4 ms·

You just turn around at the half way point

• notfed 3y ago
  At which point shielding gets even more complicated.
  • timschmidt 3y ago
    Less complicated. The rocket exhaust literally forms a plasma shield in front of the decelerating rocket.
    • cooper_ganglia 3y ago
      Well then, it's easy: Just always face the exhaust in that direction! It's not rocket science!
      • JumpCrisscross 3y ago
        > always face the exhaust in that direction! It's not rocket science! You don't see a problem with trying to accelerate with two exhaust streams at 180º to each other?
        • ithkuil 3y ago
          What if the front one is only a small fraction of the thrust at the rear? Would that be enough to "clear the path". Surely it would cost some efficiency but it may beat he alternative
          • deleted 3y ago
            [deleted]
          • timschmidt 3y ago
            Whipple shields [1] don't weigh much, and don't involve negative acceleration of any kind. 1: https://en.wikipedia.org/wiki/Whipple_shield https://en.wikipedia.org/wiki/Whipple_shield
          • the_third_wave 3y ago
            In other words the space-equivalent of a supercavitating torpedo like the Shkval [1], more or less an underwater rocket which creates its own gas bubble around the projectile by deflecting part of the exhaust stream to nozzles on the front of the device. [1] https://en.wikipedia.org/wiki/VA-111_Shkval https://en.wikipedia.org/wiki/VA-111_Shkval
        • cooper_ganglia 3y ago
          In a universe where every action has an equal and opposite reaction, why not make those reactions argue about it?
    • senectus1 3y ago
      what about for the period of time that you're travelling sideways with a largely unshielded broadside facing not exactly empty space?
      • eru 3y ago
        You wouldn't literally turn around. You'd probably move your rocket engine over to the other side (or have both a front and back engine in the first place). Most of the mass of your spaceship will be fuel (like 90%+). You can use that as shielding.
  • PeterisP 3y ago
    This is already an unrealistic thought experiment, since continuous 1g acceleration for 20 years is so ridiculous that it requires a magic engine (i.e. consuming most of the ship mass in a matter-antimatter reaction) so if we're at it, we can also assume magic shielding which will also shield the crew from all that antimatter and its annihilation. It's not a coincidence that the original post relativistic spaceship doesn't even bother considering larger accelerations than 0.1g, since achieving even that is a wild assumption.
• thatwasunusual 3y ago
  Still needs to slow down before turning around. ;)