|Link to The Independent|
"Einstein's theory of relativity states that time and space are not as constant as everyday life would suggest. He suggested that the only true constant, the speed of light, meant that time can run faster or slower depending on how high you are, and how fast you are travelling.
"Now scientists have demonstrated the true nature of Einstein's theory for the first time with an incredibly accurate atomic clock that is able to keep time to within one second in about 3.7 billion years – roughly the same length of time that life has existed on Earth.
"... What's really remarkable is that these studies show these incredibly small effects of relativity over such short distances. They have demonstrated graphically that, although we think of relativity as an esoteric theory of no relevance to everyday life, we can in fact show that it is really true that you will grow old marginally faster, if you stand just one step higher on a staircase."