Friday, September 22, 2017

Cool Stuff

Screen capture from the video.
I'm exhausted, it's been a long, long week, so...

Yup, you get a video.

The scene in Saving Private Ryan where the troops go over the side of a landing craft into water over their heads is incredible. Watching them struggle with their equipment, some succeeding, some drowning before even getting ashore is harrowing.

The scene works just as it is, but of course Hollywood has to juice it up. They can't resist it. When the German machine gun rounds start ripping through the water and killing men, well, I had to throw the challenge flag.

Mythbusters had an episode where they showed what happened when even high powered rounds hit the water. They don't go far, when they're going from air to water they even break up. Yes, even the full metal jacketed rounds. (Great movie by the way. The Nuke got a lot of odd looks in high school when asked what her favorite movie was. "Full Metal Jacket! Get some!")

Ya know, there's a reason highway departments use safety barriers filled with water. Water is virtually incompressible and will absorb a lot of energy. Have you ever belly flopped into a pool? Hurts, doesn't it?

At any rate, I ran across this video by a guy who is wicked smart (own it, say it like you're from Boston), Destin does a lot of cool stuff on his YouTube channel SmarterEveryDay and this isn't the first of his videos I've watched. (I think I posted one of his videos before, I just don't remember when and quite honestly I'm too tired to look it up right now.)

This video is great, shooting a rifle underwater and filming the results with high speed cameras (I love high speed camera work). He also explains some of the science behind it. (Don't worry, you won't have to do any math, unless you really want to...)

Enjoy!



Wicked cool!



26 comments:

  1. Fun thing about (or is it pronounced 'aboot' for ya New Englanders?) that "Mythbusters" episode is that it showed musket balls to be deadly for a few feet in the water. .50cal? Not so much at all. Great example of Force Force equals mass times acceleration) vs Energy (E=M(C squared))

    There are 'slow' boxers and other fighters out there that when they make contact, it rocks the world in total pain, vs the fast, scorpion type fighters.

    My last teacher said, "Even if you lost the fight technically, if you hit them hard enough to bruise their soul, then you've won."

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    1. Hahaha! No "aboot" is more of a Canadian (the Anglophone part) thing. Also the UP of Michigan. Now in far northern New England you;ll hear a lot of French.

      Yeah, a lead ball has a lot of mass.

      "Bruise their soul!" And hear the lamentations of their women...

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    2. Especially if you accidentally bruise them anywhere 'down there.'

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  2. The water column in the barrel adds to the bullet weight. That usually results in stuck cases or bulged barrels.

    Shooting into water is a bit different. I did a lot of experimentation as a kid. Remember the beginning of Secondhand Lions? I knew I'd like that movie when I saw that!

    I could never fish successfully, so I figured shooting fish would be more fun. AND IT IS!!!!!

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    1. True, with water in the barrel the propellant has to do more work.

      Shooting fish? Interesting. As I'm not a big fish guy I never thought of that. As long as you account for refraction...

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    2. Heh. I don't have any handy literary anecdotes about the actual shooting of fish, but Ernst Jünger (in Storm of Steel) talks of hand-grenading for pike... Is that easier or harder than shooting fish in a barrel, I wonder?

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    3. Heh. I've seen that before. Nobody's actually sure what that is? The "silence.... Action!" voiceover and the empty, bouncing cans of radioactive waste (!!) make it feel like a movie stunt. (Also that nothing appears to be shrapnelled, and that what appears to be the smashed-flat body of the inert stunt grenade comes flying up out of the water towards the camera).

      But no, don't do that. Or at least, you know, throw the grenade. Or don't fish with grenades in the first place, because it's silly and you lose 80% of the catch (most concussed-to-death fish just sink).

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    4. Also... this exists, so.

      (Warning: contains questionable music and actual killing of tasty fishies, if anyone's squeamish about that sorta thing.)

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    5. a bear:

      Part of the starboard aft pontoon is deflated. Don't think this was a simple movie stunt. Shrapnel would stay underwater. Most of the damage from underwater blasts is the water itself. Worst place to be around an underwater explosion (besides at the direct site of the explosion) is above the boom point. Water doesn't compress easily, so it goes up (reason it is good to get your depth charges under the enemy sub, or why the US spent so much time and money trying to get their early WWII torpedoes to work to blow up magnetically under a ship's spine.)

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  3. I don't think we could fire the Navy's railgun underwater because of that annoying water and electricity thing, but a railgun projectile hitting the water could probably be modeled by someone with way better math skills than mine.

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    1. Water? Electricity? What could possibly go wrong?

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  4. The Slo Mo Guys have some fun stuff up on their channel, too.

    Wasn't there also a bullets-in-water scene in Gallipoli?

    Watching the pulsing bubble reminded me of some ASW training, that at depth the bubble from torpedoes, depth charges and mines actually moves towards the sub as it pulses. Something to do with relative densities or something.

    /
    L.J.

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    1. Yeah, I plan on checking out the Slo Mo Guys this weekend.

      I need to re-watch that film, but I do recall that there may have been a bullets underwater scene.

      Um, ASW, me likee.

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  5. Interesting video Sarge, going to check out his channel. OBTW....The Nuke sounds a little like Eve from the show Last Man Standing.....hehe.

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    1. Unfortunately I only saw a couple of episodes of that show and only for a couple of minutes at a time. Now I need to watch some episodes to do an Eve/The Nuke comparison.

      I've heard good things about the show but I hardly watch TV at all these days, just can't abide the commercials.

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  6. First season there is a lot of shouting instead of just talking to each other, many shows do that I've noticed. Second season better than the first. I was a Tim Allen fan from Home Improvement and his LMS character is much the same from that first series. His LMS character doesn't side with the Democrats.

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    1. I'm familiar with the show, especially since it was cancelled. I too enjoy Tim Allen's work.

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  7. I've watched several of Destin's Smarter Every Day vids. My favorite was his two part vid testing the theory that water drains backwards in the Southern Hemisphere. His vid on formation flying was well done also.

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    1. I just finished watching the one on formation flying. Nice!

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  8. On D-Day the German gunners were shooting MG-42s using 7.92mm long brass ammo. Twice the power of the AK round and with a considerably higher muzzle velocity. The rounds entered the water at a very oblique angle that would lessen the drag on the bullet. I would say that it was very plausible that many casualties were inflicted on the troops in that manner. Big difference between shooting a weapon underwater and from above at an angle. Would like to see this guy get an MG42 and do this test for theory confirmation. Just my $.02 worth......

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    1. Mythbusters had a segment where they were firing into a pool, trying to replicate what you mention. The bullets tended to break up on impact, including full metal jacketed rounds fired from a 50 cal. I'll have to dig that up. Another point to consider is why bother shooting at guys who are probably going to drown anyway and who are, at best, combat ineffective until they get onto the beach. Most gunners were going for the guys in the landing craft or coming ashore.

      I'll try and find that video. A bullet will penetrate water, but not very far.

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  9. Mythbusters aside, I would prefer to see some more relevant evidence concerning projectile ballistics of a more recent nature. The MBs boys had a bad habit of exaggeration to enhance their reps. You know how ratings are more important than actual facts. Acquire an MG42 and perform a real ballistic hydraulic experiment in a calibrated setting. I have fired a '42 and know that it is a very formidable device. The troops that went ashore on 6/6/44 faced a veritable wall of high velocity lead above and/or below the waterline. The "Zipper" was not a weapon to be taken lightly as they were soon to realize.

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