One of the incredible things about astronomy is how much we can tell about stars that we can never, ever approach. But we can take the temperature of a star with our eyes, thanks to the Doppler effect.
We know the Doppler Effect as the reason why horns and sirens drop in tone as they rush by us. But the Doppler Effect works on objects that are twisting around, too. We'll tell you how the Doppler Effect gets in a tangle.
The Doppler Effect is physics that is so ingrained in our brain that even the movies get it right. Any time some character is walking down a street and a car or train rushes past, the sound of the horn drops down a few notes as it passes by. Anything else would be jarring. We all hear it, all the time. But how was it…
This truly awesome video has the answers to that question. It imagines a trip down a desert highway at speeds approaching light, and then shows all the weird and wonderful optical effects the theory of special relativity says we'd experience.
The Doppler Effect is the reason why car horns drop in tone as they go by, and radar speedometers work. But a new material may actually create an inverse Doppler Effect.