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Such pathways could connect one area of our universe to a different time and/or place within our universe, or to a different universe altogether.
Whether wormholes exist is up for debate. But in a paper published on Oct. 10 in Physical Review D, physicists describe a technique for detecting these bridges.
The method focuses on spotting a wormhole around Sagittarius A*, an object that's thought to be a supermassive black hole at the heart of the Milky Way galaxy. While there's no evidence of a wormhole there, it's a good place to look for one because wormholes are expected to require extreme gravitational conditions, such as those present at supermassive black holes.
In the new paper, scientists write that if a wormhole does exist at Sagittarius A*, nearby stars would be influenced by the gravity of stars at the other end of the passage. As a result, it would be possible to detect the presence of a wormhole by searching for small deviations in the expected orbit of stars near Sagittarius A*.
"If you have two stars, one on each side of the wormhole, the star on our side should feel the gravitational influence of the star that's on the other side. The gravitational flux will go through the wormhole," says Dejan Stojkovic, PhD, cosmologist and professor of physics in the University at Buffalo College of Arts and Sciences. "So if you map the expected orbit of a star around Sagittarius A*, you should see deviations from that orbit if there is a wormhole there with a star on the other side."
[...] While current surveillance techniques are not yet precise enough to reveal the presence of a wormhole, Stojkovic says that collecting data on S2 over a longer period of time or developing techniques to track its movement more precisely would make such a determination possible. These advancements aren't too far off, he says, and could happen within one or two decades.
Stojkovic cautions, however, that while the new method could be used to detect a wormhole if one is there, it will not strictly prove that a wormhole is present.
"When we reach the precision needed in our observations, we may be able to say that a wormhole is the most likely explanation if we detect perturbations in the orbit of S2," he says. "But we cannot say that, 'Yes, this is definitely a wormhole.' There could be some other explanation, something else on our side perturbing the motion of this star."
Though the paper focuses on traversable wormholes, the technique it outlines could indicate the presence of either a traversable or non-traversable wormhole, Stojkovic says. He explains that because gravity is the curvature of spacetime, the effects of gravity are felt on both sides of a wormhole, whether objects can pass through or not.
Dai's work was supported by the National Science Foundation of China, National Basic Research Program of China, and the Shanghai Academic/Technology Research Leader program, and Stojkovic's work by the U.S. National Science Foundation.
Journal Reference: De-Chang Dai, Dejan Stojkovic. Observing a wormhole. Physical Review D, 2019; 100 (8) DOI: 10.1103/PhysRevD.100.083513
(Score: 2) by Common Joe on Sunday October 27 2019, @01:17PM (22 children)
Ok, I'm not a physicist, so anyone who's better than me, please rip my idea to shreds but...
If stars at the other end of a black hole can influence a star's orbit at this end, that means that you can send gravitation waves out of a black hole. (At the speed of light?) If you can send gravitation waves out of a black hole, then a black hole can leak information. But... I thought black holes couldn't leak information?
Can anyone else shed a little light on this idea?
(Score: 5, Interesting) by Anonymous Coward on Sunday October 27 2019, @02:26PM (7 children)
A black hole and a traversable wormhole are different things.
Gravity is the bending of spacetime, ergo the differentiating factor is that gravity on one side will traverse because it is bending spacetime on both sides of the wormhole. It's not a "thing escaping", it's just spacetime being bent.
I agree it's an interesting hypothesis if correct, but you're wrong that nothing ever escapes a blackhole.
When most people think of a blackhole they have the mental image wrong.
They imagine a gap in space. A giant void sucking in everything and from which nothing escapes.
This is wrong. A black hole, even a static, non-charged, non-rotating blackhole is a complex dynamic object.
Throw rotation and/or charge into the mix and the the blackhole becomes quite a bit more dynamic.
Static black holes (the ones everyone talks about, but also the ones least likely to exist) contain an event horizon and a singularity.
