• niktemadur@lemmy.worldOP
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    30 days ago

    So I might perceive a stream of photons as radio waves from our current inertial frame, but if I were on a ship approaching the speed of light head-on towards that same stream of photons, I might perceive them as visible light? Or ultraviolet or gamma ray.

    Wait… that doesn’t sound right, for some reason.
    It took billions of years of universe-stretching for the CMB to redshift to microwave, I don’t think me pushing pedal to the metal for a few seconds on a rocket ship is going to counteract all those years.

    Then also those CMB photons are more diffuse, spread out.
    Doesn’t Coloumb play into this?

    • AbouBenAdhem@lemmy.world
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      30 days ago

      It took billions of years of universe-stretching for the CMB to redshift to microwave, I don’t think me pushing pedal to the metal for a few seconds on a rocket ship is going to counteract all those years.

      We do see shifts in the CMBR due to local velocity changes though—for instance, we can tell that the sun is moving at about 370 km/s relative to the CMBR frame due to its radial movement through the galaxy and the motion of the galaxy itself through space.

      • niktemadur@lemmy.worldOP
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        30 days ago

        Sure, that I do get, it’s just that I’m guessing my local movement at the speed of light for a moment can blueshift a radiowave or microwave photon only a fraction of what is needed to get it into the visible light spectrum, surely never all the way to ultraviolet or gamma rays.