Phase-coherent lasers are crucial for many precision tasks, including timekeeping. Here on Earth the most stable optical oscillators are used in e.g. atomic clocks and many ultra-precise scientific measurements, such as gravitational wave detection. Since these optical oscillators use cryogenic silicon cavities, it’s completely logical to take this principle and build a cryogenic silicon cavity […]
Assuming you’re not stuck in a prison cell without windows, you could feasibly keep track of the moon and tides by walking outside and jotting things down in your notebook. Alternatively, you could save a lot of hassle by just building this moon and tide clock from [pjdines1994] instead. The build is based on a […]