My Fourth of July Tribute

Okay, so Captain America’s shield is made of vibranium, right? That’s why the mighty Thor can smite it with his hammer and have none of the energy transfer through. Because otherwise Cap would be liquefied, since his only super power is being 1/10,000th as tough as Thor. Got it.

 But then why should the bad guys mind getting hit with the shield? It absorbs all the impact energy, right? That’s the only reason it’s useful. Which means Cap should be able to punch me in the face with it all day and it wouldn’t hurt.

 Solution #1, from a comic über-geek I know: it’s not vibranium, it’s a vibranium alloy. How exactly does this allow energy to transfer into a bad guy’s face but not into Cap’s arm? My über-geek doesn’t know. He’s just nitpicking.

 Solution #2, from an honest-to-god physicist who asks, “if you take the energy of Thor’s hammer striking Captain America’s shield, there’s a large amount of kinetic energy in the hammer that is transferred to vibrational energy in the shield. If the vibranium absorbs it, that energy has to go some place, and where does it go?” His answer? It becomes light:

In the first Avengers film …when Thor strikes Cap’s shield… you see this enormous blast of light in the visible and ultraviolet part of the spectrum. So the vibrational energy is being transformed into light energy, which then radiates out from the shield.

 Okay, so this solves the conservation of energy problem, but it hardly explains why getting hit by the shield hurts. When it hits me it should light me up, not knock me out.

 Solution #3, from a physicist and comic geek: vibranium is part battery, part capacitor, part indestructible shield stuff. When all that impact energy hits the shield,  

the atomic bonds in the shield… must be able to store that energy in some form. […] If the energy is being stored in the bonds between the shield’s atoms, that could explain the variability in the shield’s physical characteristics…

 …you know, so that sometimes it hits something and sticks into it like a blade, but other times it caroms around like a pool ball.

 I kinda like this explanation. The only problem is that nobody ever mentions it. Like, not even once. If Howard Stark created the shield, surely he ought to have figured this out.

 So, for this Fourth of July, I give you Solution #4: vibranium is a perfect reflector. We have to take some liberties with Newton’s third law, but basically it’s like this: in the case of an ordinary shield (or any other physical object) every time something hits the shield, the shield hits back. That’s the third law at work: for every action there is an equal and opposite reaction. Some things, like billiard balls, are good at reflecting the energy back without absorbing a whole lot of it into themselves. Other things, like eggs, aren’t. Thus eggs are fragile and billiard balls are both hard and bouncy. So here’s my pet theory:

billiard ball : egg :: vibranium : everything else

Vibranium must be the billiard ball multiplied to the power of billiard ball. It’s so good at reflecting energy that every time an object transfers equal and opposite reaction energy into it, the vibranium transfers that energy back too. It must do this so efficiently that all impact energy is reflected back out, smashing the bejeezus out of whatever’s on the receiving end.

 Like I said, I’m taking liberties here, but Solution #4 explains why the mighty Mjolnir doesn’t shatter Cap’s arm and explains why it still hurts to get clocked by the shield. In fact, it even explains why Captain America hits so much harder than you’d think he could (given his relative power level on the team): the action his shield puts into your face is actually made worse by the equal and opposite reaction your face puts into the shield.