Monday, June 28, 2010

Unobtainium This: Scientific Errors in Avatar

I've quit gauging the science of Hollywood films--or any films, for that matter. I sense that most writers of science fiction films pick up an issue of "Popular Science" for inspiration. They stretch vague generalizations--whose exploitability is already exaggerated--about the nature of space and reality without fully exploring the causes and repercussions of those things.

As a person studying science, I found this irritating for a long time, but I eventually gave up. So long the plots and writing of films engaged me and the rules of the world created were consistent, I suspended my own sense of reality for the time my eyes enjoyed the film. I simply wanted to enjoy what I watched.

When I saw Avatar, I applied this policy. The plot wasn't great, but the visuals were fun. I accepted and joined the collective ride. Then I read this article, which opened with:
"The producer of "Avatar" is fond of saying that writer and director James Cameron does not write science fiction, he writes science fact."

The link is long since dead, but the rage I felt when I first read this was uncontainable... or perhaps, unobtainiumable. Either way, it's boiled beneath my skin for months and erupts here, now:

+ Floating Islands
The article I linked to above first discusses James Cameron's attempt at rationalizing the existence of floating mountains. They're simply not possible--not in the way the movie portrays and not with his explanation.

Cameron claims the mountains float because of superconductivity. He claims that unobtainium--the desired goal of the human colonists in the film--superconducts, and because Pandora is loaded with the stuff, it makes giant floating mountains.

What Cameron is referring to is something called the Meissner Effect. In short, if a magnet is placed near a superconductor and the conditions are right, the magnet can float. This is why unobtainium--when displayed in the office of the stock character "Greedy Corporate Bureaucrat"--is always floating in some kind of little... circle thing, probably a magnet.

This cause for the mountains' levitation would have caused major physical problems. For example, watch this video of the real Meissner Effect:
Notice something--the magnet floating above the superconductor spins. This has to do with the way the magnet ends up floating in the first place. Just remember, the floating islands in Avatar were completely stable. None of them did flips or rotate, they stayed pleasantly upright.

It's not just that the islands were too stable to be supported by the Meissner Effect; they lacked its most fundamental aspect--the magnetic field. One of the fundamental properties of a magnetic field is that wherever there is a changing magnetic field, an electric current is induced. Even the Earth's magnetic field induces small currents in boats as they move throughout the globe.

The Earth's magnetic field is relatively weak--assuredly, it doesn't make islands float. If the islands in Avatar were held up by magnetism, any ship passing through would experience powerful induced currents in the hull of the ship. These currents would wreak havoc on the ship's on-board electronics, not to mention the hull itself. The currents have to discard their voltage somewhere; it would go right into the hull, causing the ships to heat up and explode.

I didn't see anything like that.

+ Large-scale Bioluminescence on Pandora is Improbable.
Bioluminescence is the production of light by organisms. Lightning bugs, of course, produce some light, but it was found en masse deep in the Earth's oceans. Organisms in these regions receive no light from the sun at all, and they adapted to these conditions accordingly. The light they produce has specific purposes--finding prey, attracting prey, communication, and others I can't list off the top of my head. This is a product of natural selection--residual limbs, such as the human appendix, exist, but nature is very good at plucking off inefficient or unnecessary organs.

In Pandora's case, the bioluminescence really serves no purpose. Not only does everything glow, it doesn't seem to have a purpose for glowing. One of Cameron's arguments for its purpose is that Pandora has a very long night. He neglected something, though:

Pandora orbits very close to a planet the size of Saturn. It acts as a moon far larger and, as a result, far brighter than our own. It is tidally locked in the sky all night. Nothing needs bioluminescence; there's plenty of light, all of the time.

+ That is NOT Alpha Centauri
Alpha Centauri is the nearest star system to Earth. It's also a triple star system--the third companion is very dim, but the two primary stars would be easily resolved:

This image was taken by Cassini, orbiting around Saturn. The white band spanning the image is a segment of Saturn's rings. The two dots in the center are Alpha Centauri A and B.

