astronomy

Tag archives for astronomy

What’s the application? An optical frequency comb is a short-duration pulsed laser whose output can be viewed as a regularly spaced series of different frequencies. If the pulses are short enough, this can span the entire visible spectrum, giving a “comb” of colored lines on a traditional spectrometer. This can be used for a wide…

What’s the application? Measuring the distance from the Earth to the Moon by bouncing a laser off one of the retro-reflector arrays left there by the Apollo missions. What problem(s) is it the solution to? 1) “How does the distance from the Earth to the Moon vary over time due to things like tidal drag?”…