Since sound travels as longitudinal waves, sound waves should only be able to propagate in a medium through compressions and rarefactions. However, water, as a liquid, is generally treated as an incompressible fluid. Since compression is essential to sound propogation, how do phenomena such as wh...

What I heard from books or other materials is that the heat is nothing but a sum of movements of molecules. So, as you all know, one common myth breaker was like "Unlike movies, you don't get frozen right away when you got thrown out to the space". But the thing which bugs me is that things in th...

The main question I would like to ask is whether quantities such as density are dependent on the frame of reference. I have searched several forums and the answer is somewhat controversial. Some answers use the concept of relativistic mass to justify that it is invariant. Some of the answers say ...

Carroll writes in his Spacetime and Geometry book on page 68 that "[...] in fact, however, we could just as well have begun with an intrinsic definition of one-forms and used that to define vectors as the dual space. Roughly speaking, the space of one-forms at $p$ is equivalent to the space o...