A group of Japanese scientists from the University of Tokyo has discovered that time passes four nanoseconds faster on the observatory deck of Tokyo Skytree than at ground level. The tower's deck is 450 meters (1,480ft) high. (Original article published on nature
The experiment was conducted in non-laboratory conditions using an optical lattice clock with a time loss of one second every 16 billion years.
This study is said to support Einstein's theory of general relativity, and can be implemented to read slight movements of the ground caused by earthquakes and volcanic actions, by reading the time difference every centimeter.
Professor Katori commented on Kyodo News
that they have come one step closer to field applications.
Takamoto, M., Ushijima, I., Ohmae, N. et al. Test of general relativity by a pair of transportable optical lattice clocks. Nat. Photonics (2020). https://doi.org/10.1038/s41566-020-0619-8