The geochemistry of the "Blood Falls"

By the way, a little note from the last column: a reader that is studying economics brought to my attention that matrix modelling is used in the discipline of economics. Nice!

I have to admit, it's a striking image: a glacier that bleeds. It's like something out of an Elric novel, or Ozzy Ozbourne's subconscious. Not only does it make for surreal and sensationalist photographs, but it might tell us a little something about the history of life on earth and possibly where we're headed.

The chemistry behind the "Blood Falls" is astonishing, since it has been a fjord lake trapped inside a small glacier. The water of the antarctic fjord was sealed off by glacier ice over 5 million years ago, before humans stood erect. This caused the water to acquire unique chemical properties that are downright non-earthly.

We take it for granted that water flows around and has contact with the air. When it doesn't, water undergoes a chemical change as a result of the bacteria living inside of it, which chew up the dissolved oxygen. As the environment is closed off, eventually the bacteria burn through the oxygen. Now, oxygen is important in organic chemistry because of its property as an electron acceptor. Deprived of oxygen to bond with, bacteria switch to the second best electron acceptor, which in water is typically nitrogen. Nitrogen is burned through relatively fast, and then they switch to sulfates, creating sulfides...which explains the bad "rotten" smell of stagnant water (and you've gotta love any chemical whose most distinctive characteristic is smelling bad). Sulfur is actually in the same column of the periodic table with oxygen and has similar electron-accepting properties, after all.

(By the way, a note for fans of organic chemistry: you might have heard the term thioether refer to sulfides and so there's a great instinct to think both are the same thing. Sulfides and thioethers are similar but not the same thing. Sulfide is a term to describe pretty much anything that's sulfur with two atoms of carbon including those created by nonliving processes, whereas thioether specifically refers to sulfides created by organic processes.)

Now, sulfates are very reactive with iron. In fact, they're responsible for the process of corrosion. So if you throw some sulfides together with iron, and it catalyzes it, speeding it up until it becomes bright red rust. This gives the red falls it's color. But in the trapped bacteria of the red falls, the iron and the sulfates are actually used as a part of the reaction cycle. This is something that has never been seen before in any living thing on earth.

Let me explain that: these are single-celled organisms that produce their own food...with iron, and without sunlight or much oxygen.

How is this important to understanding the history of life?

Well, there was a period of time around 850-650 million years ago, called the Cryogenian, when the entire planet earth was frozen. There were glaciers in the tropics and the earth's ocean was all ice. If you stop and think about it, that would make the earth a really dead world. There's a lot of back and forth between scientists as to whether the entire earth really could have been frozen...because how could life survive something that shocking for millions of years? Something like this, where a totally different biochemistry for food-producing bacteria is discovered, can change the entire history of life.

Likewise, something like this can also tell us about periods of time that earth's oceans have been deprived of oxygen, called anoxic events. When ocean currents don't circulate, oxygen isn't sent into the water. If oxygen isn't sent into the water, sulfur's used instead, and this produces poisonous hydrogen sulfide. Water itself becomes very lethal to living things - creating "dead zones," and would have turned a deep green hue from the bacterial blooms, not to mention smelling like rotten eggs. These accompany a heating of the earth's atmosphere from events like super-global warming. This in fact might have been part of the cause of the largest mass-extinction in earth's history, between the Permian and Triassic.

This is one of the most exciting areas in the history of life, because it's cutting edge. The role of anoxic events in the hot global temperature that we associate with the age of the Dinosaurs isn't new, but in fact, the idea that anoxic events may have been the agents of mass extinctions are only as old as this decade.

All of this may sound scary and familiar, because it is happening right now. Oceanic deoxygenifaction - or oceanic suffocation, to use the scarier and sexier term - is one of the more anxiety-inducing effects of global warming, huge areas of deoxygenofied water where there's no life.

I usually have some kind of pro-intellectual moral attached to these discussions on cutting edge science, and here's the one for today: there is no such thing as useless scientific research. I am outraged by politicians that decry genetic research, for instance, as a giant waste of time: Sarah Palin was ticked off by the study of fruit flies, despite the fact that the guys studying fruit flies used the information to understand and prevent human birth defects, something that won them the Nobel Prize!

Studying something like this weird freak event may sound like a waste of time because it's a one of a kind ecosystem. But it has so much to tell us about the history of life, possible future changes in the earth with real consequences for human beings, and perhaps even a way for life to work on other planets. Sorry, Sarah, but the only real waste of resources is on ignorance.

