Physicists Confirm Einstein's Time Dilation Theory With Unprecedented Accuracy
After more than a century, Einstein's theory of relativity is still confirmed time and time again. Physicists from institutions in Germany and Canada have proven, with unprecedented accuracy, that time moves more slowly for a moving clock than a stationary one.
Albert Einstein is credited with formulating the theory of time dilation. In his theory of relative velocity time dilation, a tenet of special relativity, he posited that clocks would appear to tick more slowly in relation to an observer in an inertial frame of reference. In other words, if one person is on Earth and another is in a high-speed spacecraft, then the astronaut would age more slowly compared to his or her non-accelerating counterpart.
Time dilation has been experimentally confirmed before, but never with this level of accuracy. For this experiment, the researchers used a moving clock made of lithium ions, accelerated to one-third the speed of light, as well as a clock made of stationary lithium ions. The transitions of the electrons as they jumped to and from different energy levels served as the "ticks."
"It is nearly five times better than our old result and 50 to 100 times better than any other method used by other people to measure relativistic time dilation," said study co-author Gerald Gwinner, a physicist at the University of Manitoba.
Understanding relative velocity time dilation has enormous implications for space travel. It has already been observed that NASA astronauts age .0007 seconds slower every six months that they're in space. (Although, according to Einstein's theory of gravitational time dilation, the decrease in gravity in the space station would cause time to speed up, astronauts still age slower than Earth-bound people because the two effects are not equal in magnitude.) Although this effect is insignificant to the point of being negligible, at higher speeds the effect would be much more dramatic. At a constant acceleration of 1 g (where g is the standard acceleration from gravity), astronauts could explore the entire known universe in a human lifetime, and return to Earth billions of years into the future. A version of this scenario occurred in the original Planet of the Apes, in which space travelers were able to reach the titular planet that was many lightyears away while only aging 18 months, as a result of time dilation.