Gravitational time dilation makes time slow down and speed up, based on location and spacetime. Your watch is creeping toward heirloom status faster than you can even understand.
One of the wildest implications from Einstein’s theory of relativity is the idea that gravity actually slows time down. This is why your watch would still probably run in a time warp, but it’s also why no one can quite define time satisfactorily.
Remember that relativity combines time with space into a universal scaffolding called spacetime, which is an actual material made out of actual stuff. Relativity also suggests that gravity has the ability to slow time down, and, in 2010, scientists were able to measure and prove it.
The idea is called gravitational time dilation. The theory basically says that time slows down as it nears a gravitational force.
So, with the earth being about 4.5 billion years old, the earth’s central core is about two and a half years younger than a city with high elevation like Boulder, Colorado.
Which makes Boulder a fun location for the National Institute of Standards and Technology.
Scientists there got their hands on the world’s most accurate atomic clocks to run some time tests.
These clocks are so advanced that they gain or lose less than one second every 3.7 billion years. They recorded that the clock positioned 1 foot above its test partner would age about 90 billionths of a second more every 79 years.
Yes, 90 billionths of a second in 79 years. Hey, it’s still something.
It’s got some odd implications. People living atop mountains age faster than people in valleys. Your watch ages faster than your boots.
And if it seems so infinitesimal as to be irrelevant, remember it next time you tap open your GPS.
Gravitational time dilation is used by the atomic clocks on global positioning satellites to make sure we can navigate within our experience of spacetime—without having to confront how severely limited our understanding of it really is.