4:50 AM
4

For generic black holes one demonstrates that the event horizon is just a coordinate singularity by changing coordinates to a system where the metric is well defined. For example we have Kruskal-type coordinates $U_\pm\sim e^{\pm \kappa u_\pm}$ with $\kappa$ the surface gravity. In terms of these...

11 hours later…
4:16 PM
2

I read in Ian Stewart's 17 Equations that Changed the World book that Navier-Stokes equation (I know it's not exactly a scientific book, but still, I'd like clarification on what is wrong if it's the case): \$\rho \left( \dfrac{\partial v}{\partial t} + v \cdot \nabla v\right) = -\nabla p + \nabla...