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> I expect them to use needles fired precisely by a mini railgun at exposed areas of skin. How in the world could a railgun compete with chemical explosives?

> I expect them to use needles fired precisely by a mini railgun at exposed areas of skin. How in the world could a railgun compete with chemical explosives? The energy density of batteries is nowhere even close to the energy density of chemical explosives; throw away the sci-fi railgun thing and put a small EFP on the UAV instead. That would be a thousand times more lethal with a fraction of the weight. If you really want to use poison needles, then turn the UAV into a pincushion and crash it into people. If you're dead set on throwing needles, give it a compressed air blowgun. Small scale railguns make no sense.

what-imright 4y ago
>>How in the world could a railgun compete with chemical explosives? It can selectively kill in a crowd. And no recoil, better accuracy during rapid fire. Compressed air requires a canister of fluid that requires weight. With a rail gun, much of the weight is in the needles, which could be very thin indeed. When it's out of ammunition, it can do the suicide run perhaps. But the key is the unit doesn't need to carry all the energy required to dispense the projectiles on launch. Can feed off solar or power lines half way through its lot and therefore extend range or needle load. In fact if you had a rechargeable system the drone could conceivably, albeit slowly, travel halfway around the globe, assuming it can extend its solar panels and float on the ocean. I also expect they'll be totally silent and made of transparent material.
- kaashif 4y ago
  > And no recoil, better accuracy during rapid fire. Good troll so far, but I think this puts it over the top.
- MichaelCollins 4y ago
  As kaashif points out, railguns have recoil. Recoil isn't a special trait of chemical propellants, it's Newtonian. The railgun pushes the needle, so the needle pushes the railgun. Add to that, the rails and the capacitor bank have mass, substantially more mass than the needles. The same force that sends a railgun projectile down the rails also tries to push the rails apart. The rails need to be strong enough to resist this force trying to separate them. You can't even let the rails flex, because if the rail loses electrical contact with the projectile then there's no current flow and therefore no force to push the projectile. For a railgun this small you can probably wrap the whole assembly in carbon fiber and call it a day, but there's no way any of this comes out weighing less than the needles themselves. Just one of the capacitors will weigh more than a bunch of needles. An air canister weighs to much? A standard CO2 cartridge weighs about 50-100 grams and has ample capacity. A CO2 cartridge in an air pistol lasts for dozens of shots, that's plenty. And silent and transparent? Now I think you might be trolling. Neither UAVs nor railguns are silent and only a few components in them could conceivably be made transparent.

what-imright 4y ago

>>How in the world could a railgun compete with chemical explosives? It can selectively kill in a crowd. And no recoil, better accuracy during rapid fire. Compressed air requires a canister of fluid that requires weight. With a rail gun, much of the weight is in the needles, which could be very thin indeed. When it's out of ammunition, it can do the suicide run perhaps. But the key is the unit doesn't need to carry all the energy required to dispense the projectiles on launch. Can feed off solar or power lines half way through its lot and therefore extend range or needle load. In fact if you had a rechargeable system the drone could conceivably, albeit slowly, travel halfway around the globe, assuming it can extend its solar panels and float on the ocean. I also expect they'll be totally silent and made of transparent material.

kaashif 4y ago
> And no recoil, better accuracy during rapid fire. Good troll so far, but I think this puts it over the top.
MichaelCollins 4y ago
As kaashif points out, railguns have recoil. Recoil isn't a special trait of chemical propellants, it's Newtonian. The railgun pushes the needle, so the needle pushes the railgun. Add to that, the rails and the capacitor bank have mass, substantially more mass than the needles. The same force that sends a railgun projectile down the rails also tries to push the rails apart. The rails need to be strong enough to resist this force trying to separate them. You can't even let the rails flex, because if the rail loses electrical contact with the projectile then there's no current flow and therefore no force to push the projectile. For a railgun this small you can probably wrap the whole assembly in carbon fiber and call it a day, but there's no way any of this comes out weighing less than the needles themselves. Just one of the capacitors will weigh more than a bunch of needles. An air canister weighs to much? A standard CO2 cartridge weighs about 50-100 grams and has ample capacity. A CO2 cartridge in an air pistol lasts for dozens of shots, that's plenty. And silent and transparent? Now I think you might be trolling. Neither UAVs nor railguns are silent and only a few components in them could conceivably be made transparent.