As is somewhat the standard for me, I am way behind on summer movie watching. I am not even sure about the movies that I should have seen which I haven't yet, though I did see Man of Steel. As a comic fan, near the top of the list should have been Iron Man 3, but I think at this point that I will just wait for it to watch at home. There has been one thing kind of bothering me about the movie and that is the riding of the shock wave scene when the Stark mansion gets blown up. This is kind of a problem with action movies in general, and not really specific to Iron Man 3, but I will get around to why Iron Man is probably the worst case for riding a shock wave.
It is not really relevant that this generally is an effect which can be applied only to heroes (heroes ride shock waves, villains experience trauma and death) but there is a fair amount of bad science behind this. Explosions occur when there is a release of chemical energy (or nuclear energy - but let's ignore that because nuclear weapon do not really create shrapnel). Generally these explosions do two things, they create a shock wave and they create tiny flying pieces of debris (the aforementioned shrapnel.) The shockwave is because of the rapid expansion of air around the explosive device and is generally of secondary importance to explosions, as the flying debris essentially makes a bunch of miniature bullets. As an example take a look at this picture of a soldier that survived an IED explosion:
Luckily this guy was apparently wearing a helmet and ballistic eyeglasses, but the difference between the two is quite evident. Below the eyes they are hundred of tiny puncture wounds, just like explosives are designed to do. Thus the first major problem with riding the shock wave is that it doesn't account for all the actual dangerous stuff. Maybe the heroes good a bit bloodied but it is rarely consistent with the actual explosion
Wit the grim part of the analysis out of the way, the next major problem of the riding of shockwaves is the shockwave itself. First of all, shrapnel travels faster through air than shockwaves do, because shrapnel is a solid, and shock waves are made of gas. That they are made of gas is a good way to illustrate the problem, because how many times has a person been standing in the wind and blown off of their feet? Not just knocked down, but actually picked up and moved aloft? Almost never, it would require greater than hurricane force winds. Not to say that an explosion cannot create such winds, just that air offers extremely poor drag. For air to move anything, it would have to hit all at once, kind of like a giant pillow, but even then a pillow is not a good comparison because pillows are made of solid matter. Instead if one were to effectively ride a shockwave, they would already have to be traveling in the same direction with the same relatively energy. To compare this to a different kind of wave action, when surfers try to catch a wave, they paddle furiously to match the speed. If they just sat in the water, the wave would mostly pass underneath them. In the case of a stationary person (or worse ... one walking towards the explosion) it would be essentially impossible to ride a shock wave. Also if one was already matching the relative speed of the shock wave in order to be blown back by it, why would they need the shockwave anyway?
OK, so with the riding of the shockwave somewhat dispelled as a visually impressive but scientifically impossible occurrence in action movies, why does this matter specifically to Iron Man? It is because his origin as a super hero depends on him not riding the shockwave. If he had done so with the explosion that otherwise would have lodged the shrapnel near his heart, he would never had needed to become Iron Man in the first place.
Log in to comment