Think of the most complicated thing you’ve written. Maybe it was a report for your employer, or an essay while in college. It could even be a computer program. Whatever it was, think of all the stuff you packed into it. Now, pause for a moment to imagine creating all that without using a word processor or a paper and pen, or really anything at all to externalize thought to something outside of your head. It seems impossible. What we get with this technology–ancient as it is–is an amplification of our brain power. Besides their gorgeous techy looks, do interactive holographics like that shown in Iron Man 2, reminiscent of interfaces shown in Minority Report, offer up some of the same brain amping?

While I was still a doctoral student, I had the opportunity work with a relative of interactive holographics, 3D virtual reality data CAVEs. This particular one, at the National Center for Supercomputing Applications (NCSA) in Urbana Illinois (the birthplace of HAL) circa 1999, was a cube with back projection on five of the six walls. You wore a headset that tracked your head position and orientation, and goggles that were LCD screens that blocked images to your right eye when the projectors were rendering images for your left eye, and vice versa when the projector was displaying images for your right eye. As you walk through space or move your head, what you see in the virtual space changes as you would expect it to.

The problem that had pushed me to use this system was trying to analyze 3D motion data of a fish that I was conducting research on. I’d developed a motion capture system for the fish, which gave fantastic 3D data of the fish moving while it was attacking its prey, but looking at this 3D data on 2D computer monitors turned out to be quite difficult. Even replaying the motion from several different views didn’t quite do the trick. So Stuart Levy at NCSA put my data set into a system called “Virtual Director” and I was able to playback the data in the cave. It was something of an unbelievable experience the first time I tried it – suddenly I could walk around the animal as it engaged in its behavior, manipulate it to get any view, rotate the wand I held to wind the behavior forward or back at different speeds. Visitors particularly enjoyed my “Book of Jonah” demo where I positioned them so that they ended going into the mouth of the fish during a capture sequence.

For my technical problem, the VR CAVE was appropriate technology: 3D display and interaction for an inherently 3D data set. It helped me see patterns in the data that I had not clearly seen before, which were incorporated into some of my subsequent publications that analyzed the movement data. It was worth the effort, and the physicality of it was fine since I didn’t need to spend multiple days working through the data.

Other uses of these kinds of “direct manipulation” interfaces that mix 3D data and real world interaction have not found such a receptive audience, as people complain that it seems tiring to make sweeping (if dramatic) gestures to go through photos that would just as well be navigated through with an arrow key. As someone who still uses “vi” to edit my text with, I can relate to criticisms of interfaces that offer more than is needed.

The important question, for any given interface, is whether simplifies difficult problems of control or analysis, or gets in the way. My former colleague Don Norman at Northwestern University has contributed a great deal to our understanding of this question, in books like The Design of Everyday Things. One of my favorite examples from that book considers two different interfaces to manipulating the position of a car seat. In one interface, on a luxury American car, there is a panel of knobs and buttons almost hidden below the left side of the dashboard. To go from a state of discomfort to a new chair position requires translating your discomfort into a series of knob pulls and twists on a console of many controls with tiny labels below each. In contrast, a German luxury car had a small version of the driver’s chair in the dashboard. To move the back of your chair down, you manipulated the chair in the dashboard accordingly; to move it forward, you would move it in the direction the chair was facing, and so on. One interface placed a large cognitive load on the user to solve the discomfort problem, while the other placed minimal demands.

Another favorite example is the “speed bug” – a tab that a plane pilot puts on the edge of an airspeed indicator to mark the velocities for critical changes to shape of the wing. Were it not for those bugs, the pilot would have to remember the velocity to do the wing adjustments – and that’s not easy, because it changes with things like the weight of the plane.

The virtual fish, miniature car seat adjuster, and speed bug are all examples of interfaces that make problems easier, and in this sense, amplify our brain power. Interactive holographic interfaces can do the same for problems where space is a convenient or needed basis for navigating the information. This isn’t always apparent in sci-fi depictions of these interfaces, but their use speaks to our hope that such 3D holographic wizardry will help us cope with the flood of data we contend with on a daily basis.

Flatfish are the closest living relatives to swordfish and marlins

At first glance, a swordfish and a flounder couldn’t seem more different. One is a fast, streamlined hunter with a pointy nose, and the other is an oddly shaped bottom-dweller with one distorted eye on the opposite side of its face. Their bodies are worlds apart, but their genes tell a different story.

Alex Little from Queen’s University, Canada, has found that billfishes, like swordfish and marlin, are some of the closest living relatives to the flatfishes, like plaice, sole, flounder and halibut. This result was completely unexpected; Little was originally trying to clarify the relationship between billfishes and their supposed closest relatives – the tunas. That connection seems to make more sense. Both tunas and billfishes are among a handful of fish that are partially warm-blooded. They can heat specific body parts, such as eyes and swimming muscles, to continuously swim after their prey at extremely fast speeds with keen eyesight.

But it turns out that these similarities are superficial. Little sequenced DNA from three species of billfishes and three tunas, focusing on three parts of their main genome and nine parts of their mitochondrial one (a small accessory genome that all animal cells have). By comparing these sequences to those of other fish, Little found that the billfishes’ closest kin are the flatfish and jacks. Indeed, if you look past the most distinctive features like the long bills and bizarre eyes, the skeletons of these groups share features that tunas lack. Indeed, billfish and tuna proved to be only distant relatives. Their ability to heat themselves must have evolved independently and indeed, their bodies product and retain heat in quite different ways.

Little’s work is testament to the power of natural selection. Even closely related species, like marlins are flounders, can end up looking vastly different if they adapt to diverse lifestyles. And distantly related species like tuna and swordfish can end up looking incredibly similar because they’ve adapted to similar challenges – pursuing fast-swimming prey. This shouldn’t come as a surprise – a few months ago, a French team found that prehistoric predatory sea reptiles were probably also warm-blooded.

