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Math Shows Some Black Holes Erase Your Past and Give You Unlimited Futures (vice.com)
dmoberhaus writes: An international team of mathematicians has found that there are theoretical black holes that would allow an observer to survive passage through the event horizon. This would result in the breakdown of determinism, a fundamental feature of the universe that allows physics to have predictive power, and result in the destruction of the observer's past and present them with an infinite number of futures. The findings were detailed in a report published last week in Physical Review Letters.
Murph!!
This seems risky, even if it were possible to approach a black hole. In this case, I'll choose to not believe what my teacher tells me.
"Math isn't going to bring you back from the dead"
https://www.youtube.com/watch?...
Summary implies conflation of mathematical artefacts with physical reality. Real paper is probably quite dry and abstract.
They mean pork belly futures.
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
This looks like a division by zero.. but instead of understanding the logical error that put them in that impossible situation and fixing it, they just keep on doing more math over it....
When mass hits the speed of light, it does not travel back in time... It just louses all mass properties and turns into light.
1/(x*x) will never be negative with a real input!!!
Math does not apply to reality. It always only applies to an abstraction of reality and that loses accuracy, sometimes catastrophically as almost certainly happened in this case.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
People tend to believe that physics is applied math. It's not. The universe doesn't care about your math. General Relativity is a set of mathematical equations that were picked because they could model the observed experimental data. Yes, it proved to be a very accurate theory by predicting future experimental results decades after it was published. That doesn't mean that every single prediction will be true. So until an experiment can confirm these results, nothing has been "shown", as the headline implies. This doesn't mean these findings aren't relevant. On the contrary, finding these edge cases is what allows theories to be tested and be eventually replaced by a better model.
Only difference between black holes and neutron stars is black holes overcome pauli and everything collapses into a shared state. Big whoop. Assertions of "infinite density" are nonsense. There is no evidence single massive shared states have exactly zero extent or that length is not quantized and energy sure as heck is not infinite so jumping to "infinite density" conclusions is premature at best. Neither is there anything special about escape velocities approaching C. Of course there are effectively incalculable (yet not unlimited) futures embedded in the ginormous quantum state making up the black hole.
Infinite density is a scam.
Determinism is a scam.
(Ir)reversibility as constructed is essentially a tautology.
I'm not in the field either, but I hope someone can explain this a little better since the actual paper is behind a paywall and the oversimplified and popularized Motherboard article doesn't make any sense.
Motherboard says that the laws of the universe, outside of black holes, are supposedly deterministic. That's news to me, I thought quantum mechanics dealt with probabilities and there was no way to predict what part a particle will take. The universe plays dice all the time, it only appears to be deterministic on a large scale when the probabilities of the individual particles average out to a largely predictable macroscopic result.
Then, what does it mean when they say your past is destroyed? Let me get this straight, you fall into one of these special black holes, you survive (which, I assume, includes your memories), yet your past is "destroyed"? I imagine they mean that the laws transfer to a different coordinate system where your past is no longer at negative time coordinates but simply nowhere at all. Which isn't really that unusual. Just use a different coordinate system (one tied to your body) and the past will be there again, still inaccessible at the usual negative coordinates (but formulas for describing your current environment will be very complicated). Pretty sure that's what they meant, right?
OK, what about the unlimited futures? Again, I though quantum mechanics already gave us those. I guess it means that the future will be a lot more undeterministic than usual?
Finally, the big discovery seems to be that you won't be destroyed by all the energy of the universe falling through the event horizon at the same time as you, thanks to the expansion of the universe. But what about spaghettification? Won't you still be killed by the enormous differential gravitation even if you survive the radiation at the horizon? How does the charge of the black hole prevent that from happening?
Thanks in advance to anyone who can clear this up a bit more.
Those experiencing it claim the past really did change and it's not their faulty memory. It's name comes from them remembering Nelson Mandela dying in prison in the 80's.
All those parking tickets: gone!
Table-ized A.I.
... determinism, a fundamental feature of the universe ...