A binary system allows for two orbital possibilities: an orbit around one of the stars--an orbit that would be unstable, insurmountably hot, and--as a result--not conducive to life, or around both the stars, but that begs the question:

WHERE IS THE OTHER STAR? If you're going to put your story in one of the most meticulously studied star systems in the entire sky, get your facts straight. Adding a second star would have been a simple change--they could do it in the 1970's, without computer effects.

Again, I don't mind fantastic voyages when they admit that they are completely made up. They make me itch, but I can deal with that. Don't, however, masquerade as some sort of scientific imagination sage. The movie fails to stand up to reality with respect to electrodynamics, gravitational mechanics, astronomical fact, and natural selection. As a result, it comes with little surprise that one of the science advisors for the film claimed to have received a PhD that he was never awarded.

Get your facts straight before you step into science, or science will step on you.

Friday, June 11, 2010

Occam's Machette: The Betrayal of Simplicity

I watched a God/No God debate this evening. I generally avoid these; I only leave angry. This one, however, had the banana morons in it, so I had to indulge.

I noticed a common thread during the debate--one spanning beyond the debate itself into arguments of other evangelicals--the use of "simple" arguments in favor of deity-centered conclusions. The simple, "common-sense" argument is effective, especially for those wishing to validate their own beliefs. The one abused most blatantly in the debate above is the creation-creator argument--everything with a purpose must be a creation, every creation has a creator. The creator of man--we call him God. This argument implies that everything has a purpose and establishes that with a few examples.

This argument has it's flaws, and I'm not here to disprove them. The argument continues to be used because it's simple. It's built on simple analogy between all things--everything's a creation, creations have creators. What really makes it hard to fight something so simple is that the counter-arguments--those that demonstrate the logical fallacies present in such "proofs"--are often long. This is because breaking down logical fallacies is difficult. It requires precise definitions and postulates to explain how common sense has been twisted in favor of a particular conclusion. It requires deconstructing an argument piece-by-piece to point out gaps. This takes time and, often, very wordy constructions because it veers on the abstract frontier of language.

Wordiness has another disadvantage; generally, it displays a lack of confidence and strength and can imply guilt. Someone who has to talk a lot is often defending themselves, and someone who has to defend themselves, we generalize, did something that requires them to do so. We rarely associate defense with someone being attacked; instead, we associate defense with someone hiding something. That sounds backwards, but guilty people defend themselves, and humans stereotype the guilt of the defensive guilty on to the defensive. Guilty people are generalized to have convoluted defenses full of lies and rhetoric and are often false, making--through generalization--wordy people false.

This isn't always the case, of course, but it's how we perceive someone trying to make a complex--perhaps insightful--point in a debate. Meanwhile, someone trying to follow this may become lost or bored, or view the speaker as weak and defensive, or even pretentious. Another generalization of people who speak quickly are smart people--for doctors and hackers on television, all they have to do is ramble really fast:

Looking smart is not always good. In many situations, it's very bad because it's just as asinine as trying to take the moral high ground over another person--effectively, an argumentum ad hominem. Looking smarter than your opponent makes you appear more likely to be right. It also makes you look like an ass, so people ignore you.

There's also a practical reason for longer arguments to be false--there's more room for error. In part, it's an error of logic itself. Logic itself has always been part of a mystical dominion. The Greek philosophers--the ones who established the Western tradition of knowledge--loved logic because it was perfect; they thought it beyond our mortal world. This disconnection from reality is indicative of logic. Using logic requires generalizations and assumptions; application to the real world involves squashing complex systems into abstract postulates.

In this process, information is lost. Most logical steps require some small approximation, and by the end of a long chain of logical steps, false conclusions can be drawn with carefully selected postulates.

With a plethora of reasons that make longer arguments harder to fight in the public eye of debate, longer arguments are judged--perhaps incorrectly--as wrong. It ends up a backwards perversion of Occam's Razor--the idea that out of a possible list of hypotheses, the simplest is generally correct. That, however, doesn't mean that it is always correct, and that idea can easily betray us, causing us to discard hypotheses that are longer because of our impatience instead of weighing their merits.