Reference: Molecular Phylogenetics and Evolution: http://dx.doi.org/10.1016/j.ympev.2010.04.022; images by Luc Viatour and NAOA

Ancient death-grip scars caused by fungus-controlled ants

Forty-eight million years ago, some ants marched up to a leaf and gripped it tight in their jaws. It would be the last thing they would ever do. Their bodies had already been corrupted by a fungus that, over the next few days, fatally erupted from their heads. The fungus produced a long stalk tipped with spores, which eventually blew away, presumably to infect more ants. In time, all that was left of this grisly scene were the scars left by the ants’ death-grip. Today, David Hughes from Harvard University has found such scars in a fossilised leaf from Germany.

Today, hundreds of species of Cordyceps fungi infect a wide variety of insects, including ants. Like many parasites, they can manipulate the way their hosts behave. One species, Cordyceps unilateralis, changes the brains of its ant hosts so that they find and bite into leaves, some 25cm above the forest floor. The temperature and humidity in this zone are just right for the fungus to develop its spore capsules. In its dying act, the ant leaves a distinctive bite mark that’s always on one of the leaf’s veins on its underside. And that’s exactly what Hughes saw in his fossil leaf.

Hughes originally thought that the marks were made by an insect cutting the veins of the leaf to drain away any potential poisons, something that modern insects also do. But these marks look very different – those on the fossil leaf bear a much closer resemblance to those of Cordyceps-infected ants. This is the first fossil trace of a parasite manipulating its host, but it’s not the oldest evidence for such a relationship. In 2008, another American group found a 105-million-year-old piece of amber containing a scale insect, with two Cordyceps stalks sticking out of its head. The war between insects and their Cordyceps nemeses is an ancient one indeed.

Reference: Biology Letters http://dx.doi.org/10.1098/rsbl.2010.0521
If the citation link isn’t working, read why here

How do you white balance your camera? Aim it at a piece of paper. How do you white balance an Earth-monitoring satellite? Aim it at a Turkish salt lake.

At least that’s the hope of scientists headed to southern Turkey to study a salt lake named Tuz Gölü (Turkish for “salt lake,” natch) later this month. During July and August, most of Lake Tuz evaporates into reflective white salt, making it perfect for satellite-calibration, the Committee on Earth Observation Satellites said, recently endorsing the spot as one of eight calibration sites.

Just as white balancing your camera is important to keep your friends from looking jaundiced, calibrating satellites makes sure that they can take accurate climate and coastal degradation measurements.

As Popular Science reports, the team led by the UK National Physical Laboratory will spend nine days at lake Tuz measuring the reflectance of test sites from a variety of angles. From above, several satellites will simultaneously take recordings of the white lake for comparison. The NPL hopes this will be the first step for an automated system “LandNET” using all eight sites.

Related content:
Discoblog: To Track Penguins, Scientists Use High-Tech Satellite Images of…Droppings
Discoblog: Extreme Intercontinental Ballistic Missile Makeover!
Discoblog: Dang, What Was That? Astronomers Wonder What Just Whizzed by Earth
Discoblog: Want to Monitor the Earth’s Magnetic Field? There’s an App for That.

Image: NASA

During the Pleistocene epoch animals thought big: It was the age of the megafauna, when creatures like the mammoth, an 8-foot-long beaver, and a hippopotamus-sized wombat walked the Earth. But these giants vanished one by one, and scientists have long wondered why.

Debate over what caused the megafauna to die out has raged for 150 years, since Darwin first spotted the remains of giant ground sloths in Chile. Possible causes have ranged from human influence to climate change in the past, even to a cataclysmic meteor strike. [BBC]

Now, a discovery on the South Pacific island nation of Vanuatu seems to have answered the question for at least one species. Researchers have turned up the bones of a giant land turtle in a dump used by the people who settled on the islands 3,000 years ago, and lead researcher Trevor Worthy says the evidence strongly suggests that the turtles were hunted into extinction.

Significantly, they have found mainly leg bones, but no head or tail remains, and only small fragments of shell. “This suggests very strongly that the animals were butchered somewhere other than in the village where we excavated them,” says Worthy. “They just cut them up and brought back the bits that had most meat on them.” [Australian Broadcasting Corporation]

All the species in this turtle family, the meiolaniids, were previously thought to have gone extinct 50,000 years ago, but the new find shows that at least one species (Meiolania damelipi) hung on in the isolated Pacific islands. The turtle’s death knell seems to have sounded when the Vanuatu islands were settled by the Lapita people around 3,000 years ago. The researchers carefully dissected the layers of rubbish in the Lapita dump, and say the last bones of M. damelipi were found in sediment layer dating to 2,800 years ago. This suggests that the turtles were wiped out in the course of a few hundred years, according to the paper published in the Proceedings of the National Academy of Sciences.

The Lapita would have hunted the slow-moving turtles, burned forests to clear cropland, and brought pigs and rats that ate their eggs. Worthy estimates that Vanuatu could have supported tens of thousands of M. damelipi, but in just 200 years they were gone. And if giant land turtles were on Vanuatu, they were likely found on other Pacific islands, and hunted into oblivion. [Wired]

Related Content:
80beats: Photos From the Gulf’s Great Sea Turtle Relocation
80beats: Turtle Shell Develops Through Embryonic Origami
80beats: A Clue to the Evolutionary Riddle of How the Turtle Got Its Shell
80beats: Scientist Smackdown: Were Giant Kangaroos Hunted Into Extinction?
80beats: Cavemen Found Innocent: Cave Bears Died From Cold, Not Spears

Image: Australian Museum