## Thursday, January 28, 2010

### The Hulk Revisited...

I've been thinking about the Hulk problem again. Specifically, where does all Bruce Banner's extra mass come from when he turns into the Hulk. It wouldn't be the first time the Marvel Universe violated the conservation of mass. As I discuss in How Many Licks?, there are serious—or perhaps not so serious—questions about how much Spider-Man has to eat to produce all that web. However, the Hulk's metamorphosis could, at least in principle, be due to some chemical reaction where he's absorbing mass out of the air. This begs the question: What volume of air would be absorbed when B. B. turns into the Hulk?

From before, we know that B. B. gains 350-580 kg. Since air has a density of 1.2 kg/m3, we can compute the total volume of air absorbed:

volume = mass / density = (350 or 580 kg) / (1.2 kg/m3) ~ 290-480 m3

That's enough to suck out all the air in a 1,500 sq. ft. apartment. Rather than beating them up, the Hulk could suffocate them with his massive vacuum.