The Science of Avatar

It’s not often that I recommend a movie for the scientific content, but James Cameron’s “Avatar” is downright mindblowing. “Avatar” is one of the most scientifically literate movies seen in some time. What “Jurassic Park” was to genetics, “Avatar” is to ecology and biology. In addition to the pretty colors and effects, it’s obvious that a lot of work was placed into figuring out the plausibility of the rain forest planet Pandora’s life forms.

You can always expect scientific accuracy from Cameron, who knows his oysters, and proved it, with "The Abyss." I actually first saw that film in high school Marine Biology!

You know, usually I’m irritated by all the tie-in books that accompany a major movie release, but this time, I’d actually be interested in checking them out. It’s obvious that a lot of thought was placed into the scientific verisimilitude of this world ecology, and that one of the limitations of a movie like this one is that we don’t see any of that work, as it is in the background. I’d love to read more about the world and then come back and see the film. I’m sure my appreciation would be improved.

One of the occasions where it was obvious they knew what they were doing was in a sequence where the characters meet a weird carnivorous creature, who goes after a herd of herbivores…but backs off when he sees them in a herd. Only then does he think about attacking our human heroes. This was a startlingly logical set of behaviors! Incidentally, the ratio of herbivores to carnivores is spot-on. Carnivores are rare in any ecosystem, since they require a lot of herbivores to maintain themselves.

Some of the great sky-shots are dominated by a giant Jupiter-like planet in the distance, which leads me to think that Pandora may not be a planet in the traditional sense, but a moon of a gas giant. The idea of Pandora as a moon may be a little unimpressive, but consider that there are moons in our solar system that are near planet-sized. Saturn’s moon Titan, the largest moon in the solar system, is bigger than Mercury and Pluto.

Actually, this makes a great deal of sense of you consider the vast biodiversity of Pandora life. I mean, a single, big planet-killer asteroid and the whole ecosystems would have to start from scratch. But imagine a very close, huge gas giant nearby, with gravity that deflect nearly all objects. Considering how many stellar objects are deflected by earth’s moon and multiply that.

All of the most exhilarating moments of the film are set on winged riding birds, which the Na’Vi, the blue furry space monsters, can actually ride. The idea of birds growing to be that huge…and able to carry 12 foot giant riders…defies the laws of biology at least on earth. There is no more expensive biological process than flight, after all.

But the movie, in a first, actually pays attention to why flight for huge creatures is possible, which surprised me. The atmosphere is far denser than that of Earth's, which means it can provide greater buoyancy. It's also stated that Pandora has a lower gravity, which also reduces the force of drag.

What I find impressive is that most of the reptilian flying creatures have four wings, two for control on the legs. This sounds a little exotic, but it is true that a dinosaur, discovered in China, called microraptor had this very feature!

The script states that Pandora orbits Alpha Centauri A, the second closest visible star to earth that is 4.3 light years away and it takes five years to get there, which means that the ships in this future can travel at around 85% of the speed of light. I know Alpha Centauri gets mentioned a lot in science fiction, but I kind of like that Cameron felt the need to specify Alpha Centauri A, since Alpha Centauri is a double-star (technically a triple if you count Proxima, a brown dwarf), both of which are 23 AUs apart.

All of this is nothing before a science fiction idea that appears near the two-thirds mark that is so original and unexpected and entertaining that, in all honesty, I think revealing it counts as a spoiler. You’ve been warned!

Early on in the film, it is established that the giant natives venerate a type of life-force existing on the planet, which the main character says consists of . They have nerves at the base of their ponytails that let them “plug in” and link up to animals that they ride. That’s cool enough, but what’s interesting is that all the trees on the planet link up to form a gigantic neural computer network. Sigourney Weaver, who plays a brassy female scientist, said that each tree had 10⁴ connections to the trees around it, and there were 10¹² trees on the planet, which means this giant biological/chemical computer network has more processing power than the human brain. (This is not only true but an understatement. Each person has 10¹⁰ neurons and each has 7,000 connections) This means the entire planet is one giant living computer.

I was expecting some dull, unoriginal idea about life forces and mother goddesses – as unwelcome in a science fiction movie as an abortion in a Disney cartoon. This was actually a great idea.

As for the visual look, it really is everything everybody says it is. Me, a science student, and my friend getting her masters in visual arts, were equally blown away.

As for the film’s creative elements, I have to admit that it was not one of Cameron’s best movies at all, even though it's obvious the movie has a conscience. The biggest problem is that it is predictable. I can see every plot development coming from a mile away. There was one that was especially ridiculous one that goes something like, “only our greatest warriors have ridden the magical orange pterodactyl.” Followed by, “gasp! He has ridden the magical orange pterodactyl!” Still, it’s great to see Sigourney Weaver in anything again. And yes, she has an avatar too, something not a single trailer mentions.