The first close-range, low-frequency recordings of volcanic eruptions have revealed a surprising similarity to the noise made by jet engines. The finding may provide clues to what happens prior to volcanic explosions.

Hear an infrasound recording of an eruption at Mount St Helens, speeded up 200x.

Robin Matoza of the University of California, San Diego, and colleagues measured infrasonic signals from volcanic eruptions around the globe, getting as near to them as 13 kilometres - relatively close for these sorts of measurements. This was the first time that infrasonic signals from very large eruptions had been measured at relatively close range.

In the natural world, DNA provides a kind of blueprint that directs a complex molecular dance which culminates in the creation of a much larger, more complex object - be it bacterium or elephant.

Now, using a method known as "DNA origami", chemists have managed a similar if much simplified version, creating artificial DNA that can also build itself into larger, more complex structures.

DNA with those capabilities could provide new ways of manufacturing on a small scale - for example, in the field of nanoelectronics - or performing calculations.

The new method has been developed by Paul Rothemund and Erik Winfree, both at the California Institute of Technology in Pasadena.

Today the John Templeton Foundation announced the winner of the annual Templeton Prize of a colossal £1 million ($1.4 million), the largest annual prize in the world.

This year it goes to French physicist and philosopher of science Bernard d'Espagnat for his "studies into the concept of reality". D'Espagnat, 87, is a professor emeritus of theoretical physics at the University of Paris-Sud, and is known for his work on quantum mechanics. The award will be presented to him by the Duke of Edinburgh at Buckingham Palace on 5 May.

D'Espagnat boasts an impressive scientific pedigree, having worked with Nobel laureates Louis de Broglie, Enrico Fermi and Niels Bohr. De Broglie was his thesis advisor; he served as a research assistant to Fermi; and he worked at CERN when it was still in Copenhagen under the direction of Bohr. He also served as a visiting professor at the University of Texas, Austin, at the invitation of the legendary physicist John Wheeler. But what has he done that's worth £1 million?

The thrust of d'Espagnat's work was on experimental tests of Bell's theorem. The theorem states that either quantum mechanics is a complete description of the world or that if there is some reality beneath quantum mechanics, it must be nonlocal - that is, things can influence one another instantaneously regardless of how much space stretches between them, violating Einstein's insistence that nothing can travel faster than the speed of light.

There is nothing certain in this world, US founding father Benjamin Franklin once wrote, except death and taxes. As a scientist, he might have added a third inescapable force: gravity, the unseen hand that keeps our feet on the ground.

Gravity is the universal force. Not only does it stop us getting above ourselves, it keeps Earth orbiting around the sun, our sun swinging around the centre of the Milky Way, the Milky Way in a merry dance around its neighbours, and so on upwards. It is actually the weakest of nature's four forces, but whereas the other three - electromagnetism and the strong and weak nuclear forces - unleash their full strength only at the scales of atoms and particles, gravity conserves its power to trump all comers in the cosmos at large. Just take any two things that have mass, and whatever their size, wherever they are, they will feel gravity's grasp in exactly the same way.

Or will they? Justin Khoury, now of the University of Pennsylvania in Philadelphia, and his colleagues Niayesh Afshordi and Ghazal Geshnizjani of the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, are not so sure. They have listed a series of cosmological observations that cannot readily be explained with a one-size-fits-all gravity. None of these effects on its own, they stress, necessarily indicates anything amiss. But intriguingly, all of them melt away if you make just one assumption, albeit a controversial one: that how gravity works depends on the scale on which you look at it.

U.S. scientists say they have, for the first time, changed high frequency sounds into light by reversing a process that converts electrical signals to sound.

The Lawrence Livermore National Laboratory researchers said their new tool enhances the way computer chips, LEDs and transistors are build.

Commonly used piezo-electric speakers, such as those found in a cell phone, operate at low frequencies that human ears can hear, the scientists from LLNL and the Nitronex Corp. said. But by reversing that process, lead researchers Michael Armstrong, Evan Reed and Mike Howard used a very high frequency sound wave -- about 100 million times higher frequency than what humans can hear -- to generate light.

Using NASA's Spitzer Space Telescope, researchers have found evidence suggesting that stars rich in carbon complex molecules may form at the center of our Milky Way galaxy.

