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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, @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.