Comment on If a vehicle were traveling through space at/near the speed of light, then what would happen if it turned its headlights on?

BeansPurkeypile@lemmy.world ⁨1⁩ ⁨year⁩ ago

• Prking@lemmy.world ⁨1⁩ ⁨year⁩ ago

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

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  • Zippy@lemmy.world ⁨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.

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    • GARlactic@lemm.ee ⁨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.

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      • Zippy@lemmy.world ⁨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.

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