SoylentNews is people
SoylentNews
from the did-it-never-happen,-or-was-it-unhappened? dept.
In the real world, your past uniquely determines your future. If a physicist knows how the universe starts out, she can calculate its future for all time and all space.
But a UC Berkeley mathematician has found some types of black holes in which this law breaks down. If someone were to venture into one of these relatively benign black holes, they could survive, but their past would be obliterated and they could have an infinite number of possible futures.
Such claims have been made in the past, and physicists have invoked "strong cosmic censorship" to explain it away. That is, something catastrophic -- typically a horrible death -- would prevent observers from actually entering a region of spacetime where their future was not uniquely determined. This principle, first proposed 40 years ago by physicist Roger Penrose, keeps sacrosanct an idea -- determinism -- key to any physical theory. That is, given the past and present, the physical laws of the universe do not allow more than one possible future.
But, says UC Berkeley postdoctoral fellow Peter Hintz, mathematical calculations show that for some specific types of black holes in a universe like ours, which is expanding at an accelerating rate, it is possible to survive the passage from a deterministic world into a non-deterministic black hole.
What life would be like in a space where the future was unpredictable is unclear. But the finding does not mean that Einstein's equations of general relativity, which so far perfectly describe the evolution of the cosmos, are wrong, said Hintz, a Clay Research Fellow.
Vitor Cardoso, João L. Costa, Kyriakos Destounis, Peter Hintz, Aron Jansen. Quasinormal Modes and Strong Cosmic Censorship. Physical Review Letters, 2018; 120 (3) DOI: 10.1103/PhysRevLett.120.031103
Source: http://news.berkeley.edu/2018/02/20/some-black-holes-erase-your-past/
(Score: 2, Informative) by JustNiz on Tuesday February 27 2018, @05:37PM (7 children)
> If a physicist knows how the universe starts out, she can calculate its future for all time and all space.
This hypothesis is has already been proved wrong.
> it is possible to survive the passage from a deterministic world into a non-deterministic black hole.
...presuming you can somehow survive the event horizon where the massive gravity difference just between various parts of your body would cause you to be stretched into a very long one atom-wide string.
> What life would be like in a space where the future was unpredictable is unclear.
Just look around you...
(Score: 3, Interesting) by wonkey_monkey on Tuesday February 27 2018, @06:45PM (1 child)
No it hasn't.
systemd is Roko's Basilisk
(Score: 3, Insightful) by aristarchus on Tuesday February 27 2018, @08:50PM
LaPlace is dead. This is what happens when you have scientists practicing metaphysics without a license.
(Score: 3, Insightful) by HiThere on Tuesday February 27 2018, @06:58PM (3 children)
There are disagreements between quantum physicists and relativity physicists about the nature of the boundary of the black hole. Relativity physicists say that there is no special place where you can observe the boundary. Some quantum physicists disagree. Nobody says you can survive falling into a small black hole, but one large enough should have a gradual boundary, such that the tide wouldn't tear you apart.
Then we get to the question of what the inside is like.... I'm not absolutely certain what the current belief is, but it has usually been believed that you have no way of escaping being compressed to infinite density, at which point the equations break down. IF there's no friction on the inside, which implies that all contained matter has either escaped earlier or condensed down to the core, then there are supposed to be paths through it which lead outside...possibly to the past, or another timeline, or some such. But this state of affairs is not generally believed to obtain.
Also, when observed from the outside it will appear to take an infinite amount of time to fall into the black hole. Most paths into it require either friction or achieving a velocity approaching that of light as a limit.
So the question really is what are the internal conditions like? And the best guess is that the spiraling accretion disk continues to spiral slowly inwards, and that you would be compelled to join that accretion disk. But this could be wrong, and there's no way to observe it so we'd know.
