Why can't our universe be spherical?
4276
Did the Big Bang happen at a point?
20511
Is it possible to experimentally show that observable universe is much larger than ~93B ly?
76894
Why is spacetime not Riemannian?
59422
Gravity in other than 3 spatial dimensions and stable orbits
95681
If the universe is 3D, how is space-time like a "fabric"?
114290
Is it possible to have a singularity with zero mass?
6486
Why isn't dark matter just ordinary matter?
115517
How could we know that the relativistic curvature of universe is intrinsic?
64286
How can gravitions exist without violating GR?
149430
Why does the universe exhibit three large-scale spatial dimensions?
66524
The Impossibility ( or Possibility) of Solving $N$-Body Problem
129542
Do perfect spheres exist in nature?
76637
Why aren't particles constantly "measured" by the whole universe?
9388
Can matter be described as the result of the curvature of space, instead of vice versa?
92674
Could spontaneous symmetry breaking happen again in our universe?
51042
How is it possible to come to a conclusion that Universe is a result of the Big Bang while we aren't able to observe the entire Universe?
5930
Why is the observable universe so big?