How to add 90billionths of a second to your life . . . live in the basement: Scientists prove time really does pass quicker at a higher altitude



Tick tock: The atomic clock calculated that for every 12 inches of elevation, 90 billionths of a second are added to a lifetime

It's taken a century but scientists have finally prove that Albert Einstein was right - time really does past more quickly if you stand on a step ladder.

In a bizarre experiment using the most accurate atomic clocks ever invented, researchers showed that clocks run faster if they are raised by just 12 inches.

However, anyone hoping that a lifetime living in a basement is the secret to longevity will be disappointed.

The effect is so small that it would add just 90 billionths of a second to a 79 year life span.

The extraordinary experiment - published today in the respected journal Science - demonstrates one of the strangest consequences of Einstein's theories of relativity.

Einstein's work famously showed that time is relative. In 1907 his General Theory of Relativity showed that clocks run more quickly at higher altitudes because they experience a weaker gravitational force than clocks on the surface of the Earth.

The phenomenon - called gravitational time dilation - has been demonstrated by putting atomic clocks on jumbo jets and flying them at high altitudes.



Just as Einstein predicted, clocks flown at 30,000 feet run faster than those left behind on the ground.

Gravitational time dilation can be seen in global positioning satellites which need to have their clocks regularly adjusted.

It also means that your head ages more quickly than your feet, that people living on the top floor of a tower block age more quickly than those on the first floor - and that time passes more slowly for people living at sea level than it does for those on mountains.

Mount Everest: Time will pass quicker for inhabitants of the Nepalese mountain range and other high spots across the globe according to the scientists

The new study - carried out by the National Institute of Standards and Technology in Boulder, Colorado - measured the effect at a scale of just one foot using the world's best atomic clocks.

The clocks keep time based on the "ticking" of a single aluminium ion as it vibrates between two energy states. The clocks are so accurate they lose or gain less than one second every 3.7 billion years.

In one experiment, the researchers raised one of the experimental clocks by 12 inches.

Proved right: Albert Einstein's General Theory of Relatively showed that clocks run more quickly at higher altitudes because they experience a weaker gravitational force

Sure enough, the higher clock ran at a slightly faster than the lower clock, exactly as predicted,' said a spokesman for the NIST.

"The difference is much too small for humans to perceive directly - adding up to approximately 90 billionths of a second over a 79-year lifetime.'

The researchers, led by Dr James Chin-Wen Chou, then used the clocks to replicate another of Einstein's famous discoveries - the so-called twin paradox.

Just as time flows more quickly for an object under a weak gravitational force, it also passes more slowly as an object moves faster.

Einstein showed that if a twin leaves the earth in a rocket travelling at speeds close to the speed of light, when he returns to Earth he will be younger than the sibling left at home.

The researchers tweaked the charged atom at the heart of one of their atomic clocks so that it gyrated back and forth at speeds equivalent to several metres per second.

They found that the clock ticked at a slightly slower rate than the untouched clock.

The researchers say their work doesn't just demonstrate Einstein's Theories of Relativity.



They believe comparing atomic clocks could help measure the gravitational field of the Earth.

