Star Mira's comet-like tail stuns scientists

One can see the history of a dying star trailing in its wake, reports
Roger Highfield



A star that leaves a vast and turbulent comet-like tail of dust as it hurtles through the heavens has astronomers agog. An orbiting space telescope has spotted the amazingly long - and so far unique - tail stretching far behind Mira, named after the Latin word for "wonderful," which will provide astronomers with new insights into the life and death of stars, even how the building blocks of life were spread around the cosmos.Mira is a fast-moving older star, called a red giant, which sheds massive amounts of surface material as it rockets along. The object has fascinated astronomers for around four centuries because it is a rare example of a so called variable star, one that waxes and wanes in brightness. But it was only when Nasa's Galaxy Evolution Explorer (Galex) space telescope took a look at the object at ultraviolet wavelengths that are invisible to the human eye that it revealed what looked like a comet with a gargantuan tail to the team led by Prof Christopher Martin of Caltech, Pasadena. "After 400 years of study, Mira continues to astound," they conclude in the journal Nature.We never would have predicted a turbulent wake behind a star that glows only with ultraviolet light," said Seibert. "Survey missions like the Galaxy Evolution Explorer can provide many surprises."
http://www.telegraph.co.uk/earth/main.jhtml?view=DETAILS&grid=&xml=/earth/2007/08/16/scimira116.xml


'We have broken speed of light' : By Nic Fleming, Science Correspondent




A pair of German physicists claim to have broken the speed of light - an achievement that would undermine our entire understanding of space and time. According to Einstein's special theory of relativity, it would require an infinite amount of energy to propel an object at more than 186,000 miles per second. However, Dr Gunter Nimtz and Dr Alfons Stahlhofen, of the University of Koblenz, say they may have breached a key tenet of that theory.

The pair say they have conducted an experiment in which microwave photons - energetic packets of light - travelled "instantaneously" between a pair of prisms that had been moved up to 3ft apart.

Being able to travel faster than the speed of light would lead to a wide variety of bizarre consequences. For instance, an astronaut moving faster than it would theoretically arrive at a destination before leaving. The scientists were investigating a phenomenon called quantum tunnelling, which allows sub-atomic particles to break apparently unbreakable laws. Dr Nimtz told New Scientist magazine: "For the time being, this is the only violation of special relativity that I know of."


Alien life could be gas : Roger Highfield describes work that shows the quest for ET is too obsessed with carbon and water - Extraterrestrials could consist of living, breeding, floating clouds of interstellar dust, according to a study by an international team.


The traditional image of an extraterrestrial life form



As Dr McCoy often remarked in Star Trek, "it is life Jim, but not as we know it": the team sets out a new way that matter can replicate and evolve - two key properties of life - without depending on Earthly chemistry in the New Journal of Physics, hinting at more exotic possibilities for extraterrestrial life and a possible new explanation for the origin of life on Earth.
Life on Earth is composed of organic molecules, and can reproduce with the help of carbon chemistry and liquid water. But last month the US National Academy of Sciences warned that the "life as we know it" approach could easily miss something exotic and called on scientists to keep an open mind. Today's work sets out one unusual idea that particles of inorganic (non carbon) dust may take on a life of their own, going beyond the silicon-based life forms favoured by some science fiction stories. Under the right conditions, particles of inorganic dust can become organised into helical structures with lifelike properties, according to Prof Vadim Tsytovich of the General Physics Institute, Russian Academy of Science, in Moscow, who worked with colleagues there and at the Max-Planck Institute for Extraterrestrial Physics in Garching, Germany and the University of Sydney, Australia. The team studied the complex mixtures of inorganic materials in a plasma. Plasma is essentially the fourth state of matter beyond solid, liquid and gas, in which electrons are torn from atoms leaving behind a miasma of charged particles, and is present in plasma displays, fluorescent lamps and neon signs.Until now, physicists assumed that there could be little organisation in such a cloud of particles. However, Prof Tsytovich and his colleagues demonstrated that particles in a plasma can twist into corkscrew shapes, or helical structures. These twisted strands are themselves electronically charged and are attracted to each other. Not only do these helical strands interact in a counterintuitive way in which like can attract like, but they also undergo changes that are normally associated with biological molecules, such as DNA and proteins, say the researchers.They can, for instance, divide to form two copies of the original structure. These new structures can also interact to induce changes in their neighbours and they can even evolve into yet more structures as less stable ones break down, leaving behind only the fittest structures in the plasma. "These complex, self-organised plasma structures exhibit all the necessary properties to qualify them as candidates for inorganic living matter," says Prof Tsytovich, "they are autonomous, they reproduce and they evolve". The team says that future searches for extraterrestrials should take this work into account. Although the plasma conditions needed to form these helical structures are common in outer space, the team says that plasmas can also form under more down to earth conditions such as the point of a lightning strike. The researchers hint that perhaps an inorganic form of life emerged on the primordial Earth, which then acted as the template for the more familiar organic molecules we know today. The living plasma idea chimes with one put forward by Dr Graham Cairns-Smith at the University of Glasgow, who has argued for decades a simple intermediate step between dormant matter and organic life might be provided by the self-replication of clay crystals in solution. "Not being a plasma physicist I can not comment sensibly on the crucial details, but I am of course sympathetic with the idea of looking for things that can evolve but are not made of your standard 'molecules of life'", he remarks. "In connection with the origin of life what is needed first is not a stockpile of particular molecules, but things that can evolve somehow - and for long enough and far enough to do clever things, to look as if they had been designed. "The main interest in this new contribution is I think that new kinds of replicators would increase the number of places in the universe where prolonged evolutionary processes might take hold. And quite possibly a physics laboratory might be one of these places."