By Ron Cowen
Some stars may contain wormholes, throatlike tunnels connecting distant points in spacetime, a team of physicists proposes. But other researchers are having a hard time swallowing the idea.
“It’s a nice piece of speculative work, but it is speculation,” says theoretical physicist Matt Visser of Victoria University of Wellington in New Zealand.
In an article posted online at arXiv.org February 25, physicist Vladimir Folomeev of the Institute of Physicotechnical Problems and Material Science in the Kyrgyz Republic and his colleagues suggest that pairs of stars could be joined by wormholes constructed of an exotic material known as “phantom matter.” Strictly hypothetical, the stuff has been proposed as a possible explanation for the accelerating expansion of the universe. Its exotic properties could also enable phantom matter to keep a wormhole propped open.
“I am pretty sure that once you admit exotic matter of some suitable kind, you can mathematically construct a star with a wormhole inside,” comments relativity theorist Dieter Brill of the University of Maryland in College Park.
Actually seeing one is another thing entirely. It’s possible, says Folomeev, that a stellar wormhole might generate signals that telescopes could record. In general, an ordinary star and one with a wormhole at its center would look the same to a distant observer. But if the wormhole has a strong enough influence, it might alter properties such as the mass or size of the stars in a nonstandard way. And if the wormhole is short, so that the two stars it links don’t lie far apart, an observer might see another unusual signpost — two closely spaced objects with nearly identical properties.
The team performed preliminary calculations suggesting that such a configuration might be stable against relatively simple disturbances to the system, supporting the possible existence of such a beast. However, the researchers acknowledge that their analysis isn’t complete.
“They seem to have done a serious analysis of the system, but they haven’t claimed to have shown stability, as would be necessary to take the model seriously,” comments theoretical physicist Robert Wald of the University of Chicago.
In their paper, Folomeev and his colleagues suggest that the matter in the wormhole would slosh around, generating astrophysical fireworks in the process. Oscillations in which different parts of the material move at different velocities could lead to collisions that might be energetic enough to produce gamma-ray bursts, the most powerful explosions in the universe.
For now, this is just an idea that still must be confirmed by further calculations, says Folomeev.
Although it’s unclear whether or not the stellar wormhole model will collapse under scrutiny, says Brill, “I am generally in favor of calculating models that a priori seem far-fetched and wild.”
