Einstein wrote about the influence of gravitation on time in his theory of General Relativity. Then came Emmy Noether’s theorem: Energy conservation demands invariance of the constants of nature, like the speed of light. She wrote to Einstein that his theory cannot guarantee energy conservation in strong...

Einstein published his theory of General Relativity (GR) in stages. Based on these publications, Karl Schwarzschild found two exact solutions in January and February 1916. However, on May the 11th of that year, Einstein published his official GR – with important changes effecting both of Karl’s exact...

The ‘photo’ of the black hole in M87 is already iconic. The ‘Event Horizon telescope’ gave us a valuable look on the enormous object. But what do we see?ETH think it is the accretion disk (sending radiowaves) around the event horizon of a singularity. This conflicts with physics, Karl Schwarzschild and...

The Theory of General Relativity is very complicated mathematics. Einstein formulated a number of demands to ensure that solutions match measurement physics. Exact Schwarzschild solutions have later been changed by astronomers, unscientifically, to get rid of difficult issues.The relevance is great:...

  The ‘Event Horizon Telescope’ presented us with a stunning view of a black hole, far, far away in galaxy M87. A great and valuable result! Important to mention that the suggestion of Event Horizon positioned outside of a black hole is a myth, not supported by any theoretical or observational...

Black Hole Singularities and Wormholes: Albert Einstein would have warned against them and Karl Schwarzschild would have corrected these ideas, caused by errors. This article explains extensively the history behind these errors and also how they must be repaired. It turns out that a so called Event horizon belongs in...

Contrary to popular believe, there are many Schwarzschild Solutions. Karl himself found one to a mass-point and one to a sphere of in-compressible liquid early 1916. After Karl’s death Einstein made important changes in his  official publication: he abandoned his g = -1 requirement in a footnote. Nobody checked...

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 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...

Long after Einstein’s death, Shapiro sent a radar signal to Venus, in its position opposite of the sun, and half an hour later received it back. With this astonishing experiment he proved part of the delay (190 microsec) was caused by the gravitation of the sun.   Eddington, expert in Einstein’s theory of General...