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Speaker 1: Stuff Works. Hey, brain Stuff, I'm Christian Sager. The official
Speaker 1: Marvel Comics database says that Captain America's shield is a
Speaker 1: metal disc that's approximately two point five feet in diameter
Speaker 1: and weighs twelve pounds, But Rheta. Laine at Wired Magazine
Speaker 1: did some math and figured out that it would be
Speaker 1: more likely to weigh forty three point nine pounds, despite
Speaker 1: the shield being made of a unique alloy combining vibranium,
Speaker 1: which is a fictional metal steal, and an unknown third component.
Speaker 1: Elaine also figured out that the density of the shield
Speaker 1: would be somewhere between eight thousand, seven hundred and sixty
Speaker 1: seven and four thousand, three eighty three kilgrams per meter cubed.
Speaker 1: That is, somewhere between the density of iron and titanium. Now.
Speaker 1: In the Captain America comics, the story goes that Dr
Speaker 1: Myron McLean was attempting to replicate hercules golden mace by
Speaker 1: fusing vibranium with an experimental iron alloy. Some say it
Speaker 1: was a steel alloy, but even McClain didn't know what
Speaker 1: it was because he fell asleep when an unknown catalyst
Speaker 1: was introduced to the process. He was never able to
Speaker 1: duplicate the process, so the government painted the disk and
Speaker 1: gave it to Captain America. But how would you forge
Speaker 1: such a thing, especially since metallurgy is so complicated. Just
Speaker 1: the forging temperature alone depends on the materials carbon content,
Speaker 1: it's alloy composition, maximum plasticity, and the amount of reduction required.
Speaker 1: Was it heated by induction or by continue was fuel
Speaker 1: fired furnaces With a material this unique, you would have
Speaker 1: to carefully control the heating process. Now, forgibility is how
Speaker 1: easy or difficult a material resists deformation, And since Captain
Speaker 1: America's shield is indestructible, it would have to be a
Speaker 1: very narrow forging temperature range, meaning it could only be
Speaker 1: forged for a short time after heating. With metallurgical factors
Speaker 1: like crystal structure, chemical composition, and grain size at play.
Speaker 1: The only way McClain could have diminished their influence would
Speaker 1: be by adding alloying elements, possibly compounds that easily dissolve
Speaker 1: within the metal. There are all types of elements that
Speaker 1: could have been introduced, but it's likely that Captain America's
Speaker 1: shield was forged like a super alloy. This is how
Speaker 1: metall aer just referred to iron based, nickel base and
Speaker 1: cobalt based alloys, specifically the ones that offer very high
Speaker 1: strength at high temperatures. These really high string metals and
Speaker 1: iron based grades are the least difficult ones to work with,
Speaker 1: so that would narrow down McClain's experimental alloy to iron.
Speaker 1: Super alloys are really difficult to forge because of their
Speaker 1: narrow temperature range. You can't even use regular sizing presses
Speaker 1: and hammers on them because they'll deform. They even wear
Speaker 1: down the tools designed for forging them pretty easily. They're
Speaker 1: also extremely expensive, like ten times the price of carbon steel.
Speaker 1: Sounds a lot like Captain America's shield, right, But how
Speaker 1: do we explain the shield's ability to absorb kinetic energy
Speaker 1: supposedly from the vibranium in the alloy. Usually materials absorb
Speaker 1: kinetic energy through other mechanisms like plastic or elastic deformation
Speaker 1: or dynamic fluid flow, But cap shield doesn't seem to
Speaker 1: be an elastometric material, and it's not organic like polyurethane
Speaker 1: in the movies. It actually seems to reflect vibration rather
Speaker 1: than absorb it, like when Thor hits it with Mjolner
Speaker 1: in that first Avengers movie and the shock wave flattens
Speaker 1: a whole forest. Perhaps that was because the shield reached
Speaker 1: its absorption limit. Another thing that's tough to explain is
Speaker 1: how aerodynamic the shield is. If it really weighed forty
Speaker 1: three point nine pounds, it would be difficult to throw,
Speaker 1: even for a guy in peak physical condition like Steve Rogers.
Speaker 1: In the comics, Tony Stark actually puts electro magnets under
Speaker 1: the shield to help control it in midflight, but Captain
Speaker 1: America later ditched them because they upset the shields natural balance.
Speaker 1: It seems like the soldier and the shield are made
Speaker 1: for each other. Check out the brain stuff channel on YouTube,
Speaker 1: and for more on this and thousands of other topics,
Speaker 1: visit how stuff works dot com.