17 thoughts on “Alien Stellar Engines

  1. Dennis Wingo

    Back when the Gamma Ray Observatory’s BATSE instrument was first producing data the until then undetected Gamma Ray Bursts caused quite a stir as they were not predicted.

    We were students and offered to the scientists the hypothesis that these were warp signatures of advanced alien races. We got a lot of chuckles for it.

  2. Edward Wright

    I don’t see how this proposed “stellar engine” would work, however. Seems the light pressure would push the mirror out of position much more rapidly than it would move the star. Am I missing something?

      1. ken anthony

        That mirror is a light sail which does overcome gravity. Any gravity, because even the slightest push changes the orbit. I believe Ed is right.

        1. jrman

          there’s more (or maybe less) to it than an orbiting object. if it was orbiting in the Keplerian sense then the thrust would be changing directions, and result in no net acceleration over one orbital period . . .

  3. Fletcher Christian

    It would be impossible to build a solid structure of that size anyway. Regarding whether it is possible to make such a structure work: Imagine a Dyson swarm with each unit (or at least a high proportion of them) having a large mirror attached to it. It would be possible to arrange that the mirrors were always pointing in one direction in the sky. This would produce a (small!) thrust from each unit, from light pressure.

    The coupling between this huge array of mirrors and the parent star would simply be gravity. As long as the thrust from the mirror is considerably lower than the gravitational force between the structure and the primary, then the system remains bound. What is needed here is the precise opposite of what is required for a lightsail ship; for one of those, one needs a light structure compared to the thrust.

  4. Fletcher Christian

    Oops. One more thing: It might be better to generate the thrust another way. Using the sunlight power collected from a Dyson swarm to produce a really big laser beam focused on one small spot on the star might well turn the star itself into a reaction engine.

    1. Edward Wright

      Deliberately causing a solar flare massive enough to move a star is medically contraindicated.

      1. Fletcher Christian

        I never said it wasn’t dangerous :) . However, how big the flare needs to be depends on the timescale on which one wants to work.

      2. Karl Hallowell

        is medically contraindicated.

        We wouldn’t be fools! That’s what cool shades are for!

Comments are closed.