The continuity equation says that if there's a constant amount of water going through the river, ... This would hardly be physics if the same equation didn’t apply to incredibly different systems.

Continuity Equation When a fluid is in motion, it must move in such a way that mass is conserved. To see how mass conservation places restrictions on the velocity field, consider the steady flow of ...

F or the first time, a mathematical framework proves that Einstein’s theory of general relativity, which explains the ...