In retrospect the era from 1915 to 2003 was a retrograde era in cosmology because its basic theory was incorrect. Not only that but it is irretrievably incorrect and unworkable, as argued in paper 139. Observational astronomy on the other hand has developed strongly and continues to provide a wealth of data. The basic problem is that the twentieth century cosmology was based from its very beginnings on a flawed knowledge of geometry. Its geometry is Riemann geometry, devised in the early nineteenth century and developed by Christoffel and others. Up to about the early nineteen twenties, the existence of torsion was not known, and the commutator method was not known. The commutator method shows that any symmetric connection is zero. So the whole of Einsteinian cosmology collapses because of its use of a symmetric connection. The latter was just guesswork introduced by mathematicians of around the turn of the twentieth century. Hardly any textbook of general relativity mentions torsion, whereas the latter is just as fundamental as the curvature. Torsion and curvature must always be non zero and the connection must always be antisymmetric in its lower two indices. Therefore all the lurid propaganda about black holes, big bang and dark matter is complete nonsense, it is an industry rather than physics. Intolerant editors who hardly ever read submissions automatically adhere to the hopelessly flawed cosmology. Prestigious chairs are made out of flawed marble cut statements, and the whole lot is hopelessly muddied by string theory. It is now known clearly that four dimensions as used in ECE theory are sufficient for a unified field theory. Some very strange pseudo theorems such as the Hawking Penrose singularity theorems came to dominate cosmology, but the data build up an overwhelming case against them. With the retirement of Stephen Hawking (and I wish him all the best), it is time to move on and build a simpler, error free, cosmology. The basics of this are already available in papers 122 onwards. I would say that string theory is mathematics, not physics at all, string theory is not applied anywhere except in string theory. It is not used in the rest of physics, not used in chemistry, and not used in engineering and medicine. Any good physics works itself through into other subjects, and string theory has failed to do this in half a century.

## Looking Back at Twentieth Century Cosmology

Advertisements