Recent content by Blub

That makes sense. I think I was also comparing tangent vectors living in different tangent spaces in my mind and got confused about the notion of velocity on a manifold. Thank you for your help.

I am studying GR and I have these two following unresolved questions up until now: The first one concerns the Levi-Civita connection. There are two conditions which determine the affine connections. The first one is that the connection is torsion-free (which is true for space-time and comes...

Thank you for your answers. Non-scientific interpretations of physical phenomena are so widespread and often non-consistent with the things I learned, that I keep getting unsure about my understanding, especially about their supposed consequences for the every-day world.

I keep reading things like the following (for me not correct) on different websites like researchgate (coming from supposedly phd.), so I wanted to make sure there is no flaw in my thinking. One example of a comment I've read was: "TIME is an ILLUSION according to EINSTEIN - (the space-time...

I have questions concerning group theory, esprecially Rotation groups. The first is: Are rotations groups f.ex. SO(2) defined for rotations in the actual physical 2 dimensional plane or are general rotations in any 2 dimensional space included? Someone wrote that "the action of an element of...