Comment on Uh oh lol

Kolanaki@pawb.social ⁨1⁩ ⁨day⁩ ago

• Agent641@lemmy.world ⁨1⁩ ⁨day⁩ ago

  Blue shift, it’s moving towards you, the photons are being “compressed” to a higher, bluer frequency. Redshift, the light is being “stretched” to a lower, redder frequency.

  Something ominous about the post is that a cosmic object that is moving towards you at a steady rate is consided “blueshifted” in the past tense, it’s velocity is steady. If a galaxy is “Blueshifting” in the present tense, then that galzy is somehow accelerating at you, which is impossible unless it’s under direct control by an entity, presumably a kardeshev level 3 civilization.

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  • Kolanaki@pawb.social ⁨1⁩ ⁨day⁩ ago

    Isn’t the rate of expansion in the universe increasing, and at an uneven rate at that?

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    • deltapi@lemmy.world ⁨1⁩ ⁨day⁩ ago

      The expansion is supposed to be happening everywhere at the same time, not just at the edges.
      For example, tomorrow there should be more space between the Sol and Alpha Centauri systems than there was yesterday.
      Our present understanding suggests that ‘normal’ universal expansion should not (in and of itself) result in anything moving towards us.

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      • Kolanaki@pawb.social ⁨1⁩ ⁨day⁩ ago

        Aren’t the milky way and andromeda on a collision course with each other?

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      • Davel23@fedia.io ⁨1⁩ ⁨day⁩ ago

        For example, tomorrow there should be more space between the Sol and Alpha Centauri systems than there was yesterday.

        Galaxies are gravitationally bound, they do not expand in the same way as the universe.

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    • ProfessorPeregrine@reddthat.com ⁨1⁩ ⁨day⁩ ago

      Expansion red-shifts light.

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• Bane_Killgrind@lemmy.dbzer0.com ⁨23⁩ ⁨hours⁩ ago

  Yes which would be very odd for a far away object

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• tetris11@feddit.uk ⁨1⁩ ⁨day⁩ ago

  No, it’s just depressed and that makes us feel sad and worried for it.

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  • Kolanaki@pawb.social ⁨1⁩ ⁨day⁩ ago

    I’m blue shifting-daba-dee-di

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• Sterile_Technique@lemmy.world ⁨1⁩ ⁨day⁩ ago

  It’s the doppler effect, but with light instead of sound, and for the same reason.

  Thing emits sound/light waves at a constant rate: sound/light waves hit you at a constant rate.

  Thing continues to emit the same sound/light at the same rate, but starts to move toward you: sound/light waves hit you at a faster rate, causing the sound/light to turn higher-pitched/bluer.

  Thing continues to emit the same sound/light at the same rate, but starts to move away from you: sound/light waves hit you at a slower rate, causing the sound/light to turn lower-pitched/redder.

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