Time is not constant… (Picture: Getty/iStockphoto)
If you just spent all day watching the clock and waiting for 5pm, we suggest you find a job in an office at the top of a skyscraper.
Why? Because the higher up you are, the faster time moves.
That might sound impossible, but it’s true. Known as time dilation, it is a central principle of Albert Einstein’s theory of general relativity.
To prove it, scientists at the National Physical Laboratory (NPL) conducted an experiment at the top of 22 Bishopsgate, the tallest building in the City of London at 278 metres.
The team placed a highly accurate atomic clock on the 61st floor of the glass skyscraper, and kept its twin in the NPL Teddington, southwest London.
When the pair were reunited 43 days later, the clock from Bishopsgate had gained an additional 100 nanoseconds – well, plus or minus 30 – proving without a doubt that time moves faster in higher offices.
22 Bishopsgate (Picture: Brendan Bell)
Atomic clocks – not small
Good if you’re in a rush to get to the pub on a Friday.
Of course, the difference is miniscule – you’d have to spend around a million years on floor 61 to gain a second on the people at street level, but it’s still pretty mind-bending stuff.
It also means people who live in penthouses or work in the fanciest offices at the top of the building are ageing faster, something to drop into conversation if they’re ever being smug.
Dr Setnam Shemar, the principal scientist at NPL behind the demonstration, explained the principle behind the experiment.
‘Einstein’s theory predicts that time does not flow at the same rate everywhere, and that where gravity is stronger, time passes more slowly,’ he said.
‘For example, depending on where a person, or in this case, a clock, is within a gravitational field, that person or clock would experience time passing at a different rate than that of someone or a clock at a different position.
‘The influence of gravity on an object increases the closer it is to the earth’s surface. In this demonstration, time on the ground at NPL was passing slower than on the 61st floor at 22 Bishopsgate, consistent with gravity’s influence being slightly stronger on the ground.
‘Following the same principles, around a black hole in space, which has a very large mass and therefore very strong gravity, time slows down much more.’
Dr Leon Lobo (Picture: Lloyd England)
Dr Leon Lobo, head of NPL’s National Timing Centre (NTC) programme, added: ‘Many aspects of UK industry and society rely on precise time, an invisible utility. Whether it’s at home on our devices, synchronising the telecoms and energy networks, or in the finance industry where the accuracy of timestamps is unfeasibly fine – just 100 microseconds for high-frequency trading.
‘The demonstration amplifies the critical role of NPL in managing the UK’s time, developing the next generation of quantum clocks, and ensuring we have resilient time for the future.’