Blayne Heckel
Professor, University of Washington
Torsion balance tests of gravity at short distances & spin coupled forces
Abstract: There are a growing number of speculations that the inverse square law of gravity may break down at sub-millimeter length scales. The extra spatial dimensions and scalar particles of string theory as well as some theories that try to account for dark matter and dark energy through modifications of Newtonian gravity lead to inverse square law violations. We are performing torsion balance measurements of the gravitational attraction between masses that are separated by less than 100 microns and have completed 3 sets of measurements. Our experiment will be described and the data presented. A second torsion balance has a pendulum with 1/10 of a mole of polarized electrons and essentially no magnetic moment. This pendulum has been used to search for a violation of rotational invariance as well as for the existence of gravitational strength spin coupled forces. Our recent results will be presented.
Ph.D. 1981 -- Harvard, under supervision of Norman Ramsey, measuring parity-violating neutron spin rotations and the neutron electric dipole. Joined University of Washington in 1983 to study parity and time reversal symmetry violation in atoms. Began torsion balance experiments in 1986 to test 5th force hypothesis.
Location: Applied Physics, room 200 (AP 200)
Wednesday, June 7, 2006, 4:00 – 5:30 pm
Light refreshments available 4pm; Presentation begins 4:15pm. Open to all.
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view a list of past seminars, visit the HEPL/KiPAC