SCIENCE FORUM

Alternate universes: fairy tale, sci-fi or reality?

On the 50th anniversary of the "many worlds" theory, Rashida Ahmad reminds us that reality can be stranger than fiction

Literature, art, philosophy and our everyday lives--from daydreams to weighing up pros and cons--are filled with examples of imagined or alternate realities. Though science fiction, from the middle of the 20th century and on, really took the concept of alternate realities and parallel universes to its heart. The strange and spooky dimension where things are 'the same but not the same' has become a sci-fi staple.

Indeed, science fiction and other popular science media have so inured us to the fantastic in science, that once-radical concepts--such as wormholes, artificial intelligence, the possibility of time travel and parallel universes--have become accepted and familiar territory.

This year marks the 50th anniversary of the 'many worlds' theory, which Star Trek et al have made their own. And it is perhaps strange for many of us to look back and realise how outlandish the original proposal was in its day.

In 1957, a PhD student took quantum physics at face value and imagined what it really meant. Hugh Everett III, who went on to become a renowned nuclear physicist, proposed the "relative state formulation" in a branch of quantum physics known as wave function theory. He aimed to resolve the paradoxes of quantum theory by allowing every possible outcome to every event to exist in its own world.

Everett's formulation was later popularised and renamed "many worlds" by physicists in the 1960s and '70s. Although too bizarre for most physicists of the 1950s, the many worlds theory now has its followers

According to quantum theorists, it's possible that at every possible point in time and space a quantum universe branches off from our own and develops independently. In this model every possible world exists. Some physicists hypothesise that since there are an infinite number of these quantum worlds, there must exist somewhere a near carbon copy of our universe. Indeed, there may be a universe that's identical to this one but for the fact that the sky is purple.

Moreover, say adherents of the many worlds theory, accepting quantum physics to be universally true means that you should also believe in the existence--not just the possibility--of parallel universes. The history of the physical universe, which prior to many worlds was viewed as a single "world-line", is in fact a many-branched tree where every possible branch is realised.

Is it still possible to view such a theory as radical, fantastic or bizzare today? Or indeed did the formulation of "many worlds" just mark a point where science was catching up with art, philosophy and the human imagination?

The answer to that may be debatable, just as science may never prove whether many worlds do exist. But it is perhaps worth bearing in mind, the next time you watch the leading man battle evil in a parallel universe or daydream about what you would do if you were a millionaire, alternate realities may well be stranger than science fictions.

A question of colour
Europeans only started acquiring pale skin between 6,000 and 12,000 years ago, according to recent studies in the US. This challenges the more common theory that Europeans became light-coloured soon after migrating to northern latitudes about 40,000 years ago. The genetic origins of skin colour had been a mystery for biologists until a recently discovered gene was found to cause pale skin in Europeans but not in Asians. The DNA and mutation rate of this gene suggests the evolution of light skin occurred long after the arrival of modern humans in Europe. The implication is that our European cousins were brown skinned for tens of thousands of years. The change from hunting and gathering to farming around 6,000 years ago may mean that a combination of fewer hours of sunlight and fewer natural sources of vitamin D may be responsible for the permanent change in skin colour.

Fat friendly

Biryani and lack of exercise may not be the only reasons for gaining weight. A new study on obesity in the U.S finds that having an overweight friend makes a person 57 percent more likely to develop a bulging waistline too. The effect was strongest for close friends but also occurred if friends of friends--or even their friends--gained weight, suggesting tht obesity spreads as a kind of social contagion, the same phenomenon that appears to explain fads from diets to Harry Potter. Researchers say the contagion effect may occur because we mimic or unconsciously adopt the behaviour of people we like and that it should be taken into account when trying to counteract obesity.

Better immunisations against computer viruses

Maverick programmers who design malicious software, or malware, that damages, takes over or steals data from computers are locked in an arms race with companies that make anti-virus software to prevent and fix malware damage. Letting computer viruses loose on a 'quarantined' computer and recording their pattern of activity could lead to a better way of spotting them in the 'wild.' A prototype system developed at the University of Michigan uses the 'fingerprint' of virus activity to identify them more effectively than existing antivirus software. Such a system should lead antivirus programmes to create to better immunisation for computers against the most lethal viruses.

The proof is in the Chilean chicken

The discovery of chicken bones with Polynesian DNA at an archaeological site in Chile has added physical evidence to the controversial theory that ancient seafarers from the south Pacific visited the New World long before Columbus. When the Spanish conquistadors first landed in the Americas in the 16th century they found the Incas making use of chickens in daily and ritual life. Chickens were first domesticated in Asia, but the lack of their archaeological evidence in north America suggests they were not carried by migrating people over the prehistoric land bridge that connected Siberia to Alaska. Radiocarbon analysis dates the Chilean bones to the 14th century, before the Europeans arrived. Moreover the DNA from these bones matches that of chickens excavated from sites in Tonga and Samoa.

Yawning may cool the brain

Yawning is something most of us associate with tiredness or boredom. But instead of switching off, our brains may actually become more attentive through yawning. According to psychologists at the State University of New York at Albany, we yawn to boost blood flow and 'chill the brain.' The theory may also explain why yawns are contagious. If yawning is triggered by empathic mechanisms, it can function to maintain group vigilance. In other words, contagious yawning evolved to help raise the attentiveness of a whole family or tribe.

Dancing atoms may make quantum computers

Suspended in laser light, atoms can be made to pair up and 'dance.' These dancing pairs may one day be the building blocks of enormously powerful quantum computers capable of solving in seconds what today's fastest machines take years to compute, say researchers with the U.S. National Institute of Standards and Technology or NIST. So far, all the pairs are dancing to the same tune. To be useful in a quantum computer, the NIST physicists will need to figure out how to get different pairs to dance and spin independent of the neighboring atom pairs. The NIST team is one of several around the world working to develop a system that could support quantum computing.

Rashida Ahmad is Contributing Editor at Forum