“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,” Dejan Stojkovic, professor of physics, University at Buffalo, who proposes in a theoretical study, that perturbations in the orbit of stars near supermassive black holes could be used to detect wormholes forming passages connecting one area of our universe to a different time and/or place within our universe, or to a different, alien universe.
But in a paper published on Oct. 10 in Physical Review D, physicists describe a technique for detecting these bridges, focusing on spotting a wormhole around Sagittarius A*, the black hole at the heart of the Milky Way galaxy.
“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 Stojkovic about the possibility of detecting a wormhole at Sagittarius A*. “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.”
To Make it Traversable –“Magic Needed”
Stojkovic conducted the study with first author De-Chang Dai, PhD, of Yangzhou University in China and Case Western Reserve University. Stojkovic notes that if wormholes are ever discovered, they’re not going to be the kind that science fiction often envisions.
“Even if a wormhole is traversable, people and spaceships most likely aren’t going to be passing through,” he says. “Realistically, you would need a source of negative energy to keep the wormhole open, and we don’t know how to do that. To create a huge wormhole that’s stable, you need some magic.”
While there is no experimental evidence that these passageways exist, observes Stojkovic, they are “a legitimate solution to Einstein’s equations.”
The research in Physical Review D focuses on how scientists could hunt for a wormhole by looking for perturbations in the path of S2, a star that has a 16-year orbit around Sagittarius A*.
“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.”
In October of 2012, another star was detected in an earlier study by UCLA astronomers that orbits Sagittarius A* in a blistering 11-and-a-half years—the shortest known orbit of any star near this black hole. The star, known as S0-102, may help astronomers discover whether Albert Einstein was right in his fundamental prediction of how black holes warp space and time, said Andrea Ghez, head of the discovery team and a UCLA professor of physics and astronomy.
“It is the tango of S0-102 and S0-2 that will reveal the true geometry of space and time near a black hole for the first time,” Ghez said. “This measurement cannot be done with one star alone.”
Though the wormhole paper focuses on traversable wormholes, that because gravity is the curvature of spacetime, the technique it proposes could detect the presence of either a traversable or non-traversable wormhole, Stojkovic says.
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.
Image credit: Black Hole top of page, ESO/GRAVITY CONSORTIUM/L CALÇADA