In Test of Relativity Theory, Superaccurate Atomic Clocks Prove Your Head Ages Nanoseconds Faster than Your Feet
Relativity experiment is the most accurate yet Einstein first figured out that time moves at a different rate depending on how fast you're moving, and depending on how close you are to a gravitational field. And scientists have already shown that time moves faster at higher elevations - clocks on a rocket move slower than clocks on Earth, for instance. By this logic, astronauts are actually time travelers. Now, scientists have shown this time difference in action on the smallest scales yet - clocks move at different speeds on a staircase. In a study published today in the journal Science, researchers at the National Institute of Standards and Technology explain that a one-foot difference in altitude between two clocks caused them to tick at slightly different rates. The optical clocks can even measure changes in the passage of time caused by a 20-mile-per-hour speed difference. The clocks are based on the oscillations...