Sunday, September 27, 2015

Avengers: Age of Ultron

The year is 3015. Sometime in the month of September. We lost our calendar, and I have lost track of the days, so I am not sure when.

The Avengers movie was amazing! I enjoyed every second on it. The wit was great, the banter was great, the doomsday plot was far fetched but forgivable, the super heroes kicked some major bad guy butt, all in all it was a great movie. Strangely enough, I discovered this week that of all the books in the library near us to survive, one of them was a book on the physics of superheroes, called "The Physics of Superheroes" by James Kakalios. Flipping through it, I found chapter 13, which is on conduction and convection, two of the types of heat transfer. What better way of starting this conversation than with one of the original X-men, Iceman.

Iceman's power is lowering the temperature of himself and his surroundings below the freezing point of water, thereby freezing the water vapor in the air, and surrounding himself in a coating of protective ice. Sounds like another great hero from a great movie:

But back to the book, Kakalios points out an obvious physics question: Where does that heat go? As we know, heat is just a measure of the kinetic energy in an object. Make something colder, you are lowering the kinetic energy. And as we know, energy cannot be created or destroyed. So the energy has to go somewhere. If he was just removing it from an object (even himself), I would buy it if it is vented out to the outside air. That is how fridges work, as Kakalios point out. However, he is sucking the energy out of the air itself. Kakalios says that where the energy goes is currently unexplained, so for now we are forced to give Iceman a dubious look, and give him a nice "comic book physics" hand wave on this somewhat believable, yet improbable, power.

Kakalios goes on to talk about how snowflakes form, scratching the bare surface of Brownian motion and describing some of the complex conditions that go into the creation of a snowflake. This Brownian motion is the cause of conduction, due to the air molecules moving through the air and carrying the heat with them. This is why you have to be close to a hot object to feel the heat off it, because with Brownian motion, the air molecules do not move fast at all.

Kakalios then goes on to discribe another use of Iceman's powers: creating ramps of ice to skate around on. He freezes the water in the air infront of him, creating a continuous track for him to skate along. Alright, I'll buy it, and so does Kakalios... for the first couple of meters. As Kakalios points out, eventually, the center of mass of the ice bridge would be too far out, with nothing to rest on. As soon as that happens, the whole bridge would collapse or tip, bringing Iceman crashing down with it. Fixing this problem is easy. Kakalios suggests just making ice pillars between the ground and his bridge, while I figure he just needs to get really good at manipulating physics, like whoever made this is:

Kakalios then talks about the X-man Storm, with the power to control weather and winds. The great Stan Lee evidently found Storm's power's implausible, even after creating the Hulk. As Kakalios explains, it is likely that Storm's power is as simple as controlling thermal gradients, and using convection heating to cause the winds to flow. Air will flow from a hot area to a cold area. Thanks to that, she can just heat up the area she wants the winds to flow from, and physics will do the rest.

Finally, Kakalios mentions another form of heating- radiation- in the context of the age of the earth and calculating it using thermal conductivity. He talks about Lord Kelvin and Darwin, though no superheroes are mentioned.

Well, that is all on superheroes now. We will watch the ageless classic 2001: A Space Odyssey tomorrow, so we will see how that goes.

1 comment:

  1. OK, good to see you tackle a new branch of physics, one we'll get into in the coming weeks. Thermal physics is a very rich area, and has some interesting effects of its own, such as Brownian motion. As always, I like the media inclusions in the post. The only improvement would have been to go into a bit more detail on the core physics, such as heat capacity and how much heat would have to be removed from the air.