Boffins at UC Berkeley have managed to confirm one of Albert Einstein's most revolutionary theories - that time flies when you are having fun.
While there has been a number of tests of Einstein's theory of general relativity to prove that it works, Holger Müller, a physicist at UC Berkeley, together with Steven Chu at Lawrence Berkeley National Laboratory wanted to test the accuracy of the work.
For his theory to work, Einstein required that the tug of gravity would make a clock slow down.
Writing in the popular science rag Nature, Müller and Steven Chu, have been applying tests to quantum mechanics.
The theory is that under the laws of quantum mechanics, everything in the universe, including light itself and all matter, has the properties of both particles and waves, properties that can't be seen at the same time.
Müller and his colleagues used the oscillation of caesium atoms vibrating as waves at a million billion billion times a second while a carefully tuned laser flashed at the vibrating wavelike atoms.
Using Einstein's concept of space-time, the particles pushed upward experienced time passing swiftly, while the particles that lay sunken in the Earth's gravitational well experienced time passing normally.
The upshot is that time flies when a laser is having fun. It also flies during drinking up time, although that is more to do with the principle of uncertainty.