High Speed Video of Pistols Underwater - Smarter Every Day 19
Hey, it's me Destin. Welcome to this week in Smarter Every Day. Today, we're gonna try to figure something out that I've always wondered. What happens when you shoot a pistol underwater? I think revolvers are gonna act a little different than semi-automatic pistols.
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Alright, here we are in the field; this is the setup. So what we have here is a revolver in an aquarium that we made out of plate glass and silicone. This should be pretty cool, but we're gonna film this with this Phantom v10 camera made by Vision Research. We're gonna film it at 2200 frames per second. We've got about a 40 microsecond exposure time. But in order to get enough light, we have to use this, which is a 15 million candle power spotlight. This should be pretty cool, but the intent here is we're gonna fill this up with water over the pistol, and we're gonna see if we can capture that gas bubble as it comes between the revolver and the barrel. It should expand, and hopefully not blow up. But I'm expecting this to blow up. And immediately after we capture all that video, we're gonna compress it into a pretty small format and then we're gonna beam it via this satellite dish straight to the 80s so that my granddad can… I'm just kidding. Anyway, let's do the shot.
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Do I look as sad as I feel? [laugh] Or maybe nervous? I really don't want this to blow up because I don't have money to buy it again if it does, so… I'm doing this so you can learn. You don't have to blow your pistol up.
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Alright, let's see if she lived. I really hope so. 3…2…1… [bang] Yay Ruger.
Alright, so now let's talk about the results. To my knowledge, this is the first time handguns have been studied like this, and there's obviously a lot of stuff to learn here, but I'll focus on three things that are pretty simple. The first thing is, it was pretty clear that as soon as the hammer struck the firing pin which hit the primer, there was an outgassing; you could actually see a bubble. It's pretty interesting. My assumption is that that's the seal around the primer breaking down and causing a little outgassing. Nothing really new there.
The second thing that we learned is it appears that the semi-automatic pistol is more efficient at applying the gases generated by the cartridge to the back of the bullet, creating more velocity than the revolver. You noticed when the revolver fired, there was this large blast wave that came out from between the revolver cylinder and the barrel. All that is wasted energy that could be applied to increasing the velocity of the round, which wasn't. So that was also pretty interesting.
The next thing that we learned is when the weapon is fired, you see this large blast wave come out the front of the weapon. Now the assumption is, or at least the assumption I made to begin with, is that it's a spherical blast wave. It's actually not. It's more like a bagel or doughnut. It's what's called a toroidal vortex. Root word being torus. So if you were to take this and… let me draw this… alright. So this is kinda what's happening here. The gases are coming out from the barrel, and they're going in a loop around the outside of the bullet. Toroidal vortex, that's what's going on there.
Anyway, there's a whole lot to learn here. I hope you're getting Smarter Every Day. Have a good one.
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[Captions by Andrew Jackson] captionsbyandrew.wordpress.com Captioning in different languages welcome. Please contact Destin if you can help.