By Kathryn Kopchik
LEWISBURG, Pa. — Eric Adelberger will give the talk, "Hidden Extra Dimensions and Short-distance Gravity," on Monday, March 2, at 7:30 p.m. in Room 268 of the Olin Science Building at Bucknell University.
The talk, which is free and open to the public, is part of the ongoing Phi Beta Kappa Lecture series at Bucknell.
Research on gravity
"Adelberger's a pioneer in finding new and creative experiments to test our theories of gravity. This is an important area of fundamental physics, since the origins of gravity are still mysterious," said Ben Vollmayr-Lee, associate professor of physics at Bucknell.
Of his talk, Adelberger says, "It is remarkable that small-scale experiments can address important open issues in fundamental science such as: 'Why is gravity so weak compared to all the other fundamental forces?' and 'What is the true number of space dimensions in the Universe?'
"String theory ideas (extra space dimensions and new particles) hint that the extraordinary weakness of gravity could be understood if Newton's Inverse-Square Law breaks down at distances less than 1 mm.
"I will review these ideas, explaining why the notion of more than three space dimensions is not ridiculous and then discuss the problems that must be solved before one can measure gravity at short distances."
Adelberger also will discuss the techniques used in recent experiments that studied gravity at separations down to 60 micrometers (approximately the diameter of a human hair). These reveal that any extra dimension must have a size less than 46 micrometers and constrain speculations about chameleons, a mechanism that was invented to "hide" string theory's many new particles.
University of Washington
Professor of physics at the University of Washington, Adelberger previously was a scientific associate at the European Organization for Nuclear Research (CERN) in Geneva.
A member of the National Academy of Sciences, he is a fellow of the Institute of Physics as well as of the American Physical Society and a recipient of the APS Bonner Prize for outstanding experimental research in nuclear physics. He holds his degrees from Caltech.
Adelberger's interest in gravity led him to found the Eöt-Wash Group that has made many technical advances in torsion-balance technology. These developments have led to extraordinarily precise experimental tests of Einstein's Equivalence Principle, measurements of Newton's constant G, searches for hidden extra dimensions by testing Newton's Inverse-Square Law down to distances smaller than a human hair, and sensitive tests of the isotropy of space.
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