There has been considerable debate surrounding the origins of birds. Many believe that birds are descendants of dinosaurs, who were nearly wiped out about 65 million years ago (See my old post on periodic mass extinctions). But now scientists might have finally solved the puzzle once and for all:). A type of bone that female birds use as a calcium reserve for making eggshell has been found inside the fossilised thigh bone of a 68 million years old Tyrannosaurus Rex. The bone, called medullary bone, is densely rich in minerals and blood vessels, and is unique to ovulating female birds, who need the calcium to make the egg shells.

T. Rex tissue and bone (Courtesy: Pangea Institute)The calcium reserves are critical for female birds because they have strong but lightly-structured bones. Without medullary bone deposited in their marrow cavities, the calcium used for egg shells would come from their bones, giving them avian osteoporosis. Forming the shells depletes medullary bone, which in living birds remains depleted during brooding and until their next ovulation. The formation of the bone is triggered by an increase in estrogen levels.
The same distinctive structure of medullary bone were found in the T. Rex tissues. The T. Rex medullary bone is virtually identical in structure, orientation and even color, to that found in living emus and ostriches - large animals which are close to the evolutionary roots of modern birds. Living crocodiles do not have medullary bone, perhaps putting them farther in the evolutionary tree from dinosaurs than the birds:D:D.

Most of our energy requirements today are met by fossil fuels. These fuels were created in the interior of the Earth, when rotting ancient animal and plant remains got pressurized by the crust. As we use more and more of these fuels, it becomes harder and harder to mine/drill and transport and refine them for use. Some better way has to be found to meet our growing energy needs, and bio-fuel is one of them.

Fuel Cycle (Courtesy: PhysOrg)University of Wisconsin researchers have discovered a new way to make a diesel-like liquid fuel from carbohydrates commonly found in plants:). Published in the journal Science, Steenbock Professor James Dumesic and colleagues detail a four-phase catalytic reactor in which corn and other biomass-derived carbohydrates can be converted to sulfur-free liquid alkanes resulting in an ideal additive for diesel transportation fuel.
The process is very efficient, as the fuel contains 90% of the energy found in the carbohydrate and hydrogen feed. This process has twice the potential to create Ethanol (Ethyl Alcohol) than corn. Corn produces 1.1 units of energy for every unit of energy consumed. This process creates 2.2 units of energy for every unit of energy consumed in energy production:):).
The process works with a range of carbohydrates. As About 75% of the dry weight plants and trees is carbohydrates, a wider range of plants can be used to make bio-fuel.

Oppurtunity and Spirit are two semi-autonomous rovers that are currently surveying the Martian landscape. Built by NASA, Opportunity is the second of the two rovers of NASA's Mars Exploration Rover Mission. She landed successfully on Mars on January 24, 2004.
In addition to enormously valuable scientific work, both the rovers have also wowed us with lovely pictures (Spirit here, Oppurtunity here) from the red planet:). The latest image from Oppurtunity is a particularly poignant one, as the rover looks up in the sky, and finds its home planet, the planet it will never again be able to visit.

Hello Earth! (Courtesy: Mars Exploration Rover Mission)On its 449th martian day, or sol (April 29, 2005), NASA's Mars rover Opportunity woke up approximately an hour after sunset and took this picture of the fading twilight as the stars began to come out. Set against the fading red glow of the sky, the pale dot near the center of the picture is not a star, but a planet - Earth:):).
Earth appears elongated because it moved slightly during the 15-second exposures. The faintly blue light from the Earth combines with the reddish sky glow to give the pale white appearance.
I wonder when it will be us humans who will be able to take such pictures of Earth, from the surface of Mars.

In mathematics, Power Law is a relationship between two variables (say x and y) which follow a power pattern, e.g. y = ax^k, where a is a constant. According to physicists Olivier Bénichou and colleagues at the University of Paris and the Curie Institute, animals use power laws to minimize the time they spend searching for hidden objects:):). The study corroborates previous observations made by biologists, and could be used to speed up human searching.

Two-state search strategy (Courtesy: PhysicsWeb)Animals exhibit two different kinds of behavior while searching. In the first phase they move quickly on a single trajectory from one location to another. Then in the second phase they search the new location by moving around more slowly and randomly -- akin to molecules undergoing diffusion. They carry on this two-phase process until they find the object. Pet owners routinely see this type of behaviour in their dog, for example, when it looks for an object in the garden.
In order to minimize the search period, it seems that the time spent in the first phase is equal to the time spent in the second raised to a certain power, similar to the power law! This particular search technique might also be employed by us humans, for example, searching for a lost object or perhaps even a victim in an avalanche:):).

