Physics professor searches for extra dimensions

Greg Landsberg's search for extra dimensions is attracting attention within the physics world and against the backdrop of a public that is fascinated by the ideas of poking through to extra dimensions and black holes.



By Janet Kerlin

If scientists find extra dimensions, they might solve the parking problem, assistant professor Greg Landsberg likes to say with a deadpan look.

Really, though, if extra dimensions do exist, the discovery would be the greatest since we learned the earth is not flat, he said.

"It certainly would change our picture of the universe," Landsberg said. "If correct, it would explain our nature in all its mystical beauty and completeness."

Landsberg's search for extra dimensions is attracting attention within the physics world and against the backdrop of a public that is fascinated by the ideas of poking through to extra dimensions and black holes.


Greg Landsberg, left, believes that if there are extra dimensions, they would be curled

At the American Physical Society annual conference in April, Landsberg reported that he and other scientists have come the closest yet to proving or disproving whether dimensions exist beyond the ones we know of: length, height and depth, and a fourth one, time.

"We have a method of looking and the first results from data," Landsberg said. "The results are still negative, but very promising in that they show our sensitivity to the size of the extra dimensions."

If there are extra dimensions, Landsberg and others believe they would be curled, with a radius smaller than 1 mm, but still large enough to have an effect on gravity that could be measured.

Landsberg looks for evidence of extra dimensions by smashing protons and antiprotons together in the world's largest particle accelerator at the U.S. Department of Energy's Fermilab in Batavia, Ill. Landsberg sits at the accelerator's DZero detector, where scientists try to detect particles resulting from the collisions.

To prove the existence of extra dimensions, the scientists were looking for increased gravitational interaction between pairs of photons produced during collisions.

Although they found no such increased gravity, they did show that they were able to set stricter limits on the size of the dimensions than those set by other experiments.

Still, Landsberg remains energized by the possibility of extra dimensions. More experiments in the accelerator will be conducted next year. If they fail to detect extra dimensions, then additional experiments will be conducted at an even higher-energy accelerator under construction at the CERN lab on the border of France and Switzerland near Geneva. The collider is being funded by a group of 15 countries and is to be completed in about six years.

"It's just a matter of time and energy for us to either find these extra dimensions or to rule out this theory completely," Landsberg said.

Landsberg has written an article explaining his work in the April 28 edition of Ferminews.