1
vote
2
answers
1k
views
What is a geometrical object?
From the Wikipedia link for Geometry:
Geometry (Ancient Greek: γεωμετρία; geo- "earth", -metron "measurement") is a branch of mathematics concerned with questions of shape, size, relative position ...
- 5,318