Now, a team led by Holger Müller of the University of California, Berkeley, has measured the time-shifting effects of gravity 10,000 times more accurately than ever before. They show that gravity's effect on time is predictable to 7 parts per billion (H. Müller, A. Peters and S. Chu Nature 463, 926–929; 2010). And they did it using two laboratory clocks with a height difference of just 0.1 millimetres — a set-up that seems quaintly small in this day of big physics. "Precision experiments on a tabletop are not something of the past," says Müller, whose research team consisted of Achim Peters of the Humboldt University of Berlin and Steven Chu, the US Secretary of Energy.
Friday, February 19, 2010
The confirmations of Eintein's General Relativity get more and more precise. This is extraordinary: