• noodles@sh.itjust.works
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    2 months ago

    OK I need someone to explain this to me cause AFAIK light speed is constant no matter how fast moving the source is

    • captainlezbian@lemmy.world
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      2 months ago

      So light is a wave. Shorter wavelengths are bluer longer wavelengths are redder. When you walk towards a wave you hit the peaks and troughs faster than had you been still. They come slower if you’re walking away from it. The Doppler effect is that but with light waves and velocities that make it relevant

      • BB84@mander.xyzOP
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        2 months ago

        While it is true that space time dilation can cause red/blueshift, that is a distinct from the doppler effect which is the primary effect here.

        (dilation plays only a small role: without time dilation our answer going from 700nm to 350nm would be 0.5c instead of the 0.6c calculated below)