A clock that can detect tiny shifts in the flow of time itself
A comment of the article by Joey N correctly notes that:<p><i>Right now, on the top of Mount Everest, time is passing just a little bit faster than it is in Death Valley. That's because speed at which time passes depends on the strength of gravity. Einstein himself discovered this dependence as part of his theory of relativity, and it is a very real effect.</i><p>"Just to be clear, the clock in Death Valley appears to run slowly from the point of view of the eagle-eyed observer standing on top of Everest.<p>To a person in Death Valley, the clock appears to tick at precisely the rate it would appear to tick if both person and clock were on top of Everest."