While we may wish for determinism, it has been shown long before that it does not exist.Since it was shown that we can not accurately know both the position of a particle and its speed, it has been proven that predicting the future is impossible because it is impossible to know the present, let alone calculate the future by using the present as a starting condition. So determinism is absolutely not a feature of the universe.
Nae king! Nae laird! Nae yurrupiean pressedent! We willna be fooled again!
Not quite, e.g.: https://en.wikipedia.org/wiki/Superdeterminism
In quantum physics the approach of following the mathematical theory to its logical conclusion, how weird that may sound, has been quite successful. In any case such speculations make sense to test a theory and see where it leads to. Maybe it'll even lead to possible experimental tests of the theory (although I don't think humanity will have access to a black hole (specifically one that is big enough) to play around with.
The Einstein-Podolsky-Rosen-Paradoxon is a good example of following a theory (here quantum mechanics) to it's logical conclusion. Effectively the "paradoxon" exposes the nonlocality of quantum mechanics i.e. it implies "spooky actions at a distance", a picture that clashes with our classical world view. Based on this an experiment was thought up, a test of the "bell inequality". Basically any classical theory that preserves locality should always fulfil the bell inequality. OTOH quantum mechanics predicts a violation of the bell inequality in experiments specifically designed for that purpose. Such experiments then showed a violation of the inequality. This means, that a classical theory (which would include locality) can not explain those experimental results (which are predicted by quantum mechanics).
So the speculations of Einstein, Podolsky and Rosen about the strange consequences of quantum mechanic theory led to a fundamental insight about the nature of reality, namely that there are aspects of it that can not be explained by a "classical" theory that includes locality.
So if one wants to test a mathematical description of reality one has to follow the mathematics to its logical conclusions and if possible test if these apply to the real world. Even if such a test is not possible it is often helpful to see what the implications of a mathematical model are. Maybe it leads to a better understanding, uncovers contradictions or shows that a theory is incomplete, but in some cases it can also lead to a deeper understanding of reality.
"By the way if anyone here is in advertising or marketing... kill yourself." -- Bill Hicks
I hereby demonstrate my complete lack of understanding slashdot readers by linking to the full article on arxiv It's kind of an interesting mathematical exercise in the physics of charged black holes under various conditions but obviously does not reflect reality. For example, you would need a large positive cosmological constant, and an extreme ratio of charge to mass for this to be relevant. Further the clickbait headline implies some kind of retroactive erasure of the onserver when in reality it just means you can't reconstruct the past from future observations due to a breakdown in how the math works. This may not even be true at all because we know that general relativity does not fully describe spacetime at the extremes found at the surface horizons of black holes anyway.
> Finally, the big discovery seems to be that you won't be destroyed by all the energy of the universe
> falling through the event horizon at the same time as you, thanks to the expansion of the universe.
The catch here is that, "all the energy in the universe," may not be hitting you as you fall through the event horizon, but a lot will, more than likely enough to give you a Bad Day. You're only down from "infinity" to "the horizon observable over the black hole's future," still a pretty big number.
> But what about spaghettification?
Others have answered this, that the gravity gradients are soft enough around a big enough black hole.
There is another fun fact here... For spinning black holes, which I believe means most of them, or at least the big ones we could think of entering in the non-spaghetti state, there are actually two event horizons, and it might be possible to leave from the zone in between them. Gregory Benford, physicist and science fiction author, set several books in that region.
The living have better things to do than to continue hating the dead.
Just to nitpick: thr fact that we can not measure the present does not mean that the future is not deterministic.
The particle you measure will go where it goes, unless you measure it. Then it is going where your measurement is deflecting it to.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
https://arxiv.org/abs/1711.105...
OK, what about the unlimited futures? Again, I though quantum mechanics already gave us those. I guess it means that the future will be a lot more undeterministic than usual?
It means that there is still a possibility that I get to have a threesome with Alizee and Selena Gomez. Now if I could only find a black hole...
I'm not a complete idiot... Some parts are missing.