U scientist finds nothing can be something special

His discovery of a gigantic emptiness in space could shed light on how we got here.

By Maura Lerner, Star Tribune

Last update: August 24, 2007 - 9:25 PM

Prof. Lawrence Rudnick is an expert on Nothing. He even teaches a class on Nothing. So it should come as no surprise that he may have found the biggest expanse of nothing in the universe.

On Friday, Rudnick, an astronomer at the University of Minnesota, was fielding questions about his latest research, on what appears to be a gaping hole in the universe. Talk about the vast emptiness of space. This hole is 6 billion trillion miles wide. No stars, no galaxies, no ... nothing.

His findings have caused a buzz in scientific circles and made headlines from New York to London. Some of the reaction has been skeptical, but that doesn't bother Rudnick. "We are in the business of discovery, of doing research that is exciting, mind-blowing," he said. "So when there's a discovery like this, it's really just fun."

Rudnick, who has taught at the University of Minnesota since 1979, announced his discovery Thursday, and by Friday morning he was appearing live on British radio. Fortunately, the 58-year-old astronomy professor, once a consultant to PBS' Newton's Apple, has a knack for making the most complex subjects understandable. But he only got 2½ minutes on the BBC. "It was a little nerve-wracking," he admitted.

As a scientist, Rudnick has long been fascinated by the concept of empty spaces. In a freshman seminar, called "Nothing," he invites guest speakers to talk about how the concept is used in art, design, math and medicine (the placebo effect). He talks about memory loss, blindness and spiritual emptiness. "Nothing," he says, "is everywhere."

A focus on the 'cold spot'

In the sky, Rudnick says, astronomers have known for some time that there are vast empty spaces, devoid of planets or stars or much else. But they never imagined anything this large before. The new-found "hole in the universe," he said, is 1,000 times larger than any previously discovered.

"In our own Milky Way Galaxy, we have 100 billion stars," Rudnick said. "If we were to go off in a spaceship ... traveling at the speed of light, you would only have to go a few years before you find another star." But that's nothing compared with the newly discovered space gap. "What we found is a place where you'd travel for a billion years before you found another concentration of mass. It would be a very boring journey of a billion years."

This big void, for you stargazers, is in the constellation Eridanus, near the foot of Orion. Not that you can see it, though. It's 6 to 10 billion light years away.

Rudnick and his colleagues, associate Prof. Liliya Williams and graduate student Shea Brown, studied telescopic images of the sky taken by the National Radio Astronomy Observatory in New Mexico. And they focused on what's called a "cold spot," where scientists had detected a puzzling drop in temperature in the background radiation of the sky.

Those "cosmic microwaves" are remnants of the Big Bang, which created the universe billions of years ago.

Rudnick and his team concluded the radio waves would lose energy, and cool down, when traveling through empty space. And they calculated that the "cold spot" stretched for a billion light years, according to their study, which will be published in a future issue of Astrophysical Journal.

Big, but no black hole

That's a big hole, not to be confused with a black hole, notes Rudnick, who is secretary of the Minnesota Planetarium Society. Black holes contain extremely dense matter. "The hole in the universe that we found, as best we can tell, is devoid or almost empty of matter in any form," he said.

Back on Earth, the discovery may seem a bit abstract. "It's not going to be tomorrow's pacemaker or anything like that," Rudnick said. "It is, however, part of the story of how we got here."

If correct, he said, it could shed new light on how the structure of the universe took shape, with its galaxies and planets and stars. It is, he said, "one of the hot topics in cosmology."

On the other hand, Rudnick admits, his team could be wrong, and "people will find that we misinterpreted the data."

As scientists, he said, "that's what keeps us awake at night."

Maura Lerner • 612-673-7384

Maura Lerner • mlerner@startribune.com

Comment on this story | Be the first to comment | Hide reader comments

Blog: Patent Pending

Bits of other stuff

AbbeyMoor Medical of Parkers Prairie has received pre-market approval from the Food and Drug Administration to sell “The Spanner,” a stent that treats men suffering from urinary problems because of a blocked prostate. Catchy name for a stent. Very vivid imagery. TST Media, a Minneapolis-based software company that specializes in Websites for amateur sport teams, said it [...]