From time to time, the planet Earth suffered mass extinctions. The last big one happened about 65 million years ago (Cretaceous ends, Paleogene begins) and wiped out the dinosaurs, and many other species. But the biggest one happened about 250 million years ago, and the event marks the transition from the Permian geological period to the Triassic. Roughly 90 percent of all marine life died, as well as nearly three-quarters of all land plants and animals! Now a new study finds that this great dying might have caused a lack of oxygen that left animals gasping for air.

Pangea Break-up (Courtesy: USGS)Back then, the Earth's continents were glued as a single large super-continent, called the Pangea. The reason behind the Great Dying is not known, and different hypotheses have been put forward (asteroid impact, global warming, supervolcanoes). The Lack-of-Oxygen scenario (put forward by Raymond Huey and Peter Ward of the University of Washington) might just be what really happened.
Oxygen currently makes up about 21% of our atmosphere. In the early Permian period it was 30%, from where it fell to 16% during the Great Dying, and to 12% after that. Such low levels of oxygen meant that animals at sea level breathed air similar to that at the top of a 17,400-foot mountain today! At higher elevations, the oxygen content would be still lower. Effectively, this would restrict the movements of the animals living during that time. Populations of animals might be fragmented, leading to their speedy demise.
Even though just the lack of oxygen might not be the sole reason, it could be a large factor in what happened. Perhaps the living kingdom suffered a double whammy, a lack of oxygen, coupled with some other major event that precipitated the mass extinction.

In the futuristic movie Minority Report, the lead character (portrayed by Tom Cruise) manipulates on-screen images by using a gloved hand. A video-camera picks up the 3D hand-motions, and the computer translates the motions into actions on the display. Now researchers from the defence company Raytheon have come up with a prototype that does exactly that. They have even employed John Underkoffler, the researcher who proposed the interface to the makers of the film!

Talk to the hand! (Courtesy: Raytheon)Current user interfaces (keyboard, mouse) work in a 2D world, which limits their applications. Even supposedly 3D interfaces (trackballs, game-controllers) are not truly 3D, as you need more than one control for accurate 3D navigation. The system in Raytheon allows the user to wear a a pair of reflective gloves and manipulate images projected on a panoramic screen. A camera takes live pictures, and the computer processes the images to translate into motion on the screen.
Such technology can be used to sort through large volumes of data (for example, satellite imagery, intelligence data), and also might help doctors to perform virtual surgery. It also has huge potential in gaming and virtual reality-based applications.

Scientists at the Australian National University might have found one of the earliest stars to have formed in the Universe. The star, called HE 1327-2326 has the lowest level of Iron found in any star, and was discovered by Anna Frebel and her team (findings published in the journal Nature). Since heavier elements such as Iron are supposed to have (mostly) formed through supernovae explosions, higher concentrations of Iron are found in successive generation of stars. This star was observed using the Japanese Subaru telescope (8 meters), and found to be twice as iron poor as the previous record holder.

The first star (Courtesy: STSCI)The Japanese telescope has other impressive observations under its belt; it recently found one of the most distant galaxies. This new star-find is crucially important, as it provides the crucial evidence of the time when the very first stars formed after the Big Bang. The star will be used to trace the development of elements in the early Universe, to see if the current theoretical models regarding creation of elements are accurate. Such models are often derived using particle accelerator experiments, and it is awe-inspiring to see the domain of the large (stars, galaxies) and of the small (fundamental particles) come together in this way :).
The star also has abnormally high levels of Carbon, Strontium, and Nitrogen. Another interesting feature is that little (if any) Lithium is found in the star. This is higly unusual, as Lithium is one of the lightest elements (Atomic Number = 3), and relatively newer stars have more Lithium content, and follow theoretical models closely.
Explanations? It could very well be that the ancient cloud of gas that formed the star was rich in elements heavier than Hydrogen, Helium, and Lithium. But it is very unlikely; the more likely scenario is that the star was formed relatively early, and is one of the true first generation stars.

Due to a lack of atmosphere, the temperature at the surface of the moon varies wildly, depending mostly on the day-night cycle. In the day, the temperature of the Moon averages 107°C, although it rises as high as 123°C. The night cools the surface to an average of -153°C, or -233°C in the permanently shaded South Polar Basin. A typical non-polar minimum temperature is -181°C (at the Apollo 15 site). Regions with wild variations in temperature are not preferable for designed a lunar base, where humans have to be able to live round-the-clock, and thus spots with more habitable climates have to be located. Now, scientists have perhaps found such a perfect spot at the lunar North Pole.

Lunar Illumination Map (Courtesy: MSNBC)Any such region should have permanent sunlight, so as to allow a) round-the-clock solar energy, and b) a near-constant temperature. Such spots can only be found near the lunar poles; in particular, scientists have identified that the best spot to settle on the moon may be on the northern rim of Peary crater, close to the lunar North Pole. The analysis, to be published in the April 14 issue of the journal Nature, is based on 53 images from the spacecraft Clementine, which orbited the moon for 71 days in 1994.
Unlike Earth, whose extreme tilt causes seasons, the Moon's rotational axis is almost perfectly upright, deviating just 1.5 percent from the main plane of the solar system that extends outward from the Sun's belly. On Earth, summer means constant sunlight at the North Pole, and winter plunges the Arctic into permanent darkness. But on the moon, theorists have long suspected there might be high points from which the sun is always visible.
The southern pole also has such sweet spots. However, the northern pole has more water, and that is a critical point that tilted the decision in favor of the northern spot.

