Cosmology: Einstein general relativity supported again (Introduction)

by David Turell , Thursday, October 01, 2020, 22:42 (1303 days ago) @ David Turell

Using black hole measurements:

https://phys.org/news/2020-10-einstein-description-gravity-harder.html

"Einstein's theory of general relativity—the idea that gravity is matter warping spacetime—has withstood over 100 years of scrutiny and testing, including the newest test from the Event Horizon Telescope collaboration, published today in the latest issue of Physical Review Letters.

"According to the findings, Einstein's theory just got 500 times harder to beat.

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"We expect a complete theory of gravity to be different from general relativity, but there are many ways one can modify it. We found that whatever the correct theory is, it can't be significantly different from general relativity when it comes to black holes. We really squeezed down the space of possible modifications," said UArizona astrophysics professor Dimitrios Psaltis

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"To perform the test, the team used the first image ever taken of the supermassive black hole at the center of nearby galaxy M87 obtained with the EHT last year. The first results had shown that the size of the black-hole shadow was consistent with the size predicted by general relativity.

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"'Using the gauge we developed, we showed that the measured size of the black hole shadow in M87 tightens the wiggle room for modifications to Einstein's theory of general relativity by almost a factor of 500, compared to previous tests in the solar system," said UArizona astrophysics professor Feryal Özel, a senior member of the EHT collaboration. "Many ways to modify general relativity fail at this new and tighter black hole shadow test.'"

Comment: It seems that quantum considerations will have to be added to any new theory while the general relativity will hold its position.