Rare space experiment gives clues about the fundamental structure of the universe

		IMAGE: In this illustration, one photon (purple) carries a million times the energy of another (yellow). Some theorists predict travel delays for higher-energy photons, which interact more strongly with the proposed... Click here for more information.

A physics experiment using a super-fast explosion in a galaxy 7.3 billion light-years away has given scientists rare experimental evidence about the fundamental structure of space and time. The experiment was performed by a team that includes astrophysicists at Penn State University, who used NASA's Fermi Gamma Ray Space Telescope to study particles from the explosion moving at nearly the speed of light. The experiment confirmed aspects of Einstein's theories of gravity, which unite space and time in the concept of space-time. The team's research is published in the current early-online edition of the journal Nature and will be published at a later date in the print edition.