The confirmations of Eintein’s General Relativity get more and more precise. This is extraordinary:
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.