WEBVTT - BrainStuff Classics: How Does Captain America's Shield Work?

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<v Speaker 1>Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff.

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<v Speaker 1>I'm more in Vogelbaum, and today's episode is a classic

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<v Speaker 1>from our former host, Christian Sagar. The team here around

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<v Speaker 1>the currently virtual office loves a comic book and has

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<v Speaker 1>been delighted that Marvel has been bringing that love to

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<v Speaker 1>a wider audience with its cinematic universe. So today let's

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<v Speaker 1>get geeky with a deep look into how Captain America's

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<v Speaker 1>signature shield would work if it, you know, really existed.

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<v Speaker 1>Hey brain Stuff, I'm Christian Sager. The official Marvel Comics

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<v Speaker 1>database says that Captain America's shield is a metal disc

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<v Speaker 1>that's approximately two point five feet in diameter and weighs

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<v Speaker 1>twelve pounds, but Rhet Elaine at Wired Magazine did some

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<v Speaker 1>math and figured out that it would be more likely

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<v Speaker 1>to weigh forty three point nine pounds, despite the shield

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<v Speaker 1>being made of a unique alloy combining vibranium, which is

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<v Speaker 1>a fictional metal, steel, and an unknown third component. Elaine

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<v Speaker 1>also figured out that the density of the shield would

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<v Speaker 1>be somewhere between eight thousand, seven hundred and sixty seven

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<v Speaker 1>and four thousand, three eighty three kilograms per meter cubed

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<v Speaker 1>that is somewhere between the density of iron and titanium. Now,

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<v Speaker 1>in the Captain America comics, the story goes that Dr

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<v Speaker 1>Myron McLean was attempting to replicate Hercules golden mace by

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<v Speaker 1>fusing vibranium with an experimental iron alloy. Some say it

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<v Speaker 1>was a steel alloy, but even McClain didn't know what

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<v Speaker 1>it was because he fell asleep when an unknown catalyst

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<v Speaker 1>was introduced to the process. He was never able to

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<v Speaker 1>duplicate the process, so the government painted the disk and

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<v Speaker 1>gave it to Captain America. But how would you forge

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<v Speaker 1>such a thing, especially since metallurgy is so complicated. Just

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<v Speaker 1>the forging temperature alone depends on the materials carbon content,

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<v Speaker 1>it's alloy composition, maximum plasticity, and the out of reduction required.

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<v Speaker 1>Was it heated by induction or by continuous fuel fired furnaces.

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<v Speaker 1>With a material this unique, you would have to carefully

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<v Speaker 1>control the heating process. Now, forgibility is how easy or

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<v Speaker 1>difficult a material resists deformation, And since Captain America's shield

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<v Speaker 1>is indestructible, it would have to be a very narrow

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<v Speaker 1>forging temperature range, meaning it could only be forged for

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<v Speaker 1>a short time after heating. With metallurgical factors like crystal structure,

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<v Speaker 1>chemical composition, and grain size at play, the only way

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<v Speaker 1>McClain could have diminished their influence would be by adding

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<v Speaker 1>alloying elements, possibly compounds that easily dissolve within the metal.

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<v Speaker 1>There are all types of elements that could have been introduced,

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<v Speaker 1>but it's likely that Captain America's shield was forged like

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<v Speaker 1>a super alloy. This is how metall are just referred

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<v Speaker 1>to iron based, nickel base and cobalt based alloys, specifically

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<v Speaker 1>the ones that offer very high strength at high temperatures.

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<v Speaker 1>These really high strength metals and iron based grades are

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<v Speaker 1>the least difficult ones to work with, so that would

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<v Speaker 1>narrow down McClain's experimental alloy to iron. Super alloys are

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<v Speaker 1>really difficult to forge because of their narrow temperature range.

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<v Speaker 1>You can't even use regular sizing presses and hammers on

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<v Speaker 1>them because they'll deform. They even wear down the tools

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<v Speaker 1>designed for forging them pretty easily. They're also extremely expensive,

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<v Speaker 1>like ten times the price of carbon steel. Sounds a

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<v Speaker 1>lot like Captain America's shield, right, But how do we

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<v Speaker 1>explain the shield's ability to absorb kinetic energy, supposedly from

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<v Speaker 1>the vibranium in the alloy. Usually materials absorb kinetic energy

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<v Speaker 1>through other mechanisms like plastic or elastic deformation or dynamic

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<v Speaker 1>fluid flow, but cap shield doesn't seem to be an

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<v Speaker 1>elastometric material, and it's not organic like polyurethane in the movies.

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<v Speaker 1>It actually seems to reflect vibration rather than absorb it,

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<v Speaker 1>like when Thor hits it with m Olner in that

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<v Speaker 1>first Avengers movie and the shock wave flattens a whole forest.

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<v Speaker 1>Perhaps that was because the shield reached its absorption limit.

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<v Speaker 1>Another thing that's tough to explain is how aerodynamic the

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<v Speaker 1>shield is. If it really weighed forty three point nine pounds,

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<v Speaker 1>it would be difficult to throw, even for a guy

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<v Speaker 1>in peak physical condition like Steve Rogers. In the comics,

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<v Speaker 1>Tony Stark actually puts electro magnets under the shield to

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<v Speaker 1>help control it in midflight, but Captain America later ditched

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<v Speaker 1>them because they upset the shields natural balance. It seems

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<v Speaker 1>like the soldier and the shield are made for each other.

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<v Speaker 1>Today's episode was written by Christian and produced by Tyler Klang.

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<v Speaker 1>For more on this and lots of other topics that

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<v Speaker 1>shout excelsior, visit how stuff works dot com. Brain Stuff

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<v Speaker 1>is a production of my heart Radio. For more podcasts

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