Guest Post: 'Fantastic' Flub

And now, a guest submission from a new contributor, Brian Kilkowski, a.k.a. metaphysician, on some cringeworthy science in the Fantastic Four film. Don't worry if you haven't seen the film; there are no spoilers to speak of.

--------

In any story involving the Fantastic Four, there will be science, comic book
and otherwise. Overall, the movie was actually pretty good from this angle.

The comic book science was nothing to bother anyone who could accept the
basic movie premise. Several scenes also made fairly good usage of at least
plausible actual science (the capture of Reed Richards and the defeat of Dr.
Doom, specifically, were good). However, one scene stood up and made my
inner scientist cringe. That, was the test scene for Johnny Storm, the
Human Torch. There were two significant elements of the scene, one only a
minor nitpick, the other. . . not.

Firstly, Johnny's temperature peaked out at just under 4000 Kelvin when the
test was cut off. This was referred to at one point as being "as hot as the
sun." This is technically correct, but misleading. One can find
temperatures of 4500 K in the sun; specifically, that is the temperature of
a sunspot. However, sunspots are also, by far, the coldest portions of the
sun. In comparison, the core of the sun is 15 million Kelvin, and even
normal temperature portions of the photosphere (where sunspots are located)
are 6000 Kelvin.

(As an aside, 4000 Kelvin is also roughly the melting point of diamond, the
substance with the highest known melting point. Whatever Reed made that
test chamber out of, I hope he's selling it to NASA. However, I don't
consider this a nitpick, as Reed's whole schtick *is* "supergenius
scientist," after all.)

The second, and by far worse problem, is his claim that Johnny could have
"ignited the atmosphere" if his heat went any higher. Firstly, in order for
any of the atmosphere to burn at all, requires that some react with the
oxygen in the air. Oxygen does not burn; it facilitates burning. Second,
in order for this to "ignite" the atmosphere, the reaction in question would
need to release more energy than it absorbed, sufficient to power further
combustion.

The possible reactants include Nitrogen, Argon, Carbon Dioxide, and Water (vapor). The second two are themselves already combustion products (of carbon and hydrogen, respectively); they are not going to further combust, but rather, they would be decomposed into their components, thus absorbing energy. Argon is a noble gas; the only compounds it forms at all are unstable molecules ( heh ) with Fluorine, and only in exacting laboratory conditions. This leaves Nitrogen as the only even vaguely possible reactant, though only in the sense that it is not a combustion product
itself and isn't a noble gas. Thankfully, atmospheric nitrogen naturally
exists in its most stable possible form. While sufficient heat can combust
nitrogen, the resulting chemical reaction absorbs energy, rather than
releasing it. This is precisely the reason why both ATP and TNT contain
numerous nitrogen atoms; the bounds they form contain much energy, while the
nitrogen itself is in a less stable state, thus allowing for the molecule to
readily be broken down to release the energy.

There is also experimental, as theoretical, evidence for the non-danger of
atmospheric ignition: specifically, the aboveground testing of nuclear
weapons. The US alone has done hundreds of such tests, and even a Hiroshima
class bomb generates temperatures far in excess of 4000 Kelvin. The fact
that we are still here, is proof enough that a "mere" 4000 K superhero is no
threat to life as we know it.