Einstein's theory of general relativity upended humanity's understanding of the universe more than a century ago, and since then, scientists have discovered that the steady march of time is anything but steady. Among the haunting implications of general relativity is that time passes more quickly at the top of every staircase in the world than it does at the bottom.
This mind-bending phenomenon happens because the closer an object is to Earth, the stronger the impacts of gravity are. And because general relativity describes gravity as the warping of space and time, time itself travels more slowly at higher altitudes and greater distances from Earth, where gravity has less of an effect.
So, if time is linked to gravity, does that mean that people on top of mountains age faster than people at sea level do? Does increased gravity actually make people age more slowly?
Indeed, for all objects farther away from a gravitational field, such as Earth, time actually moves more slowly, James Chin-wen Chou, a physicist at the National Institute of Standards and Technology (NIST) in Boulder, Colorado, told Live Science in an email. That means people who live at high altitudes age a tad faster than those plodding through space-time at sea level.
"Gravity makes us age slower, in a relative term," Chou said. "Compared to someone not near any massive object, we are aging more slowly by a very tiny amount. In fact, for that someone, the whole world around us evolves more slowly under the effect of gravity."
Related: What is the shape of the universe?
The differences are minor but measurable. If you were to sit at the peak of Mount Everest — which is 29,000 feet (8,848 meters) above sea level — for 30 years, you would be 0.91 millisecond older than if you had spent those same 30 years at sea level, according to NIST. Similarly, if twins living at sea level were to part ways for 30 years, with one relocating to mile-high (1,600 m) Boulder, Colorado, and the other staying put, the high-elevation twin would be 0.17 millisecond older than their twin when they reunited.
In a striking experiment, NIST researchers used one of the most precise atomic clocks in the world to demonstrate that time runs faster even a mere 0.008 inch (0.2 millimeter) above the Earth's surface.
"These aren't just calculations," said Tobias Bothwell, a physicist at NIST and co-author of a 2022 paper published in the journal Nature describing the experiment. "We have seen the change in the ticking of a clock at a distance roughly the width of a human hair," he told Live Science.
The key to understanding why massive objects warp the passage of time is recognizing that "space-time" is a four-dimensional tapestry woven from three space coordinates (up/down, right/left and forward/back) and one time coordinate (past/future). Gravity, in a relativistic model, is what we call it when any object with mass distorts that tapestry, curving space and time as one.
"Anything that possesses mass affects space-time," Andrew Norton, a professor of astrophysics at The Open University in the U.K., told Live Science in an email. In the vicinity of an object with mass, "space-time is distorted, resulting in the bending of space and the dilation of time.
"The effect is real and measurable but negligible in everyday situations," Norton said.
When it comes to non-everyday situations, however, this phenomenon — also known as gravitational time dilation — can get messy. According to Norton, GPS satellites circling the globe at an altitude of 12,544 miles (20,186 kilometers) need to adjust for the fact that their clocks run 45.7 microseconds faster than clocks down here, over the course of 24 hours.
"The most pressing effect of relativity over the passage of time is probably the accuracy of GPS," Chou said. "Because they [GPS satellites] are moving at high speeds and high up away from the earth, the relativistic effects from speed and gravity need to be carefully accounted for so that we are able to infer our position on the globe with high accuracy."
Closer to home, it is clear that gravity does, in fact, make us age more slowly. Sure, it's usually only a matter of milliseconds, and cowering at sea level is hardly a viable anti-aging strategy. But time is both precious and fleeting, especially when distant from any objects with mass.
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.
Joshua A. Krisch is a freelance science writer. He is particularly interested in biology and biomedical sciences, but he has covered technology, environmental issues, space, mathematics, and health policy, and he is interested in anything that could plausibly be defined as science. Joshua studied biology at Yeshiva University, and later completed graduate work in health sciences at Cornell University and science journalism at New York University.
Nice article. Aging fast or slower should be assessed based not only on passage of time, but in the environmental conditions too. Living on top of the Himalaya Mountains peak would instantly kill me because there is near zero breathing oxygen and temperatures of well below freezing. The less than one millisecond difference according to Einstein prediction worth in theory only.Reply
"Indeed, for all objects farther away from a gravitational field, such as Earth, time actually moves more slowly."Reply
All of our clocks use oscillation for our clock tickers. All oscillations change frequency with linear or angular accelerations, or a gravity gradient. We use oscillations to measure displacement, orientation and gravity. With 3 axis oscillations. Like In your smart phone. A MEMS device. An oscillation will change with elevation too. We use oscillation to map gravity on the surface of the earth. Science calls this a space-time change. Our atomic clocks use oscillations.Reply
Lets place a rotating shaft in the vertical position. Now, we have the same time at both ends. At any orientation. Space-time seems to have disappeared.
They also say that it is impossible to synchronize two clocks, and therefore we can not measure one way path of light. But a rotating shaft can synchronize any two clocks......or act as a clock itself.
Therefore time is really omnipresent. We just need rotational clocks tickers to measure it. Instead of oscillation.
The change of position on one end of shaft on earth, happens at the same time as the change of position of the other end on the moon. So, a rotating shaft has an instant transfer of power and information at any distance. An instant transfer action.
Classical science is the only true science. But it is no longer taught in our schools.