Our brains are amazing machines. Whenever we form a new memory, or learn a new trick, our brain forms new connections (synapses) between its cells. The synapses act as the storage (loosely speaking) of both the data (the memory) and the code (the technique behind the trick). Next time when we do the trick, this hard-wired information helps us perform much much better than the last time!
The way computers are currently made has a big drawback: once the microprocessors are made, the instructions inside are fixed. Software can be written to implement any code, but the software approach is almost always slower than a hardware-implemented code.

FPGA: The blocks can be switched on/off during reprogramming (Courtesy: Caltech)However, an experimental supercomputer made from hardware that can reconfigure itself to tackle different software problems is being built by researchers in Scotland :):). The system is being built by the EPCC (Edinburgh Parallel Computing Centre), and uses Field Programmable Gate Array (FPGA) chips instead of conventional microprocessors. A FPGA is a device that can be reprogrammed after it is manufactured, rather than having its programming fixed during the manufacturing. Therefore, it has some definite advantages over conventional microprocessors; the programming can be changed depending upon how the FPGA will be used.
The new computer incorporates 64 FPGA processing units and will run at 1 teraflop - one trillion mathematical operations per second. This is fairly modest by modern supercomputing standards, as the fastest machines can operate at hundreds of teraflops. This seems modest, But the Edinburgh system will be up to 100 times more energy efficient than a conventional supercomputer of equivalent computing power. The 64-node FPGA machine will also need only as much space as four conventional PCs, while a normal 1 teraflop supercomputer would fill a room:).
If this is successful, researchers will try to transfer several existing supercomputer programs onto the new hardware. If they work, then the supercomputer structure can be further scaled up for higher speeds.

The Andromeda galaxy is the most familiar of all the spiral galaxies in our sky. Wider and possibly brighter than our own Milky Way, Andromeda is about 2.4 to 2.9 million light years (one light year: the distance light travels in a year) away from the Solar System. It was previously thought that the Andromeda galaxy is 70,000 to 80,000 light years across, but now astronomers using the Keck II telescope in Hawaii have discovered that the galaxy is actually about 220,000 light years across. In comparison, our Milky Way is only about 100,000 light years across!

Andromeda Galaxy (Courtesy: NASA)Astronomers used the telescope to make new observations of the motions of stars in the most distant outskirts of the spiral galaxy. They found the movement of this sparse smattering of far-flung stars is actually synchronised with the rest of the galaxy's stars, rotating in an orderly way around its galactic centre. The stars surrounding Andromeda's spiral arms had been seen before, but astronomers had assumed they were captured fragments of other galaxies that would retain their own, essentially random, stellar motions.
The findings are hard to reconcile with current theories and computer models of galaxy formation, according to Rodrigo Ibata of the Observatoire Astronomique de Strasbourg, France, and another member of the research team. According to them, you just don't get giant rotating discs from the accretion of small galaxy fragments.
So back to rewriting the theories :):).

The invention of the electric light-bulb was a watershed event in human history. Since then, we have been using electric sources of light in our homes, offices, roads, and cars. However, electric lights are often bulky, produce a lot of heat, and do not last long. Over the last 40 years or so, tremendous progress has been made in solid-state devices, which include semiconductor-based microprocessor chips, sensors and Light-Emitting-Diodes (LEDs).
Scientists have long been working on boosting the light output of the LEDs, so that they can work as replacements for the more traditional incandescent light-bulbs. Finally, their work is slowly beginning to bear fruit :):).

Let there be (Solid-State) Light! (Courtesy: PhysOrg)In an article published in the journal Science, the researchers E. Fred Schubert and Jong Kyu Kim of Rensselaer Polytechnic Institute describe research currently under way to transform lighting into smart lighting, with benefits expected in such diverse fields as medicine, transportation, communications, imaging, and agriculture.
The applications include the ability to control basic light properties — including spectral power distribution, polarization, and color temperature — will allow smart light sources to adjust to specific environments and requirements and to undertake entirely new functions that are not possible with incandescent or fluorescent lighting.
There will be a lot of power savings: solid-state sources potentially could cut in half the 22 percent of electricity now consumed by lighting. Traffic lights using LEDs, for example, use only one-tenth the power of signals using incandescent lamps.
Other applications include automatic modification of light frequency, modulation and intensity to match the human circadian rhythm, light-based communication between cars on the road so as to minimize chances of collisions, better optical transmission lines, and improved resolution in microscopes.