- #1
mach990
- 5
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Hi, I'm new to these forums. I just had a question about the Doppler effect on light (red and blue shifts of light). I've read how it is supposed to work, but I also read in a book that the speed of light is constant in all moving frames.
So if you've got a galaxy moving towards you, and it's throwing out photons towards you, all of which traveling at c, shouldn't there be no doppler effect because relative to one another, they're all traveling 186,000 miles a second, and would all reach you at the same time anyways? The analogy in the book (I think it was Hyperspace by Michio Kaku) said something about cars traveling at 99% the speed of light, and a train traveling at the speed of light, but to the car it would seem the train is still speeding ahead at 100% the speed of light, and not 1% the speed of light...
OR is it simply that if they're both going the speed of light, the effect can apply?
Bear with me, I am probably missing something obvious or just plain not understanding
Thanks for any replies. (And I hope this was the right category to put this in!)
So if you've got a galaxy moving towards you, and it's throwing out photons towards you, all of which traveling at c, shouldn't there be no doppler effect because relative to one another, they're all traveling 186,000 miles a second, and would all reach you at the same time anyways? The analogy in the book (I think it was Hyperspace by Michio Kaku) said something about cars traveling at 99% the speed of light, and a train traveling at the speed of light, but to the car it would seem the train is still speeding ahead at 100% the speed of light, and not 1% the speed of light...
OR is it simply that if they're both going the speed of light, the effect can apply?
Bear with me, I am probably missing something obvious or just plain not understanding
Thanks for any replies. (And I hope this was the right category to put this in!)