Mythbusters - "Boomerang Bullet"

[Trekker4747]

IIRC, tonight is the 2009 season "finale."

So, after tonight I wouldn't expect to see any new episodes until mid/late spring.

From Wikipedia:

Can ricochets of a bullet fired by you kill you in a closed space? And a Monty Python myth with a bouncing castle.

 

[shivkala]

Official word is April.

 

[Trekker4747]

Official word is April.

Which, hey, is in mid Spring!

 

[ambessalion]

great......the episode is interest in a 'cutsey' sort of away but nothing really all that exciting....

 

[Christopher]

360-degree ricochet: Interesting to learn how much more complex ricochets are than you'd think. Since bullets deform on impact -- and are generally designed to do so in order to deliver more energy and damage to the target -- it stands to reason that a ricochet wouldn't be as simple as a ball bouncing off a wall. It is, I believe, an inelastic collision rather than an elastic one (though I've always had a bit of trouble keeping those two straight).

Though I'm wondering... that third hit off concrete with the ball bearing came in at 60 degrees and left at 60 degrees, so I'm wondering what would've happened if the initial shot had been at 60 degrees. Still wouldn't translate to a bullet, though, I guess.

I also didn't know that "full metal jackets" weren't entirely full, or that there was such a thing as a "total metal jacket" (which literally means exactly the same thing as "full," but I guess they had to call it something since the "full" term is something of an exaggeration).

The test involving shooting through a bent pipe was interesting, but what was really cool was that pipe-bending machine. It's Bender's great-to-the-nth granddaddy! Who knew they actually did make complex machines whose only purpose was to bend metal? And in-jokes aside, it was just cool to watch that nearly-circular pipe rolling back and forth as the machine bent it.


Tree catapult: Kind of unusual for the Mythbusters to do a full-scale test before a bench test. Amusing result, though. The small-scale tests were interesting, figuring out things like trimming the branches and adding a tether. (And we got that cool high-speed shot of the second action figure landing smack on its head! Ow!)

I'm not entirely convinced by the results, though. What kind of conifers did they have in medieval Europe, assuming that's where this myth comes from? They should've used one of those specifically. And the tree in question could've been unusually tall or able to bend farther.

And I don't get Grant's objection about the number of soldiers and horses it would take to apply 2400 lb. of tension, considering that earlier he had been able to run up a ton of tension just using an old-style hand winch (or "come-along" as they were calling it). There's no reason they couldn't have had similar force multipliers in medieval times. At least a block and tackle sort of thing.

And we discover that Jessi has a large star tattoo under her left armpit. Odd place for a tattoo.

Hmm, if this was the season finale, does this mean we won't be seeing Jessi again?

 

[Mr. Adventure]

I would have been interested in seeing a high-speed rifle take a crack at the ricochets.

And we discover that Jessi has a large star tattoo under her left armpit. Odd place for a tattoo.

I thought that was odd as well. Kinda cool though. However, if I got one I think the hairy star effect would not be so good....

 

[Brent]

They totally missed the boat by trimming the tree, all they did was turn it into catapult.

They should have just put buster at the very top of the tree as it was, and pulled it back as far as they could and let her rip.

 

[Christopher]

They totally missed the boat by trimming the tree, all they did was turn it into catapult.

They should have just put buster at the very top of the tree as it was, and pulled it back as far as they could and let her rip.

Umm, that's exactly what they did at the start of the myth, and it didn't work. And the whole point was to turn it into a catapult, since that's what the myth postulated that the medieval armies did. They explained quite clearly why keeping the branches on the tree kept it from doing the job. The branches create air resistance and slow the tree down, and their extra mass weighs it down, both of which prevent it from getting the necessary speed to fling the "corpse."

 

[Roger Wilco]

I like this sort of episode - nothing really that spectacular, but thorough testing of all possible angles, which doesn't leave any questions open (at least for me ).

I was very sceptical of the tree myth, especially for the reason that castles simply were not built next to forests (or the forests were deforested) because it's much easier to defend against a siege when there's lots of open space next to the walls. Having a castle next to trees kind of defeats the purpose of even building walls in the first place. But it was interesting to see it tested out anyway.

The bullet myth was more surprising. Before they started, I expected it to be very unlikely, but not impossible as it quickly turned out to be.

eta:

I'm not entirely convinced by the results, though. What kind of conifers did they have in medieval Europe, assuming that's where this myth comes from? They should've used one of those specifically. And the tree in question could've been unusually tall or able to bend farther.

Yeah, I thought about that too when they tested the different trees in the small scale, but really, I can't see it changing anything since the testing so far off the mark. The tree they did use had a very nice bounce, I doubt you can get much more out of any sort of tree.

