Anyone visiting the International Space Station from 2014 won’t have any excuses for poor timekeeping, with the cold-atom clock being sent up there as part of the Atomic Clock Ensemble in Space (ACES) project.
Compared to Earth’s clocks, which keep time thanks to GPS satellites, the PHARAO (Projet d’Horloge Atomique par Refroidissement d’Atomes en Orbite) clock will be 100 times more accurate thanks to the unique way it works in space.
Due to a little thing known as gravity, caesium clocks don’t work so well down here—but up in space, where microgravity abounds, the caesium atoms help measure time better as they don’t bounce back so quickly. Six orthogonal laser beams help cool the caesium atoms down, so the quality of measurement is far greater.
It’s the first time experiments like this have taken place in space, so a lot of physicists are hoping they can pull it off and learn more about the Gravitational Frequency Shift, Time Variation of the Fine Structure Constant, and Test of Special Relativity amongst other things. [ESA via New Scientist]
Image Credit: Ckaiserca
