On Wednesday’s edition of his popular “Star Talk” radio show, astrophysicist Neil deGrasse Tyson explained how gravity affects the flow of time and how time passes on different planets with different gravitational fields.
A listener wrote in to “Star Talk” to ask if it’s the same time everywhere in the universe. Space flights and the International Space Station are all on Houston time because “that’s who they talk to,” but, the reader asked, does time move at the same rate everywhere?
“Different parts of the universe are moving at different rates,” deGrasse Tyson said, “and time has some relative aspects to it. For example, the GPS satellites, the clocks on them tick at a different rate than clocks on Earth’s surface because when you move far away from the source of gravity, your time speeds up.”
“So,” he continued, “the clocks on the GPS satellites are not ticking at the rate of the clocks that they are informing down here on Earth. The military puts a correction into the clock time of a GPS satellite so that it matches the time we need it to have here on the Earth’s surface.
Therefore, depending on where you are in relation to a gravitational force, your clock is ticking slightly differently than those located closer to the source.
Co-host Eugene Mirman then asked, “Okay, so what time is it on Jupiter?”
An interesting way to answer that question, said deGrasse Tyson, would be to place a clock on Earth and the other on Jupiter and take note of how fast they tick.
“The clock on Jupiter,” said deGrasse Tyson, “will tick slower because Jupiter’s gravitational field slows down the ticking of the clock.”
The change is so small, however, that if you had a hypothetical 100 years to live, going to Jupiter would only increase your lifespan by about 10 minutes — an addition that seems hardly worth the trip.
Watch the video, embedded below via Star Talk Radio: