Understanding Earth’s rotation in space is crucial for GPS navigation, and now we have an extremely precise way to measure it with lasers and supermirrors
Source:
https://www.newscientist.com/article/2249144-huge-underground-lasers-measure-earths-spin-with-extreme-precision/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home