 

[Christopher]

I was very sceptical of the tree myth, especially for the reason that castles simply were not built next to forests (or the forests were deforested) because it's much easier to defend against a siege when there's lots of open space next to the walls. Having a castle next to trees kind of defeats the purpose of even building walls in the first place. But it was interesting to see it tested out anyway.

That's an excellent point.

Yeah, I thought about that too when they tested the different trees in the small scale, but really, I can't see it changing anything since the testing so far off the mark. The tree they did use had a very nice bounce, I doubt you can get much more out of any sort of tree.

But that's just what I mean. The myth wasn't whether this was possible in general, but whether it was possible for people in a specific part of the world in a specific era to have done it. So the testing should've been limited to the resources those people would've had available. Just like, say, the Chinese rocketry myths are based on the types of powder and materials the medieval Chinese had available rather than more modern, better equivalents. The question is, could the conifers found in Europe be as springy as a Douglas fir? If not, then using a Douglas fir wouldn't have been in keeping with the parameters of the myth.

Though your point that no castle would have a forest close to it anyway pretty much renders the whole thing moot.

 

[Brent]

They totally missed the boat by trimming the tree, all they did was turn it into catapult.

They should have just put buster at the very top of the tree as it was, and pulled it back as far as they could and let her rip.

Umm, that's exactly what they did at the start of the myth, and it didn't work. And the whole point was to turn it into a catapult, since that's what the myth postulated that the medieval armies did. They explained quite clearly why keeping the branches on the tree kept it from doing the job. The branches create air resistance and slow the tree down, and their extra mass weighs it down, both of which prevent it from getting the necessary speed to fling the "corpse."

They used the wrong trees, I won't be satisfied until they use trees that were actually used close to real castles. They also needed to put the dummy higher on the tree, at the very top.

 

[Christopher]

They used the wrong trees, I won't be satisfied until they use trees that were actually used close to real castles.

As Roger Wilco pointed out, there probably were no tall trees that were actually close to real castles. Castles were designed as defensive fortifications and as such were generally intended to be the highest objects around, with nothing nearby tall enough to allow anyone to get over the walls. I imagine there are modern castles that have forests next to them, but that's because they're no longer used as defensive structures; the whole idea of castle walls as defense was pretty much rendered obsolete when gunpowder and other explosives came along. When they were actually used for defense, they probably cleared the land for a fair distance around.

They also needed to put the dummy higher on the tree, at the very top.

Presumably the wood on the top branch is too flimsy; it wouldn't have supported the weight of the dummy and wouldn't have done any good. I assume they got as close to the top as was feasible.

 

[Brent]

Not acceptable, until they do it right it never happened.

 

[Dac]

Not acceptable, until they do it right it never happened.

Seriously though, why didnt they use a Child substitute? I mean, its not pleasant, but If I were in charge of a commanding army and had several children die of a deadly plague, you'd stand much better chances of launching them from a tree than you would a full sized man. Less weight and air resistance.

 

[Christopher]

Seriously though, why didnt they use a Child substitute? I mean, its not pleasant, but If I were in charge of a commanding army and had several children die of a deadly plague, you'd stand much better chances of launching them from a tree than you would a full sized man. Less weight and air resistance.

^Uhh... why would a besieging army have children in it?

 

[Dac]

Seriously though, why didnt they use a Child substitute? I mean, its not pleasant, but If I were in charge of a commanding army and had several children die of a deadly plague, you'd stand much better chances of launching them from a tree than you would a full sized man. Less weight and air resistance.

^Uhh... why would a besieging army have children in it?

Good point. I doubt we'd have any way of making sure, but given the shorter lifespans back in those times, and the important role children and young people had in those times, I think its a fair bet that a 13 or 14 year old would have joined an invading army if it meant you got some food. I also doubt anyone would have really cared if it meant another person in your ranks.

 

[Christopher]

Oh, I thought you meant small children. But would the weight difference between a 13-year-old and a full-grown adult be that substantial in relation to the force imparted by the tree? I don't think it'd make that much difference.

 

[Roger Wilco]

Another thing I was wondering about - haven't catapults, trebuchets etc been more or less common knowledge for a really long time already? I'm not sure that kind of improvising to use a tree would be necessary to throw a body over a castle's walls.

 

[Christopher]

Good point. It stands to reason that a besieging army would have its own catapults, siege towers, and the like already, and wouldn't need to MacGyver something up out of a tree. And if they were short of catapults and needed to make one out of the local timber, they'd just cut down some trees and make them into an actual catapult.

 

[wew]

Camp followers would probably be along with the Besieging armies in ancient times, thus the presence of children was possible. Not that they always were there.