This discovery is significant because it adds to our knowledge of how stars form heavy elements - like oxygen, carbon and iron - and then blow them out across the universe, making it possible for life to develop.

Astronomers have long been baffled by a strange phenomenon: Why have their telescopes never detected carbon-rich stars at the center of our galaxy even though they have found these stars in other places? Now, by using Spitzer's powerful infrared detectors, a research team has found the elusive carbon stars in the galactic center.

The discovery in common brewer's yeast of a new, infectious, misfolded protein -- or prion -- by University of Illinois at Chicago molecular biologists raises new questions about the roles played by these curious molecules, often associated with degenerative brain diseases like "mad cow" and its human counterpart, Creutzfeldt-Jakob. Susan Liebman, distinguished university professor of biological sciences, and postdoctoral research associate Basant Patel propagated the new prion from a normal yeast protein called Cyc8. They note that like the Cyc8 protein, the prion of Cyc8 can affect the expression of a large number of yeast genes.

"We know this prion turns on the expression of genes but we don't know if the prion forms naturally," said Liebman. "If it were to form, it would have this effect. But whether it happens out in the wild all the time, we don't know."

Learn more about: basal ganglia dopaminergic neurons pennsylvania researchers substantia nigra unexpected rewards university of pennsylvania

The human brain's sensitivity to unexpected outcomes plays a fundamental role in the ability to adapt and learn new behaviors, according to a new study by a team of psychologists and neuroscientists from the University of Pennsylvania. Using a computer-based card game and microelectrodes to observe neuronal activity of the brain, the Penn study, published this week in the journal Science, suggests that neurons in the human substantia nigra, or SN, play a central role in reward-based learning, modulating learning based on the discrepancy between the expected and the realized outcome.

"This is the first study to directly record neural activity underlying this learning process in humans, confirming the hypothesized role of the basal ganglia, which includes the SN, in models of reinforcement including learning, addiction and other disorders involving reward-seeking behavior," said lead author Kareem Zaghloul, postdoctoral fellow in neurosurgery at Penn's School off Medicine. "By responding to unexpected financial rewards, these cells encode information that seems to help participants maximize reward in the probabilistic learning task."

Sometimes objects in the sky that appear strange, or different from normal, have a story to tell and prove scientifically very rewarding. This was the idea behind Halton Arp's catalogue of Peculiar Galaxies that appeared in the 1960s. One of the oddballs listed there is Arp 261, which has now been imaged in more detail than ever before using the FORS2 instrument on ESO's Very Large Telescope. The image proves to contain several surprises. Arp 261 lies about 70 million light-years distant in the constellation of Libra, the Scales. Its chaotic and very unusual structure is created by the interaction of two galaxies that are engaged in a slow motion, but highly disruptive close encounter. Although individual stars are very unlikely to collide in such an event, the huge clouds of gas and dust certainly do crash into each other at high speed, leading to the formation of bright new clusters of very hot stars that are clearly seen in the picture. The paths of the existing stars in the galaxies are also dramatically disrupted, creating the faint swirls extending to the upper left and lower right of the image. Both interacting galaxies were probably dwarfs not unlike the Magellanic Clouds orbiting our own galaxy.

The images used to create this picture were not actually taken to study the interacting galaxies at all, but to investigate the properties of the inconspicuous object just to the right of the brightest part of Arp 261 and close to the centre of the image. This is an unusual exploding star, called SN 1995N, that is thought to be the result of the final collapse of a massive star at the end of its life, a so-called core collapse supernova. SN 1995N is unusual because it has faded very slowly - and still shows clearly on this image more than seven years after the explosion took place! It is also one of the few supernovae to have been observed to emit X-rays. It is thought that these unusual characteristics are a result of the exploding star being in a dense region of space so that the material blasted out from the supernova plows into it and creates X-rays.

Seven astronauts raced to the international space station aboard space shuttle Discovery on Monday, while NASA debated whether the orbiting outpost will need to move aside to dodge part of an old Soviet satellite.

Space station astronauts had a close call last week with a small piece of orbiting junk, and NASA said Monday that debris from a satellite that broke apart in 1981 could come within about half a mile of the station early Tuesday.

NASA will decide later Monday whether to fire the space station's engines to nudge the complex out of the path of the debris.