Einstein used a complicated set of tensors in his General Relativity. However in his writing in 1916 he used a Laplace operator, which can help us to determine the gravitational potential inside a sphere without having to go into his field equations. Many surprising results: The behaviour of clocks is in line with all...

Einstein’s publication in the ‘Annalen der Physik’ urged many scientists to work. Did you know that there are five different Schwarzschild Solutions? How do you know which one is right? This article presents you three ways to check the outcome: The General Relativity Principles, the GR field equations and the Laplace...

Einstein’s General Relativity contains the Laplace operator of a sphere of incompressible liquid. It links the time-like solution (how fast does the clock tick) directly with the gravitational potential: no need for using tensor operations. He never applied it to the potential inside a sphere. This article is doing...