Prof. Hawking's final science paper released

[Still Waters]

Stephen Hawking’s final scientific paper has been released by physicists who worked with the late cosmologist on his career-long effort to understand what happens to information when objects fall into black holes.

The work, which tackles what theoretical physicists call “the information paradox”, was completed in the days before Hawking’s death in March. It has now been written up by his colleagues at Cambridge and Harvard universities and posted online.

Malcolm Perry, a professor of theoretical physics at Cambridge and a co-author on the paper, Black Hole Entropy and Soft Hair, said the information paradox was “at the centre of Hawking’s life” for more than 40 years.

https://www.theguardian.com/science/2018/oct/10/stephen-hawkings-final-scientific-paper-released

[acute]

I watched a documentary about Stephen Hawking's black hole theories shortly after he died, and it was fascinating.

[danydandan]

Quote

 A set of infinitesimal VirasoroL⊗VirasoroR diffeomorphisms are presented which act non-trivially on the horizon of a generic Kerr black hole with spin J. The covariant phase space formalism provides a formula for the Virasoro charges as surface integrals on the horizon. Integrability and associativity of the charge algebra are shown to require the inclusion of `Wald-Zoupas' counterterms. A counterterm satisfying the known consistency requirement is constructed and yields central charges cL=cR=12J. Assuming the existence of a quantum Hilbert space on which these charges generate the symmetries, as well as the applicability of the Cardy formula, the central charges reproduce the macroscopic area-entropy law for generic Kerr black holes.

This is the abstract for the last paper Dr Hawkin had a hand in writing. It was published on the 9th of October.

https://arxiv.org/abs/1810.01847v2

https://www.bbc.com/news/science-environment-45826748

It's basically about black hole information theory, which was the primary subject that Dr Hawkin was researching. It tackles information paradox specifically, and the paper attempts to show that information 'thrown' into a black may be preserved. So if you add information or anything to a black hole it's temperature should increase, hence the entropy increases as the temperature does also. Effectively the physicists who wrote the paper are saying that 'soft hair' can account for the increase in entropy. This sheen of photons around the black hole potentially can record the entropy of the black hole.

So a little joke, good information is thrown into a black hole, and Facebook converts it to memes and rubbish, thus increasing the Universes entropy. However we can't confirm if this conversion occurs in the black hole or when the escaping information crosses the event horizon.

All jokes aside, it's quite interesting. Also if this should be in the space section, you mods are free to change what section this is in.

Enjoy reading the paper, it's the last paper worked on by one of the greatest minds us mortals have ever seen.

Edited October 11, 2018 by danydandan