The event horizon is what you are thinking of when you say that nothing can escape. The event horizon is the point where space is bent in on itself so extremely that there are no paths that point outward (unless you're moving at superluminal speeds).
Therefore it is true, inside the event horizon there is no escape path. No mass or energy that crosses the event horizon can ever get out.
There is a caveat though. That caveat is... "as long as the event horizon remains".
This is why hawking radiation kills black holes, it actually takes away from the event horizon shrinking it, and it doesn't particularly effect the mass at the center of the blackhole. There is one solution which proves if hawking is correct, that naked singularities would arise.
So the whole "point of no return, there is no escape thing", it's not the blackhole per se, it's the space time around it, the so called event horizon. Once that's taken care of escape is possible.
But how can the event horizon "go away" besides waiting for 10 pow 100 years for hawking radiation to do it's thing?
Rotating blackholes have another region called an ergosphere. Rapidly rotating blackholes do not have a singularity, they have a "ringularity".
The math shows that a spinning charged blackhole would automatically have an exit point in either a new universe or somewhere else in the current universe.
However that endpoint is still inside the event horizon of a black hole.
This changes the dynamics, because the faster a blackhole rotates, the smaller the event horizon and the larger it's ergosphere. It doesn't take much spin at all in fact for the ergosphere to be extremal to the event horizon. The ergosphere is named as such because it is possible to extract mass and energy (ergo means work) from the blackhole at this point. It is also possible although debatable for a blackhole to be spinning fast enough that it has no event horizon. This would leave the ringularity naked. There is a "cosmic censorship conjecture" which supposedly prevents this, but to be honest I cannot find any actual support for such a conjecture, that isn't just an appeal to authority.
For reasons explained below the CCC might not be necessary anyways if LQG turns out to be accurate.
Everything we know about blackholes is making this strange assumption by assuming that singularities and ringularities are physical.
But we already know that singularities don't really exist, they just represent a point where our theory has broken down and we need to backup to before things broke and try to find alternatives.
Therefore if you ask me if I believe that singularities and ringularities are physical? I would tell you that I believe they are not.
The neat thing about LQG or Loop Quantum Gravity is that it does in fact unify GR and QM without introducing anything too funky like curled up dimensions and strings. All you have to accept is that spacetime is quantized i.e. pixelated just like the rest of quantum mechanics. In otherwords, the solution to zeno's paradox is that there is a smallest small, both a smallest distance and a smallest time.
If you accept that, then it becomes easier to understand accept different predictions that don't suffer from zeno's paradox.
There are solutions in LQG that show quite logically that as densities increase towards the planck limit the Heisenberg uncertainty principle would kick in. This would provide a counter pressure thereby stopping collapse and triggering a rebound. This means that if you were to cross the even horizon you would not find a singularity nor a ringularity, you would find maximally dense object called a planck "star", although we should probably rename it since it's not a star it's just a big ball of maximally packed material. This is something that is so dense, it would pass through neutronium (the stuff a neutron star is made of), as though the neutronium were glass, utterly annihilating it. Whatever you want to call it, however you want to describe it, by the time you cross the event horizon, that object would likely be in the process of rebounding.
All planck "stars" are expected to eventually rebound. That process takes about 14 to 20 billion years due to the way in which time slows (due to curvature of spacetime), meaning that we should start seeing primordial blackholes begin rebounding into whiteholes soon. It is thought that some high intensity GRBs such as the one that produced the OMG particle (a proton moving so fast it had the same mass as a baseball), could in fact be the result of this, since the rebound would result in instantaneous release of everything that was previously shielded by the event horizon.
In otherwords, EVERYTHING escapes a blackhole eventually!
But it's probably going to be converted into gamma rays in the process :)
(Score: 3, Funny) by Anonymous Coward on Sunday October 27 2019, @02:52PM
Summary of above...
It's a wibbily wobbly timey wimey thing.
(Score: 2, Interesting) by RandomFactor on Sunday October 27 2019, @03:14PM (2 children)
Hrrrmmm.
