• Phil K@lemmy.world
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    1 year ago

    Surely that depends whether you’re in the vehicle (and can see the lights) or an observer outside of the vehicle

    • Zippy@lemmy.world
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      1 year ago

      Absolutely. The wavelengths would be significantly increased or decreased depending if viewed from the outside standing standing still in respect to the spacecrafts motion.

      From inside the spacecraft it would appear normal. What would seem weird is that objects you are traveling towards would appear much closer than if you were stationary to said objects. Objects behind you would appear much farther away.

      • GARlactic
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        1 year ago

        This is a technicality, but the wavelengths wouldn’t actually change. They would be the same length from both perspectives. What actually changes between the two different observers is how long a foot/meter actually is.

        Although even that isn’t technically right either.

        • Zippy@lemmy.world
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          1 year ago

          I think you might be incorrect. To a stationary person on the ground, the light they emit would be red or blue shifted depending on the direction they are going. Red or Blue shifting is the same as saying your wave length is changing.

          What I think you meant to say is that the speed of light does not change at all. Which is correct. That has nothing to do with the wave length which can change in frequency.

          Edit. Will clarify. Only the stationary person will see the wavelength or other term, frequency change. The person in the spaceship will not notice any changes in the light they emit as it will be entirely cancelled out by the time dilation.