title: World Year of Physics: a direct test of E=mc2.
abstract: One of the most striking predictions of Einstein's special theory of relativity is also perhaps the best known formula in all of science: E=mc(2). If this equation were found to be even slightly incorrect, the impact would be enormous--given the degree to which special relativity is woven into the theoretical fabric of modern physics and into everyday applications such as global positioning systems. Here we test this mass-energy relationship directly by combining very accurate measurements of atomic-mass difference, Delta(m), and of gamma-ray wavelengths to determine E, the nuclear binding energy, for isotopes of silicon and sulphur. Einstein's relationship is separately confirmed in two tests, which yield a combined result of 1-Delta(mc2)/E=(-1.4+/-4.4)x10(-7), indicating that it holds to a level of at least 0.00004%. To our knowledge, this is the most precise direct test of the famous equation yet described.
authors.affiliation: Research Laboratory of Electronics, MIT-Harvard Center for Ultracold Atoms, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. rainville@alum.mit.edu
authors.forename: Simon
authors.initials: S
authors.lastname: Rainville
authors.forename: James K
authors.initials: JK
authors.lastname: Thompson
authors.forename: Edmund G
authors.initials: EG
authors.lastname: Myers
authors.forename: John M
authors.initials: JM
authors.lastname: Brown
authors.forename: Maynard S
authors.initials: MS
authors.lastname: Dewey
authors.forename: Ernest G
authors.initials: EG
authors.lastname: Kessler
authors.forename: Richard D
authors.initials: RD
authors.lastname: Deslattes
authors.forename: Hans G
authors.initials: HG
authors.lastname: Börner
authors.forename: Michael
authors.initials: M
authors.lastname: Jentschel
authors.forename: Paolo
authors.initials: P
authors.lastname: Mutti
authors.forename: David E
authors.initials: DE
authors.lastname: Pritchard