String Theory tied into Multiverses

BRIAN GREENE spent a good part of the last decade extolling the virtues of string theory. He dreamed that one day it would provide physicists with a theory of everything that would describe our universe - ours and ours alone. His bestselling book The Elegant Universe eloquently captured the quest for this ultimate theory.

"But the fly in the ointment was that string theory allowed for, in principle, many universes," says Greene, who is a theoretical physicist at Columbia University in New York. In other words, string theory seems equally capable of describing universes very different from ours. Greene hoped that something in the theory would eventually rule out most of the possibilities and single out one of these universes as the real one: ours.

So far, it hasn't - though not for any lack of trying. As a result, string theorists are beginning to accept that their ambitions for the theory may have been misguided. Perhaps our universe is not the only one after all. Maybe string theory has been right all along.

Greene, certainly, has had a change of heart. "You walk along a number of pathways in physics far enough and you bang into the possibility that we are one universe of many," he says. "So what do you do? You smack yourself in the head and say, 'Ah, maybe the universe is trying to tell me something.' I have personally undergone a sort of transformation, where I am very warm to this possibility of there being many universes, and that we are in the one where we can survive."

We keep banging into the possibility that we are one universe of many. Maybe that's telling us something

Vile trade: Bear Bile farming should be outlawed

JASPER is an Asiatic black bear, also known as a moon bear because of the yellow crescent on his chest. In 2000 he came to the Animals Asia Moon Bear Rescue Centre in Chengdu, China, from a bear farm.

When Jasper arrived his rescuers had to cut him out of a tiny "crush cage" that pinned him down so the farmer could extract lucrative bile from his gall bladder. Bear bile is used in traditional Chinese medicine and fetches a tidy price. In China, the wholesale price is around 4000 yuan (approximately $580) per kilogram; each bear produces up to 5 kilograms a year. But it comes at terrible cost.

Jasper spent 15 years in his cage. Other bears spend up to 25 years in cages no bigger than their bodies, barely able to move. Bears are milked for bile twice a day. In China, farmers use a crude catheter inserted into the gall bladder or a permanently open wound. In Vietnam, they use long hypodermic needles.

Over the past 10 years, Animals Asia has rescued 260 bears from Chinese bear farms. These are the lucky ones. The official number of farmed bears in China is 7000, but Animals Asia fears the real figure is closer to 10,000.

NEO: 3Km wide Asteroid in contra orbit - potential impact threat

The newly discovered asteroid 2009 HC82 travels on an orbit that is tilted by 155° with respect to the orbital plane of the planets, which means it travels in the opposite direction (Illustration: NASA/JPL)

The discovery of a 2- to 3-kilometre-wide asteroid in an orbit that goes backwards has set astronomers scratching their heads. It comes closer to Earth than any other object in a 'retrograde' orbit, and astronomers think they should have spotted it before.

The object, called 2009 HC82, was discovered by the Catalina Sky Survey in Arizona on the morning of 29 April.

From observations of its position by five different groups, Sonia Keys of the International Astronomical Union's Minor Planet Center calculated it orbits the sun every 3.39 years on a path that ventures within 3.5 million km of the Earth's orbit. Combined with its size, that makes 2009 HC82 a potentially hazardous asteroid.

HC82 a potentially hazardous asteroid.

What's really unusual is that the calculated orbit is inclined 155° to the plane of the Earth's orbit. That means that as it orbits the Sun, it actually travels backwards compared to the planets. It is only the 20^th asteroid known in a retrograde orbit, a very rare group. None of the others comes as close to the Earth.

The retrograde orbit of this asteroid will greatly increase the 'speed at impact' of this object, colliding with the Earth

The retrograde orbit of this asteroid will greatly increase the 'speed at impact' of this object and its potential for major damage. This is because both the Earth and HC82 will be travelling towards each other at high speed, like two trains heading towards each other on the same track.

The power of thought

Swine flu: The predictable pandemic

THE swine flu virus has been a serious pandemic threat for years but research into its potential has been neglected compared with other kinds of flu.

New cases are being reported far from the original outbreak in Mexico. The clusters of milder infections in the US suggest the virus is spreading readily among people. The US Centers for Disease Control and Prevention (CDC) says this strain is so different from existing human flu viruses that most people have no immunity to it. Despite the claims, there are no existing vaccines.

All this means the virus could go pandemic. Or it might not: it could be self-limiting. If the virus spreads less readily than is feared, it might not be able to maintain itself in the human population and could fizzle out.

Vaccines such as Tamiflu (Oseltamivir) and Relenza (Zanamivir), are not totally effective against viral strains

The WHO is only now taking measures to produce an effective vaccine against the new H1N1 virus. This will between four to six months to develop, test and produce in sufficient numbers.

Spoke-like patterns on Mercury

Rembrandt, the second-largest impact basin on Mercury, was discovered during the Messenger spacecraft's second flyby in October 2008. Researchers are now puzzling over features found near its centre (pictured), which show a spoke-like pattern of ridges and troughs that is reportedly unlike anything else in the solar system (Image: NASA/JHUAPL/Smithsonian/Carnegie Institution of Washington)

Dancing Parrots