I’ve heard stories from train drivers about what happens when a speeding train hits a suicidal jumper. The phrase “blows the hands and feet off” was said more than once. Hefty bags full of soup, we are.
Cite?
It is honorable to volunteer your body so that a watermelon may live.
I had read that in a book about the Napoleonic War (specifically the big naval battle), but of course this is based on the recollection of sailors, not scientists. According to the tale, the captain was “showing off” by eating an apple with every appearance of enjoying himself (keeping morale up, stiff upper lip) when a cannonball passed nearby and one of his aides collapsed.
I don’t believe the specific example is given at this source:
Which of course isn’t conclusive, given the skepticism and a lack of testing (it wouldn’t be legal, obviously!).
An article I read about the search for missing airmen in Vietnam mentioned that they could tell if the pilot died on impact or after. A jet impacting the ground at 500mph (or more) the sides of the pilot’s boots would blow out from the inertia of the blood as it mostly channeled into the feet. Intact shoes indicated he died after landing, probably by parachuting.
To consider what happens, imagine the impact moment by moment. The shell is going at supersonic speeds. it starts to push into the body, which is a meaty amalgam of fibre and water. Using either concept- the body material in front of the shell cannot get away fast enough. Water is essentially incompressible, so it is pushed out of the way. the material seeks to escape by pushing the material around it out of the way. This happens at supersonic speed, and as the shell progresses through the body, a cone-shaped pressure wave is produced. This is analogous to the blast wave from an explosive. It is essentially the same thing - a cascade material is thrown violently away from the path of the projectile. My impression would be it is mainly a conical shock wave (like a speedboat bow wave or a supersonic boom), with there also being lesser shock waves in all directions.
This is also why watermelons explode.
So- shell in, hamburger out.
An M829 shell has about 12 MJ of kinetic energy. Suppose it delivers just 1% of that to your body (slowing by just 0.5% as it passes through you). If you weigh 100 kg, then it can accelerate every piece of you to 50 m/s (about 110 mph). The pieces are not going to be going in the same direction.
I can’t help but be reminded of the discussion in this book, a memoir from a young officer (at the time) tasked with recovering and repairing knocked out tanks during the Allied campaign against Germany during WWII.
He reminds us that the Sherman tank, while adequate for winning the war, was just outmatched by the contemporary German weapons in most important ways (gun, armor). So many of them were holed by 75 mm shells, which had killed the crews, so they had to be massively cleaned up. The interiors had horribly damaged human remains spread out all over.
Sobering, sad, and at the same time, technically interesting stuff.
Sure, but part of the issue is that watermelons are essentially solid. There’s no stretch or give to them, while there is a LOT to most human tissue.
Case in point, people hit with the .223 slugs don’t burst open like a watermelon at all, unless maybe they’re hit in the head, which doesn’t have much stretch.
Anti-tank shells of that era typically had a small explosive charge inside them, as well as likely sending a whole lot of shrapnel from the armor and shell into the interior of the tank along with the shell itself, which would then blow up.
Modern ones just basically poke a hole/fragment as they penetrate, then they probably bounce around, and in the case of the depleted uranium ones, they catch fire as well.
It wasn’t solely a matter of a big fast bullet poking a hole in the tank…
And in Europe anyway, there were a LOT of tanks destroyed and/or disabled by German Panzerfaust infantry anti-tank weapons, which used shaped charges, which are a weapon where high explosive is used to force a copper or other metal slug through armor by means of clever shaping and the Munroe/Neumann effect. Essentially if you make a conical shape in a chunk of explosive, line it with copper, and detonate it from the base, the convergence of the shockwaves forms that conical copper liner into a really fast moving slug that punches through armor, and sprays out the other side. The effect is more or less independent of velocity- if anything, slower is better. This is what most anti-tank missiles, mines, rockets, etc… use to penetrate armor. In fact, if it’s not shot out of a cannon, it’s probably a shaped charge.
I don’t see how this is possible. If a round is creating such a powerful shockwave to kill without even hitting you, then it is dumping a ton of energy as it travels, which would dissipate its speed, and destroy its accuracy, over any reasonable distance.
You wouldn’t need to look at the boots, if you could find them. Assuming the remains were undisturbed, a “parachute skeleton” would look completely different (as in intact, more or less) than one that had hit the ground going hundreds of mph sitting inside a flimsy aluminum can. Now, if all you had were the boots and a couple of bones, I guess that could make sense.
I don’t know what’s correct here, but it’s not clear to me why your claim is necessarily correct. Can’t a shockwave be traveling through the air without dissipating much energy, but then dump a lot of energy into a solid object that it hits?
That’s why the watermelon explodes like it contained an explosive. Whereas the same concept would apply to humans, the only question would be how much the stretchy clingy fiber aspect of meat can contain the similar compressed-water explosion that the shell’s shock wave produces as it penetrates.
My totally amateur guess is that the skin and subcutaneous muscle layers are a bit more containing, and a significant part of the relief of the pressure wave would be via the openings created by the entry and exit of the shell - thus ripping those openings a lot farther open than initial penetration holes, and meanwhile spreading the scrambled contents out those holes. The main question is how much of the body around the through-hole is scrambled enough to disconnect from its regular bodily connections (i.e. thagomizes) and how fast and multi-directionally it goes flying out. Again, as if the body was containing an explosion, but with two open escape channels.
The shockwave would have to be constantly produced by the projectile, as it can’t travel as fast or faster than it, the projectile being supersonic and all.
So all the energy that is needed to be in the shockwave to kill you would have to be constantly be shed by the projectile.
I am not a physicist nor a hydrodynamicist, so I certainly could be wrong, but I just don’t see how such a thing could be possible.
Destin Sandlin, he of the SmarterEveryDay YouTube channel, got together with some friends recently and built an air cannon that can fire baseballs at supersonic speeds. In early tests, the baseballs were absolutely disintegrated on impact with a heavy steel backstop. Suffice it to say they carried a lot of energy.
In a later video, they tried shooting baseballs at various targets, including a gallon jug of mayonnaise. The baseball, at ~1000 MPH, is going a good bit slower than a kinetic penetrator, and it’s also larger in diameter. But even with this test, you can see that crashing one object into a target that’s basically liquid or not-much-stronger-than-liquid tends to obliterate it. Video here is cued to the start of the segment where they do the mayo test:
This cite quotes an experiment that shows a cannonball does not create a “wind of ball.”
Mythbuster video of a cannon shooting a side of pork…with a load made out of a length of chain.
Big, hard, fast things slamming into you will tear you apart.
Yup. This. Instant Gazpacho. Pace Thick ‘n’ Chunky Salsa.
I think this is the same experiment with the baseball canon, but a different video segment of it. Here they shoot a dummy with the canon. That is a punching dummy, made to hold together through repeated trauma shots, so it doesn’t really behave like a human body would.
But I have it set to start where the ball hits the chest and you can see the shock wave radiate out and the whole chest try to suction back in and follow the ball through the hole it punched. This video gives an idea of what forces a projectile unloads onto the target, even if the target doesn’t behave like a body.
Besides that, I suspect a cannon slug hitting a human is roughly equivalent to a 55gr. bullet hitting a watermelon.
Right. And that’s a “supersonic” baseball. A sabot round out of a tank has a lot more mass, and is traveling at least a half mile per second. Intuitively, it’s hard to imagine the kind of energy we’re talking about.