Spacecraft data has confirmed successful deployment of the futuristic technology.
  • @[email protected]English
    11•3 months ago

    If photon hitting a surface can impart momentum, does generating photons also impart momentum? Like, if you put a solar powered laser pointer in space, would it move?

    • @[email protected]English
      19•3 months ago

      Yes, it’s called radiation pressure by emmision

      The formula for it is Irradiance^1 of the emission/speed of light.

      1: irradiance is basically how much power per unit area is emmited by the object, it’s units are watt/m^2

      As for the lasers thing, I’m not a 100% sure how effective that will be and TBH lasers are pretty complicated and I don’t really get them

    • @[email protected]English
      10•3 months ago

      Yes, but that would be a lot less efficient. With a dielectric mirror you can get easily 99.9% of the maximum momentum gain from the light, while with a solar powered laser you would get for the emission the compounded efficiency of the solar panel + storage + laser, so way below 10%. So you would gain around 10 times more impulse from your solar panel absorbing light than from the actual laser.

      The final momentum gain is a bit different as the maximum you can gain from a photon is double its momentum (because you can reflect it back with opposite direction).

    • @[email protected]English
      7•3 months ago

      Sure, but it would be less efficient than a sail, and since the incoming radiation would impart inertia on the solar panels, you would still be limited on where you could steer.

      • @[email protected]English
        2•3 months ago

        Sail absorbs power while also acting as a sail, and you can use the lasers to steer?

        It would also be like steering a boat more or less no?

        • @[email protected]English
          1•3 months ago

          The solar sail reflects light instead of absorbing it so you get to double dip on photon momentum.

          And sure, you can steer with the laser I suppose, but with that kind of super weak deltaV, you’re not going to be exactly doing donuts in the solar system.

          Even the massive solar sail only imparts a super small amount of force. It’s only useful because it does so for free over a long period of time with no air resistance.

          You’d be better off using a conventional thruster to do whatever steering you needed to do before letting the sail take over. It’s not like you need to steer around any obstacles.

    • @[email protected]English
      7•3 months ago

      aww so people are pushed away from me because of my brightness and not because I’m dumb??