A yarmulke-wearing Israeli physicist finds some wormholes' in conventional theories about the universe An Israeli physicist is punching holes in some commonly held assumptions about black holes.
Indeed, says Amos Ori, the perplexing celestial bodies might even provide future spacecraft with a shortcut around the universe.
The findings of Ori's research, conducted during a three-year postdoctoral fellowship at the California Institute of Technology in Pasadena, were published last summer in the academic journal Physical Review Letters and later reported in the prestigious periodicals Nature and New Scientist. Eventually, they could make stellar intellects like British physicist Stephen W. Hawking reexamine some notions about black holes.
A black hole is the term used to describe a large star that has folded in on itself, rendering the escape velocity from its surface greater than the speed of light.
Nothing that falls into a black hole - not even light - can ever escape it, physicists say.
Physicists have long suspected that objects sucked into black holes are obliterated once they reach the center, or singularity, of the cosmic vortexes. Physicists like Hawking and mathematicians like Roger Penrose of Britain speculated that at some point in the core of the black hole, matter shrinks to zero size, thrusting the density of matter and the curvature of space-time to infinity.
Then along came Ori, from Kibbutz Migdal Oz in the Etzion Bloc south of Jerusalem, a 35-year-old Orthodox Jew with a PhD in physics from the Hebrew University.
Like most other physicists, Ori had an idea of what happened to matter once an object crossed the "blue event horizon," or boundary, of black holes. But Ori, who witnessed his first lecture about black holes on TV as a tank corps reservist stationed near the Jordan River, wanted to know what happened to an object after it encountered a singularity.
"I was always amazed by the idea of an object which absorbs everything and cannot emit anything. I felt this was in some way contrary to the spirit of physics, where we are used to thinking there is a harmony in nature and a continuity of motion."
Ori was particularly struck by the improbability of motion itself coming to a complete cessation. "If a pendulum swings down, later it swings up. The total end-point of motion is not a common feature in physics.
"The paradox that especially intrigued me about singularities is that though nothing can leave the center, nothing can stay in it either. I wanted to know how that could be."
Ori's question could not be answered. There was no mathematics to describe a realm in which the known laws of nature do not apply, nor any way to experimentally observe what happens when an object encounters a singularity.
Not surprisingly, Ori couldn't find anyone at the Hebrew University prepared to act as the adviser on his proposed doctoral thesis. He now views that as fortunate, because it forced him to redefine his goals.
"Eventually, I defined my thesis as a look at the problem of gravitational collapse bringing about the formation of the black hole, which is something you can treat on the basis of traditional physical theory. It was close enough to my original interest so that I could study it and prepare myself to attack the singularity problem at the next stage."
The "next stage" turned out to be the provocative view of black holes developed at the California institute.
Some astronomers believe they have detected actual black holes; physicists like Ori deal mostly with mathematical models.
One of the earliest and simplest, a "Schwartzschild" black hole, is perfectly spherical and does not rotate. Under conventional physics an object that falls into such a body's singularity should be crushed into infinite density.
In his post-doctoral studies, Ori found himself contemplating more complex models. It is likely that most black holes do indeed rotate. What did this mean for its singularity? Is an object drawn into its maws doomed, or might it not somehow avoid cataclysm, perhaps even emerging somewhere else through a "wormhole" in space?
Ori's main finding, as reported in Physical Review Letters (and elaborated in a paper recently submitted to the same journal), was that the singularity within a swiftly rotating black hole is so weak that physical objects it encounters may not be crushed. Indeed, they may actually emerge intact somewhere else in the universe, confirming a notion once in vogue with physicists, who have since dismissed it, and science fiction writers.
Ori says there's a reasonable chance that such "wormholes" through space exist though where they may lead is anyone's guess.
Despite the fact that he is Orthodox, Ori spends little time speculating on the theological implications of his work. He's not bothered by traditional Judaism's view that the universe is about 6,000, and not billions of years old, nor does he find it particularly significant.
"Our ideas of what is normative Judaism are changing," he says, "but so is our grasp of modern cosmology. I do not accept Hawking's point of view that our understanding of cosmology precludes the idea of a Creator for the universe," he said.
"The structure of our cosmological theory is far from complete, and it will change countless times, and in ways we can't imagine, before we can ever begin to make such an assumption."