Spatial Expansion/Big Rip? (not helpful)
Shooting stars past the black hole to get it rotating (I brought my own cue.)
Universe age = 13.8 Billion years old
Lower bound = 14 Billion years
"Soon" = 200 Million years. Darn, not 'hang out on the patio with your Meade' soon.
В «Правде» нет известий, в «Известиях» нет правды
(Score: 2) by Fluffeh on Monday October 28 2019, @02:08AM (1 child)
I see two Red Dwarf quotes in this thread.
All we need now is for the order of the threading to go haywire and we have a perfect White Hole story arc in the making.
"Oh someone punch him!"
(Score: 2) by GreatAuntAnesthesia on Monday October 28 2019, @11:59AM
Well, the thing about a Black Hole – it’s main distinguishing feature – is it’s black. And the thing about space, your basic space colour... is black. So how are you s’posed to see them?
(Score: 0) by Anonymous Coward on Sunday October 27 2019, @05:18PM
thx for post!
(Score: 2, Touché) by Anonymous Coward on Sunday October 27 2019, @05:51PM
The wow particle had the kinetic energy of a thrown baseball, not the mass. If it had the mass of a baseball the impact would have been as devastating as a largish nuclear bomb.
(Score: 2) by krishnoid on Sunday October 27 2019, @11:01PM
One difference is that one thing worse than spotting a wormhole is only finding half a wormhole :-)
(Score: 1) by RandomFactor on Sunday October 27 2019, @02:40PM (4 children)
All you get from inside a black hole as I understand it is gravity and ELF radiation (Extremely long wavelength radiation from particles able to tunnel through the event horizon, think wavelengths of millions or billions of km long).
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(Score: 2) by Mojibake Tengu on Sunday October 27 2019, @03:24PM (1 child)
Why some gravity escapes the black hole at all? Is the gravity faster than light?
Respect Authorities. Know your social status. Woke responsibly.
(Score: 1) by RandomFactor on Sunday October 27 2019, @04:39PM
I think answering this would require integrating gravity into Quantum Mechanics.
I'm not qualified :-)
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(Score: 2) by The Mighty Buzzard on Sunday October 27 2019, @03:57PM (1 child)
The redshifted into invisibility EM waves, as I understand it, don't come from within the event horizon but mark the absolute edge of it. They get pulled on so hard that nearly every bit of energy is removed (thus lengthening the wavelength). Beyond "nearly every bit" is "every bit".
My rights don't end where your fear begins.
(Score: 1) by RandomFactor on Sunday October 27 2019, @05:05PM
There are a couple of scenarios
1) A particle-antiparticle pair pops into existence, one on either side of the event horizon. The one outside escapes, the other falls in.
2) A particle within the event horizon 'tunnels' outside.
My reading was that #2 requires ELF wavelength initially (a function of the black hole event horizon radius) to tunnel out.
Then you throw on massive red-shifting trying to get away from the event horizon regardless.
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(Score: 3, Informative) by The Mighty Buzzard on Sunday October 27 2019, @03:51PM (8 children)
Gravitational waves don't come out of a black hole. They're caused by a body of mass moving through spacetime and are a function of the spacetime being passed through rather than the body that causes them to be created. The preceding is predicated on the assumption that gravitons are not a thing.
My rights don't end where your fear begins.
(Score: 2) by Common Joe on Sunday October 27 2019, @04:34PM (6 children)
But that's just it. Any two mass bodies interacting with each other should cause gravitation waves. If one mass is affected by another, it should cause a gravitational wave. If gravity can pass through a black hole, then gravitational waves can too. If gravitational waves can pass through, then information can also. At least, that is where I'm coming from.
