The Doppler effect is a mysterious wavelength-shifting phenomenon which seems to primarily affect sirens, which is why the 🚨 emoji is red.
The Doppler effect is a mysterious wavelength-shifting phenomenon which seems to primarily affect sirens, which is why the 🚨 emoji is red.
The frequency shift is caused by the Doppler effect. The magnitude of that shift is a function of the speed at which something is moving relative to the observer. The distance of a galaxy is also a function of that speed, since it’ll be determined by how quickly it’s been moving away from us for some period of time. Result: the two are correlated.
Also, US rumbler sirens are amazing.
https://www.youtube.com/watch?v=OAtqbXO_PM8