Bose-Einstein Condensate (BEC) is a super-fluid phase formed by atoms cooled to very close to Absolute Zero (about -273.15°C). At this temperature, the atoms get into a single quantum state (essentially behaving as one super-atom), and exhibit some really interesting phenomena. Now, Harvard University scientists (Lene Hau and group) have shown that these ultra-cold atoms can essentially 'freeze' and 'control' light, and form a processing unit of an optical computer :):). Optical computers would transport information ten times faster than traditional electronic devices (essentially at the speed of light), thereby smashing the intrinsic speed limit of silicon technology.

Stopped Light! (Courtesy: Hau's Lab)Professor Hau's group was previously able to slow down the speed of light (299,792,458 meters/second, or 186,000 miles/second, in vacuum) to about the speed of a bicycle, by using a cloud of BEC composed of sodium atoms. The same apparatus now is able to stop the motion of light alltogether! One applications of this could be in memory storage for a future generation of optical computers.
But the really striking discovery is that such frozen light can be used to do 'computations'!! The amplitude and phase of 'moving' light is smeared out over a distance (imagine a ripple on a lake). However, these characteristics are essentially frozen in stationary light, and thus can be used to a) store information (act as memory), and b) combined with amplitude/phase from other light particles (photons) to form rudimentary computational units (e.g. for addition and subtraction: just as two ripples sometimes form a bigger ripple when they cross each other). Combining many such units could one day lead to a true optical computer.
In addition to the beauty of such a structure, such optical processors will far exceed the capabilities of the electronic computers of today. Photons are much smaller than electrons, and carry no charge. Hence they can be packed in a much smaller space, thus perhaps leading to a higher density of such computational units than can be achieved in modern computers.
Hopefully, this century (and next) will belong to the quantum and the optical comptuers, just as the last one saw the rise of their electronic brethren :):).

Scientists at the University of Illinois at Urbana-Champaign have developed the fastest transistor (a typical computer processor contains millions of these). Working at the blinding speed of 604GHz, the new device was built from compounds called Indium Phosphide and Indium Gallium Arsenide that were designed to reduce data-transit time and improve density. The same group established an earlier record in 2003, when they made a transistor work at 509GHz (by breaking their own records of 452GHz and 382GHz).

Light emitting transistor (Courtesy: UIUC)The research was funded by the U.S. military through a $5.9 million DARPA grant. The results were published by Milton Feng and his student Walid Hafez in the journal Applied Physics Letters.
This new transistor paves the way to the creation of tera-hertz (1000+ GHz) devices. The researchers employed a technique known as Pseudomorphic grading, in which selective doping of the base, collector and emitter regions of the transistor results in a lower band-gap, and therefore, higher speed.
Once wired by the thousands into circuits, this faster transistor could improve the quality and battery life of high-frequency electronics like cell phones. This work can also lead to faster and more energy efficient computers and communication networks: the same group created the world's first light emitting transistor in 2003, which when combined with this transistor, can make high-speed (Tera-Hertz) fiber-optic communications possible.

Solar flares are the most enigmatic of the displays that the Sun puts up for us mortals. Huge wisps of gas erupt from the solar surface, unleashing impressive displays of electro-magnetic storms, that often knock out earth-orbiting satellites, and interfere with our television broadcasts. But the processes that cause such flares are largely a mystery. Now scientists from Mullard Space Science Laboratory (MSSL) and University College London have discovered some new evidence that points to the cataclysmic events that trigger a solar flare and the mechanisms that drive its subsequent evolution.

A Solar Flare (Courtesy: SOHO)A really large solar flare was observed by the ESA-NASA SOHO spacecraft on 15 July 2002. A detailed analysis of the flare, just published by Louise Harra of MSSL, shows that the flare was a complex event with three eruptions -each one triggering the next one like a domino effect. The solar flare's explosive power was 5,000 million times greater than an atomic bomb, hurling a billion tonnes of hot gas towards the Earth at speeds of around half a million miles an hour :):).
The analysis showed that the explosion was triggered by the sudden emergence of plasma from below the Sun's surface, close to an existing region of strong magnetic field. The two magnetic fields collided, releasing tremendous energy in form of the flare. This contradicts the current understanding of flare creation, which asserts that flares form when a magnetic line entangles and reconnects in the corona.
Now, it looks like flares can also occur when magnetic lines of force collide with each other. Since scientists can observe the growth of these lines of force on the surface of the Sun (by tracking the radiation emitted by the charged particles going around these lines), they should be able to predict when two lines will collide. This will allow scientists to predict the occurrence of such flares.
Such predictions are important, since a large flare can destroy expensive satellites, and can also be a hazard for astronauts on the International Space Station. By predicting the flares before they occur, they will have a much greater chance of hiding when the flare reaches the Earth.