A group of researchers from Japan discovered that time moves faster at the top of towers and skyscrapers than on the ground. In a new study, the researchers explained the effects of gravity on time. The study was led by Hidetoshi Katori, a quantum electronics professor at the University of Tokyo. It was published in the journal Nature Photonics.
Experimenting on a skyscraper
For the study, Katori and his team visited the Tokyo Skytree, a broadcasting and observation tower in Sumida, Tokyo. Standing at the height of 2,080 feet tall, the Tokyo Skytree is currently known as the tallest tower in the world.
As part of the experiment, the researchers went to the top of the tower and installed an optical clock the size of a refrigerator. This device is capable of providing accurate readings of time. The purpose of the experiment is to compare the readings of the clock to those of another device mounted on the ground.
Findings of the study
After carrying out the study, the researchers learned that the time measured at the top of the tower moved faster than on the ground by four nanoseconds. One nanosecond is equivalent to one-billionth of a second. The concept of the study is similar to the previous findings of scientists regarding satellites operating at low-Earth orbit. According to the scientists, the time in these satellites moves faster than on the ground.
Although the idea regarding the difference in time has been documented in satellites, the study carried out by Katori and his team is the first one to present a more Earth-based application. Specifically, their study is the first to use skyscrapers.
Effect of gravity on time
The findings by Katori and his team prove the theory presented by Albert Einstein, which states that the movement of time is affected by the strength of gravity. Since gravity is weaker at higher altitudes, time tends to move much faster.
"People use clocks to tell the time, but they will become an apparatus to measure time and space, such as the difference in altitude, in line with the theory of relativity," Katori said according to Japanese media outlet The Asahi Shimbun.