Maybe it’s slightly convoluted but here’s how I tackle it in my head: I just think of infrared and ultraviolet, ultraviolet being greater frequencies than violet and infrared being the opposite for red. Blue is on the way from infrared to ultraviolet, so blue has a greater frequency than red.
Comment on Doppler
Kbobabob@lemmy.world 6 days ago
For some reason I can never remember which causes red or blue shift, but with this I might actually remember it
0ops@lemm.ee 6 days ago
lena@gregtech.eu 6 days ago
Blue has a smaller wavelength, so when something is approaching fast it “squishes” the light, making a smaller wavelength.