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Are black holes the ruthless killers we’ve made them out to be? Samir Mathur says no. According to the professor of physics at Ohio State University, the recently-proposed idea that black holes have “firewalls” that destroy all they touch has a loophole.
In a paper posted online to the arXiv preprint server, Mathur takes issue with the firewall theory, and proves mathematically that black holes are not necessarily arbiters of doom. In fact, he says the world could be captured by a black hole, and we wouldn’t even notice.
More than a decade ago, Mathur used the principles of string theory to show that black holes are actually tangled-up balls of cosmic strings. His “fuzzball theory” helped resolve certain contradictions in how physicists think of black holes.
But when a group of researchers recently tried to build on Mathur’s theory, they concluded that the surface of the fuzzball was actually a firewall.
According to the firewall theory, the surface of the fuzzball is deadly. In fact, the idea is called the firewall theory because it suggests that a very literal fiery death awaits anything that touches it.
Mathur and his team have been expanding on their fuzzball theory, too, and they’ve come to a completely different conclusion. They see black holes not as killers, but rather as benign copy machines of a sort.
https://news.osu.edu/news/2015/06/16/fuzzyhologram/
Original Submission
(Score: 2, Insightful) by Anonymous Coward on Thursday June 18 2015, @02:39PM
Translation: "I have no clue about physics, but still I think I know better than Einstein who actually studied it."
(Score: 2) by c0lo on Thursday June 18 2015, @06:39PM
Then how come two different singularities can have a different attributes, like mass, size, momentum etc?
To put it another way: how come the gravity of a black hole can escape the black hole?
* (for some values of everybody)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 3, Informative) by maxwell demon on Thursday June 18 2015, @07:23PM
Sort of: For the non-rotating black hole, the singularity is actually in the future (the "radial" coordinate is actually a time coordinate inside the black hole). And for rotating black holes, the singularity isn't a point, but a ring. But if you take quantum mechanics iunto account, probably a singularity doesn't form anyway.
Anyway, the defining characteristic of a black hole is the horizon, not the singularity.
The mass is not a property of the singularity, but of the vacuum around it (yes, vacuum can have mass if it is curved).
It can't. All the gravity of the black hole was generated by the matter the black hole was formed from or which was falling into it afterwards.
In particular, the gravitational waves of two merging black holes are generated by the warping spacetime outside of the black hole. Any gravitational waves which are generated inside will indeed not get out.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Thursday June 18 2015, @07:35PM
Looks, sounds, and walks like theoretical speculation no better nor worse than philosophy. Why is physics considered harder than philosophy when they do the same theoretical musings to make these bad fit interpretations and all their special use cases?
And a more honest question about this:
Is this a technical semantic point or is it a factual one? If it is a factual one, then there can be a singularity without a horizon and an associated vacuum with mass. But is it really a vacuum with mass if it requires a singularity? That would be like saying that a vacuum can taste like chocolate just so long as chocolate to be present.
(Score: 2) by maxwell demon on Thursday June 18 2015, @09:56PM
General relativity indeed allows for "naked singularities", that is, singularities which are not hidden behind a horizon. Whether they also exist in nature is another question; up to now, we haven't found one.
A vacuum with mass does not need a singularity. Indeed, you have it with every gravitating body; it's just that for the usual bodies the extra mass obtained that way is so small there that it usually doesn't matter compared with the mass of the object itself.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 1, Flamebait) by aristarchus on Thursday June 18 2015, @11:11PM
Why is physics considered harder than philosophy when they do the same theoretical musings to make these bad fit interpretations and all their special use cases?
Because physicists use math, lots of math, and that generates the fallacy of misplaced concreteness, and theoretical fuzzy blackholes, evidently.
(Score: 2) by c0lo on Thursday June 18 2015, @08:16PM
So it's space that causes mass, not mass deforming space, mmm?
Then what about the other properties: momentum, charge, etc.? Since everything is blocked by the horizon, you say except the size of the horizon there should be no difference between the Sagittarius black hole and the (hypothetical) black hole created by squeezing a proton beyond its schwarzschild radius (forget the evaporation rate, consider only the charge, spin)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2, Interesting) by Absolutely.Geek on Thursday June 18 2015, @09:03PM
a black hole is supposed to have a singularity at it centre, right? Like a point of infinite gravity, isn't it? Then how come two different singularities can have a different attributes, like mass, size, momentum etc?
In the most basic terms density and mass are not the same thing.
If the sun were to turn into a black hole; we here on earth would notice no difference (except for the strange lack of light); an event horizon would exist because the density of the singularity, that harizon would be well inside the current radius of the sun. Black holes can have differnet masses and therefore momentum because the matter that went into making them up had a specific amount of mass. Because the masses of black holes are different that means that the raduis of the event horizon will be different for every black hole.
everybody* looks for gravitational waves, 'cause, you know, nothing can go faster then light - so there should be waves. Suppose you throw another small black-hole into a huge one: that should show a notable perturbation in the gravity of the receiver, except this info can't get out.
Ok lets suppose that you have a "small" black hole; any small object that is a stable black hole already has many solar masses of stuff trapped in there; and you throw it at a "big" black hole. It is much more interesting if the black holes are similar masses for the same reason that hitting a marble with a marble produces more intersting results the hitting a car with a marble.
But ok we have two black holes traveling towards each other; first thing well before the event horizons get close they are interacting with their regular gravitational fields. Thus the path of both holes is being modified well before they are close; if you get lucky and they are perfectly aligned the small hole will merge with the large hole and there will be a massive release of energy in the form of gravity waves rippling out from the point of the merger; the resultant now more massive black hole will travel in the direction of the larger black holes original path.
The more likely outcome (assuming they come "close") is that they are not traveling exactly opposite directions and they endup orbiting each other for a time; in this situation the smaller black hole eventually spirals into the the entire time energy is being released as gravity waves because space-time is being dragged around by these huge objects.
The third option is that the black holes are "far" apart; the two black holes trasnfer some momentum (gravity boost) and the smaller black hole possibly achieves escape velocity and leaves the galaxy, or it trasnfers momentum the other way the big hole spees up slightly and the smaller hole slows down a lot and falls towards the centre of the galaxy.
Don't trust the police or the government - Shihad: My mind's sedate.
(Score: 1) by budgenator on Thursday June 18 2015, @09:44PM
I always assumed that anything inside the event horizon, was undefined from the outside, well anything other than mass, charge and angular momentum. What interesting to me is when two blackholes approach each other and the event horizons distort from the other's gravity, possibly enough for a larger singularity to cause a small singularity to become naked.
(Score: 2) by c0lo on Thursday June 18 2015, @10:50PM
Even if it doesn't become naked, it's still weird.
You'd have two event horizons (defining singularities at their centers) which suddenly become one and deny info about what happens inside.
Including the fact that the geometry of the ensemble during the transition is non-spherical?
In their way to becoming one big blackhole, the variation of mass density inside the envelope of the resulting event horizon would surely produce gravitational waves, but they can't escape. So, what happens with the shape of the event horizon as seen from outside - does it stays the same as at the moment of collision? Or can the observer feel the redistribution of mass by observing the shape of the horizon, thus have information "escaping" it?
Suppose the two blackholes are rotating; the angular momentum of the resulting blackhole - after reaching equilibrium - changes (it will change even if not initially rotating, if the collision is not dead-centre). As such, frame dragging [wikipedia.org] changes. But what happens during the time of the collision with frame-dragging?
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford