Jump to content

The End of the Firewall argument?


beecee
 Share

Recommended Posts

https://phys.org/news/2018-07-black-holes-ever-growing-balls.html

Black holes really just ever-growing balls of string, researchers say

July 26, 2018 by Misti Crane, The Ohio State University

Black holes aren't surrounded by a burning ring of fire after all, suggests new research.

 

Some physicists have believed in a "firewall" around the perimeter of a black hole that would incinerate anything sucked into its powerful gravitational pull.

But a team from The Ohio State University has calculated an explanation of what would happen if an electron fell into a typical black hole, with a mass as big as the sun.

"The probability of the electron hitting a photon from the radiation and burning up is negligible, dropping even further if one considers larger black holes known to exist in space," said Samir Mathur, a professor of physics at Ohio State. The study appears in the Journal of High Energy Physics.

The new study builds on previous work from 2004 led by Mathur that theorized that black holes are basically like giant, messy balls of yarn—fuzzballs" that gather more and more heft as new objects are sucked in. That theory, Mathur said, resolved the famous black hole "information paradox" outlined by Steven Hawking in 1975. Hawking's research had concluded that particles entering a black hole can never leave. But that ran counter to the laws of quantum mechanics, creating the paradox.

The firewall argument emerged in 2012, when four physicists from the University of California, Santa Barbara argued that any object like a fuzzball would have to be surrounded by a ring of fire that will burn any object before it could reach the fuzzball's surface.



Read more at: https://phys.org/news/2018-07-black-holes-ever-growing-balls.html#jCp

::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

 

http://www.physics.ohio-state.edu/~mathur/firewallstory2.pdf

The end of the firewall story?

In 2012 a group of physicists (Almheiri, Marolf, Polchinski and Sully) from the University of California, Santa Barbara, made a startling claim: in any theory where black holes do not lose information, a person falling towards the hole will get ‘burnt’ by a ‘firewall’ of radiation as he approaches the horizon of the black hole [1]. This claim flew in the face of earlier theories where information was not lost and where an infalling observer could maintain a sense of ‘falling freely through empty space’ as he reached the horizon. In 2014, Mathur and Turton pointed out the flaw in the firewall argument: an assumption in the argument implied that information travels faster than light to escape the hole [2]. With the offending assumption removed, an explicit model of the black hole could be made which bypassed the firewall argument. There remained, however, a last piece of the firewall story, which was closed in a paper by Guo, Hampton and Mathur, due to appear shortly in the Journal of High Energy Physics. In considering the behavior of black holes, it is normally assumed that the holes are large; i.e., their mass is much larger than Planck mass, the microscopic mass scale where quantum gravity effects begin to take over. Marolf (one of the authors of the firewall argument) had agreed that Mathur and Turton’s suggested process provided a way around the firewall claim for sufficiently large holes. But he questioned if the astrophysical holes we observe around us are large enough for the scenario to work. This may sound odd, since a solar mass hole is about 1038 times heavier than Planck mass. But the arguments of Mathur and Turton assumed that the firewall would burn infalling objects by gravitational interactions, and for holes that are not too large, electromagnetic interactions might be more important than gravitational ones. The electrostatic repulsion between two electrons is about 1042 times stronger than the gravitational attraction between the electrons. For sufficiently large holes gravitational effects would have to dominate in any firewall, but perhaps astrophysical holes were small enough that electromagnetic effects would create the conjectured firewall. In that case there might be a window for the firewall argument; i.e., a range where the black hole is large enough to be interesting but small enough for the Mathur-Turton scenario to not apply. In their new paper, Guo, Hampton and Mathur explored the possibility of firewalls for astrophysical holes, now including interactions from all four fundamental forces: gravitational, electromagnetic, strong and weak. They found that the earlier Mathur-Turton argument against firewalls continued to hold, unless the hole was smaller than onehundredth the size of an atom. This ruled out firewalls for holes of astrophysical interest, closing the last loophole in the argument of Mathur and Turton against firewalls

 

more......

Edited by beecee
Link to comment
Share on other sites

38 minutes ago, MathGeek said:

Great.  Duelling theories.  

Is there an experiment available to pick a winner?

You know, how science should work.

Yes. Its easy. We just fly to a black hole and drop in a scientist and observe what happens. :)

Link to comment
Share on other sites

8 hours ago, MathGeek said:

Great.  Duelling theories.  

Is there an experiment available to pick a winner?

You know, how science should work.

I can throw a few more theories into the mix, if you like ;) We’ve quite a selection to choose from!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.