The Physics of the Railgun

http://www.wired.com/2014/08/the-physics-of-the-railgun/

by oceanstone • 12 years ago

27 5 12 years ago

daveslash• 12 years ago

It would not surprise me if, given time, we see smaller versions of these being produced for individuals. Given the controversy over gun-control (what exactly defines a gun?), I wonder how this will play out. In this comment, I take no side in the gun-control discussion; I'm curious how the national discussion will change.

Edit: This is in the context of U.S. gun control discussion.

trhway• 12 years ago

airguns can be pretty powerful too. In Russia, for example, the law limits the muzzle velocity and kinetic energy of projectile. The laser guns is different issue though :) And there is also various nonlethal weaponry like 96GHz directed energy devices (http://en.wikipedia.org/wiki/Active_Denial_System) which i suppose will get to be miniaturized soon.

frenchman_in_ny• 12 years ago

As a purely technical matter, it's defined as the receiver (or lower receiver, as the case may be)

gusgordon• 12 years ago

I think that smaller (portable) versions are currently almost impossible to make. Square-cube law is a big factor here, and there would be a ton of inaccuracy. Maybe if it was done very well. Coil guns are more feasible and can probably be much more efficient, so more powerful, at smaller scales.

madaxe_again• 12 years ago

Railguns are fun to build as a hobby project. All you need are a pair of rails, and a conductive slug. Ball bearings work well.

The tricky bit is reducing arcing between the rails and the slug, as you can end up with it either welding onto the rails, or carbonising and ending up with "dead patches", sapping your power. Main trick was to go for gobs of current with as low a voltage as we could manage.

We used big capacitors re-purposed from a tesla coil (cider jars!), and copper plumbing pipe filled with gravity-fed circulating mineral oil to keep the temperature manageable.

Think it was 1.5m long or so, and we were using a 10mm ball bearing... and it happily disappeared deep into a brick wall never to be seen again.

Fun times, but lethal if you're not careful.

The Physics of the Railgun

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