Einstein brilliantly wrote about the influence of gravitation on time in his article on General Relativity. Then came Emmy Noether’s theorem: Energy conservation demands a constancy of the constants of physics, like the speed of light: they must be invariant to time translations. She wrote to Einstein that his GR...

## The day Relativity changed

loopdoctorNovember 30November 300Level I Student, Level II Advanced, Level III Doctor

Einstein started publishing on his General Relativity in January-February 1916. On these articles Karl Schwarzschild based his exact solutions. On 11 May that year, however, Einstein published is official GR – with a little but important change: no more two equal reference frames. Too late for Karl. Other...

## Properties of a torus-shaped Black hole

loopdoctorOctober 31October 310Level II Advanced

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 Einstein...

## Einstein’s neglected demands of GR solutions

loopdoctorOctober 26October 260Level III Doctor

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: abiding...

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 evidence. A...

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...

## No ‘Event Horizon’ in New Time-like Solution

loopdoctorFebruary 15March 160Level III Doctor

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...

## Shapiro annihilates Eddington’s “drop the suffix”

loopdoctorFebruary 11February 120Level II Advanced

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...