• Glowstick@lemmy.world
        link
        fedilink
        English
        arrow-up
        104
        arrow-down
        2
        ·
        4 months ago

        Actually, c is the speed of light in a vacuum, but light travels slower through a medium, like air. So lasers shot through air will actually travel slower than c.

        • Evil_Shrubbery@lemm.ee
          link
          fedilink
          English
          arrow-up
          2
          ·
          4 months ago

          Yes, ofc - but we’re talking about a weapon here, the air is implied as a medium, and the very-near-c with it.

          But a weapon that would construct some sort of structure or a tunnel between it’s position and the target would be something else indeed.

        • dev_null@lemmy.ml
          link
          fedilink
          English
          arrow-up
          1
          ·
          4 months ago

          It’s still travelling at c, it’s just bouncing around the medium’s particles on the way. It arrives later because it’s not going in a straight line.

          • qjkxbmwvz@startrek.website
            link
            fedilink
            English
            arrow-up
            4
            ·
            edit-2
            4 months ago

            I don’t think that’s a great way of thinking about it. I think you’re describing something more like scattering — or maybe absorption and stimulated or spontaneous emission — which does indeed happen, but is distinct from the index of a medium.

            If it were indeed “bouncing,” optics wouldn’t really work, as any n > 1 medium would cause the light to go every which way.

            • SirSmokeAlot@lemmy.ml
              link
              fedilink
              English
              arrow-up
              2
              ·
              4 months ago

              If you fire a laser that goes first through vacuum, then through a lens, then again in vacuum, at what speed is the light travelling on the other side?

              • qjkxbmwvz@startrek.website
                link
                fedilink
                English
                arrow-up
                1
                ·
                4 months ago

                It’s same as it was at first. The speed of light depends on the index of refraction of the medium it’s in, but doesn’t depend on its “history.”

                • SirSmokeAlot@lemmy.ml
                  link
                  fedilink
                  English
                  arrow-up
                  2
                  ·
                  4 months ago

                  I didn’t write it out, but what I was trying to get at was that if it would “slow down”, then it would be slower on the other side. The explanation that the light travels longer through a medium with the same speed would therefore make sense to me.

                  But then again, how it wouldn’t shoot out in every direction, that doesn’t make sense to me.

                  I don’t know much about light, that’s why i’m asking. And i’m sure some article or paper would have anwers for that question, I might search it on my own.

                  • qjkxbmwvz@startrek.website
                    link
                    fedilink
                    English
                    arrow-up
                    2
                    ·
                    4 months ago

                    Ah, I think I see what you mean.

                    I think the right way to think about this is as a wave, and in that respect, it’s no different from sound waves. If sound goes through the air, then through another medium, then out the other side back to air, the speed will follow the same general rules as with light. One notable differece is that speed of sound through many materials is faster than through air.

                    Note also that you’ll get acoustic reflections at interfaces, which is analogous to optical (Fresnel) reflections at interfaces (e.g., reflection off of glass or water).

    • Lad@reddthat.com
      link
      fedilink
      English
      arrow-up
      18
      arrow-down
      1
      ·
      4 months ago

      Imagine if they made it fire so slow that you could just do a dark souls dodge roll to avoid it

    • Jumuta@sh.itjust.works
      link
      fedilink
      English
      arrow-up
      7
      arrow-down
      1
      ·
      edit-2
      4 months ago

      just shine a laser through a thing of zircon (n=index of refraction=1.923~2)

      so speed of the laser in the zircon = c/n ~c/2