OTOH, if the "firewall" quantum physicists are correct, all the information contained within your capsule (including you) will be incinerated as you pass the boundary, and the information will be re-radiated as Hawking radiation. This will be spread over time (as measured from outside), as at that point you will be almost in orbit at nearly the speed of light.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 3, Insightful) by Immerman on Tuesday February 27 2018, @08:25PM (2 children)
>it will appear to take an infinite amount of time to fall into the black hole
For a generous enough definition of "infinite" and "appear" I suppose. Time would be passing only a bit slower than normal for the thing making the journey, meanwhile it will appear to accelerate rapidly toward the event horizon until it gets quite close, at which point it will seem to slow down and red-fade out to invisibility as the photons leaving it take an ever-increasing amount of time to travel the first small distance away from the horizon. Of course, there are a finite number of photons leaving it, so at some non-inifinte time the last one will have escaped, redshifted into the extreme infrared.
Of course it's likely that at some point long before that ideal "fade out", that the fluctuations in the event horizon will have released or absorbed the last bunch of photons all at once - after all black holes are constantly evaporating through Hawking radiation, and sometimes growing through absorbing more matter, and the event horizon itself will be constantly fluctuating as it's perturbed by other gravitational fields. Not much maybe, but that final burst of photons is probably trapped within a tiny fraction of a millimeter of the event horizon, so it wouldn't take much to tip them one way or the other.
Inside, last I heard, it's believed that their are no forces in existence that can resist the compression of gravity - that's why the thing collapsed in the first place. There's also no possibility of back-action - light itself can't move outward, and neither can any forces, so there's nothing to slow you down except your own angular momentum, which should, I would think radiate away from you (inward) as gravity waves. Or I suppose, collisions with things on their own degenerating orbit. And by "things" I mean "isolated atoms", or less, since even inter-atomic forces can't propagate outwards to hold larger structures together. The increasing non-locality of subatomic particles might allow them to behave differently, I really have no idea.
There's also no reason to assume you'd orbit anywhere near the speed of light. Light itself could theoretically hold an orbit just outside the event horizon, but nothing else has that kind of angular momentum, any massive particle would fall inwards on an elliptical path until it hit the event horizon, still going far slower than light speed.
(Score: 3, Insightful) by HiThere on Tuesday February 27 2018, @11:52PM (1 child)
Sorry, a bit of confusion. To the external observer it will appear to require an infinite amount of time. To the one falling time will appear to be passing as normal, in fact, things will be happening uncomfortably quickly. Also, to the external observer the frequency of the light emitted by the falling item will appear increasingly red shifted. This, in fact, is why it will appear to take an infinite amount of time, as each successive photon emitted will follow a path that takes it longer and longer to reach the external observer, stretching the wavelength as it traverses the path (losing energy to the gravitational field). Eventually, no matter how sensitive your detector, you won't be able to detect the falling item any longer, but there will be no indication that the fall has completed, and if you build an even more sensitive detector, you will still be able to detect it's increasingly red-shifted signal.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by requerdanos on Wednesday February 28 2018, @03:06AM
Now that's +1 material right there.
In reading TFS, and learning that instead facing certain "horrible death," one may now be assured that "for some specific types of black holes in a universe like ours... it is possible to survive the passage", I couldn't help but thinking something along the lines of "After you, kind sir." I was, to be honest, perhaps not so reassured as I should have been, and did suspect that things might go, as you say, "uncomfortably quickly" even absent the horrible certain death science would previously have predicted, and absent any particular sensation as the Schwarzschild radius is irrevocably crossed.
(Score: 2) by FakeBeldin on Wednesday February 28 2018, @10:36AM
First of all, it's not the event horizon that causes spaghettification [wikipedia.org], it's the insane gravity of the black hole. So it's not about surviving the event horizon, it's about surviving the insane curvature of space-time.
Secondly, Stephen Hawking describes in "A Brief History of Time" that certain black holes may be so massive, that their event horizon is very far out. For such black holes, you're not spaghettified at the event horizon. It's the point of no return, but that does not imply the point of spaghettification. In other black holes (smaller ones, e.g. ~10 solar masses), you'll be spaghettified before reaching the event horizon.
Cf. https://en.wikipedia.org/wiki/Spaghettification#Inside_or_outside_the_event_horizon [wikipedia.org].