(Score: 3, Informative) by maxwell demon on Sunday October 27 2019, @04:48PM (2 children)
But gravitation doesn't pass black holes. It's not that a gravitational body produces a field that then in some way flows outward. Rather, the massive body is surrounded by a gravitational field. The field outside the black hole always was outside the black hole; it never crossed the horizon.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by Common Joe on Sunday October 27 2019, @06:18PM (1 child)
That's from the summary. To my knowledge, wormholes must be inside of the blackhole (because they are caused by the extreme gravitation). If wormholes are thought to be generated outside of the black holes that create them, that would be news to me.
(Score: 2) by maxwell demon on Sunday October 27 2019, @10:49PM
The summary speaks about wormholes, not black holes.
If (both sides of) the wormhole were inside a black hole, it would obviously not traversable (unless you count being in another black hole as traversal). But anyway, a wormhole inside a black hole would not be detectable anyway, so if we can detect a wormhole, it must be outside of a black hole.
Also, extreme gravitation does not necessarily equal black hole. For example, at the big bang there was extreme gravitation, but no black hole. And in theory, there could exist "naked singularities" that are not hidden behind horizons, thus aren't black holes either. And finally, a white hole is the exact opposite of a black hole, but certainly also a region of extreme gravitation.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 4, Interesting) by The Mighty Buzzard on Sunday October 27 2019, @05:04PM (2 children)
Wormhole != black hole. Very different things. A black hole is what we call it when spacetime curls in on itself and essentially vanishes as part of this universe. A wormhole is when spacetime also gets bent wicked hard but in a different way so as to cause two points quite distant from each other to have a shortcut.
Now as to gravitational waves through a wormhole being a shortcut around relativity? Sure. If you could control the orbits of a pair of black holes or other sufficiently massive bodies. But for that matter, electromagnetic radiation going through a wormhole would experience the same shortcut and be slightly easier to accomplish than changing the orbits of a pair of black holes billions or trillions of times per second.
I'm not even sure gravitational waves are theoretically limited to C anyway being as they're a ripple in the fabric of spacetime rather than a particle or wave traveling through it. Hell, I'm not sure applying the term "speed" to gravitational waves makes sense since spacetime is what the wave is made of and spacetime is the thing moved through rather than something that moves. I mean you could get two distant points and measure an apparent speed of propagation between them but that's not something moving through spacetime but spacetime itself moving, so it would be a useful fiction rather than the truth.
My rights don't end where your fear begins.
(Score: 2) by Common Joe on Sunday October 27 2019, @06:28PM (1 child)
I get that, but wormholes are generated by black holes, i.e., they exist at the center of the black holes. Or did I miss something important?
Gravitational waves travel at light speed. I'm too lazy to look it up, but the article about our gravitational wave detectors finally becoming operational and immediately detecting gravitational waves mentions that. And to be clear: the gravitational waves we picked up may have come from a black hole shredding a star, but gravitational waves are generated by any two mass bodies doing a dance with each other and changing their orbit. Our moon should be creating these waves as the moon recedes from the earth. Our technology simply can't distinguish it from the rest of the background noise.
I'll admit, I don't know what a black hole will do to the gravitational waves, but if we think these things can be detected after going through a black hole (because it's strong enough to change the orbit of a star according to TFS), then information can escape a black hole. And that caught my attention.
Either this story is bunk, there's something very interesting hidden in the article, or I'm ignorant about something. I'm trying to figure out which one it is.
(Score: 2) by The Mighty Buzzard on Sunday October 27 2019, @10:05PM
We'd either be unable to detect them "moving" faster or we'd detect them as coming from the opposite direction. But they have no matter or energy to be limited to C, so there's no reason the effect should be.
My rights don't end where your fear begins.
(Score: 2) by JoeMerchant on Sunday October 27 2019, @07:41PM
What "bothers" me about this hypothesis is the idea that gravitational waves propagating through a (presumably small-ish) wormhole would perturb stars orbits at a similar order of magnitude as gravitational waves sourced in the relatively wide open 3D of "normal" space.
I would expect quite a bit of "small aperture" effect from the wormhole, although what a 3D aperture looks like is a little trippy just to consider.
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