I’m a huge fan of action movies, even with their occasional disregard for the laws of physics. I am also a huge fan of science fiction. However, often times script writers forget the first part of that genre label: science. CGI is all well and good, but it is not a good replacement for a good, imaginative, scientific base. And when the writing actually gets in the way of the plausibility, the movie becomes ruined. A perfect example of this is the recent action movie, G.I. Joe. I’m not slighting the high-tech suits, or the little metal-eating nanobots… they were brilliant. What bothered me was the ending, where the villain decided to destroy his sub-polar-ice-cap fortress. He didn’t do this by simply detonating the whole structure, but instead by blowing up the ice above and having it FALL DOWN and CRUSH his vast base on the ocean floor. I’m sure the passengers of the Titantic would have appreciated this variant of artic ice.
You see, water is one of the few materials which actually becomes less dense as it freezes, which means that 1 cubic foot of ice weighs less than one cubic foot of water. When an object whose density is higher than water is placed in water, it will sink, displacing as much water as its volume. However if an object has a density less than water, it will sink into the water until the displaced water weighs as much as the object. Since ice is only marginally less dense than water ( .91 vs. 1 gram per cubic centimeter) a block of ice placed in water will have roughly 90% of its volume beneath the surface, but never 100%. This is what makes an iceberg so dangerous: the 90% of the ice below the surface can be in any shape and very far away from the visible 10%.
Science fiction can inspire children to pay more attention to science and engineering disciplines, but those who write it had better already have at least a general grasp of the laws of physics. The legendary science fiction writer, Jules Verne, wrote truly great, and in his day imaginative, works. They are made even more fascinating by how many of his fantastical ideas finally did come true. In the book, Paris in the 20th Century he predicted a world of skyscrapers, calculators, automobiles, and world-wide communications. Pretty bizarre ideas for the year 1863! Good science fiction then, is that which one day becomes science non-fiction.
Unfortunately, no matter what nano-bots are invented, or how many mach the fastest fighter jet can fly at, artic ice will never sink on its own.