The following press-release is originally from UC Irvine.
SEARCHING FOR A `SUBWAY TO THE STARS'
In an article published March 15, 1995 in the scientific journal Physical Review, John G. Cramer, with co-authors Gregory Benford, Geoffrey A. Landis, Matt Visser and Michael Morris, argue that the search for dark matter in the universe could be expanded to include exotic forms of dark matter such as wormholes, topological connections between separated regions of space-time that might be described as"subways to the stars."
The article, "Natural Wormholes as Gravitational Lenses," explains one theory underlying the possible existence of such objects and describes the gravitational lensing "signature" that might enable us to detect them. The proposal stems from a workshop on relativity and quantum mechanics sponsored by NASA.
"A 'wormhole' is a theoretical object permitted by Einstein's theory of general relativity, where distant regions of space are connected by a shortcut,"says Landis, a scientist at NASA's Lewis Research Center in Cleveland, OH, as well as an award-winning science-fiction author.
"Such wormholes could have been created in the distant past, in the time just following the 'big bang' that created the universe. What we discovered at the workshop was that if such wormholes did exist, they could be detected by the bending of light due to gravity, an effect known as the 'gravitational lens.' "
"Several research groups currently are using telescopes to monitor gravitational lensing events to search for massive compact halo objects (MACHOs) that have positive mass. They want to count these objects because they could explain the vast amount of dark matter in our galaxy, or perhaps the whole universe,"Benford explains. Gregory Benford is a professor of physics at the University of California Irvine, and also a highly-regarded science fiction writer.
[Sarfatti note: Benford and I were grad students together at UCSD in the late 60's. We once tried to work out a theory of photonic superfluids in which EPR photon pairs would Bose-Einstein condense in a nonlinear optical situation.
Benford's co-author, John Cramer has the "transactional interpretation of quantum mechanics" (see Fred Alan Wolf's books, "Star Wave", "Parallel Universes", and "Taking the Quantum Leap" for popular discussion of Cramer) in which an advanced wave from detection moves back in time to the preparation. The interference with the retarded wave going forward in time creates the Born probability density for something to actually happen.
Benford's book "Timescape" is about a future civilization contacting its past. Here I am suggesting that the recent observations of old stars in a young universe means that we are contacting our future descendents in our past light cone because they have used the wormholes to take their stars back to the past to escape the cosmic winter. One test of this idea of mine is to train the CETI antennas on these anomalous old stars!]
"So far, these experiments are not surprising anyone. They're turning up a reasonable amount of possible dark matter, but nothing that's going to solve the dark matter problem. But we believe that by paying just a little more attention, by analyzing the MACHO search data for evidence of what we like to call GNACHOs (Gravitationally Negative Anomalous Compact Halo Objects), there's a chance to make a really profound discovery."Wormholes provide one possible way to create astronomical objects of negative mass, according to theoretical calculations by Matt Visser, professor of physics at Washington University in St. Louis, Mo., and a co-author of the article.
"Wormholes, although allowed by the theory of relativity, are theoretically unstable," says Landis. "However, at the time of the formation of the universe in the big-bang, wormholes could have been stabilized by loops of negative mass cosmic string. If so, they would still be here, and it is be worthwhile to look for them. If we find one, the implications are enormous."
"According to theory, either end of a wormhole can swallow mass, ejecting it out the other end,"said Benford.
"But a wormhole mouth in a dense region of matter swallows mass faster than its other end, if that end is in a sparse region. Mass emerging from an end curves space-time oppositely. it's as though the end loses mass, finally reducing to zero mass and then to negative. Gravitationally, that negative end looks like a negative mass, maybe even a large, stable one."Expanding the current Optical Gravitation Lensing Experiment (OGLE) a collaborative project between the Warsaw University Observatory, Carnegie Observatory and Princeton University Observatory to search for these and other possible negative mass objects would be relatively simple, said Benford. This is because GNACHOs, if they exist, provide a distinctive light enhancement profile when passing between us and distant stars. This resembles the twinkling of starlight in the Earth's atmosphere.
"Ordinary mass causes the sudden brightening of a star image, exerting a gravitational refraction on the light, like a focusing lens," said Benford. "Ordinary mass causes a single peak in brightness because it focuses the light, but negative matter deflects the light rays, creating a shadowed umbra region where light from the source is extinguished. At the edges of the umbra the light rays accumulate to form what's called a caustic, giving a very large increase in light intensity in two visible peaks of brightness."All but one of the microlensing events observed by the OGLE project thus far exhibited the single brightness peak associated with ordinary matter. However, one event, OGLE #7, has exhibited very unusual light variations.
"So far this event which shows a double hump brightness peak has been attributed to a binary star, which are common,"said Benford.
"While it very well may be a binary star, the double peak also is similar to the signature we've predicted for a GNACHO. Therefore, I don't think we should just assume it's got to be binary and brush it off. If we look in greater detail, we just might find that it's an entirely different object."What would it mean if we were to discover a wormhole?
"A wormhole is like a subway to the stars; a method of going places that are spatially very distant instantaneously, and without contradicting the theory of relativity. You go in one end and you pop out somewhere else in the galaxy, or maybe in another galaxy,"said Benford.
"Finding one would completely change our view of how galaxies form, because it would mean that wormhole transport of mass from one part of the universe to another has been a significant evolutionary factor. It would mean that space-time is intimately connected in a way we didn't know; that the whole universe is knitted together and that's a profound result."But whether or not we find a wormhole, it's the search that's important, said Benford.
"The chances of negative mass wormholes being common are slim and nobody's going to get funded to go out and look for wormholes but the chance to find one as a bonus with data from existing dark matter experiments is enticing,"he said.
"Our goal is to say `Let's see if we can make an observation.' Because there are still lots of mysteries in the universe, and we shouldn't take for granted that we know what's in it."Geoffrey A. Landis, Ohio Aerospace Institute NASA Lewis Research Center
