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SCIENCE UPDATE: Duplicate universe, trapped in a computer
SCIENTISTS have recreated a vast segment of the universe inside a computer and written a brief history of time, black holes and galaxy formation.
The Millennium Simulation — the biggest exercise of its kind — required 25 million megabytes of memory. But it tracked the 14bn-year history of creation in months and now offers a tool to explore mysterious events in galaxies far away and long ago.
“It is the biggest thing we have ever done,” said Carlos Frenk of the University of Durham. “For the first time we have a replica universe which looks just like the real one. So we can now for the first time begin to experiment with the universe.”
The British, German, US and Canadian astrophysicists in the Virgo consortium, led by Volker Springel of the Max Planck Institute in Germany, reported in Nature recently that they already knew the so-called “initial conditions” of the universe. These were imprinted in the cosmic microwave background radiation, the embers of the Big Bang, when the universe was only 400,000 years old.
In the last few years, they have been able to determine that all the stars, galaxies, black holes and their radiation add up to a trifling 5 per cent of the universe. Around a quarter of creation is mysterious stuff called cold dark matter. The other 70 per cent is now known to be the even more baffling “dark energy”.
Prof Frenk said: “We programmed the biggest computer in Europe with these ingredients and the laws of physics and we just let it compute a universe. We let it churn away for a month and at the end we got this beautiful universe, which for all intents and purposes looks like the real thing.
“We are now going to study it in detail.” The simulated universe represents a cube of creation with sides that measure 2bn light years. It is home to 20m galaxies, large and small.
It has been designed to answer questions about the past, but it offers the tantalizing opportunity to fast-forward in time to the slow death of the galaxies, billions of years from now. — Dawn/The Guardian News Service
Power cables linked to cancer
Children living near high-voltage power lines are substantially more likely to develop leukaemia, researchers from Oxford University and the national electricity grid reported recently in the British Medical Journal.
Those living within 200 metres of the overhead cables were 70 per cent more likely to develop the disease than similar children living more than 600 metres away. And those living between 200 and 600 metres away had a 20 per cent increased risk.
The results were based on an eight-year investigation into the circumstances of the 9,700 children who developed leukaemia in England and Wales between 1962 and 1995. The researchers found 64 of the children lived at birth within 200 metres of a power line and 258 lived between 200 and 600 metres away. The statistics suggested that living in close proximity to a power line might be linked in some way to leukaemia.
But Gerald Draper, leader of the study team from the Oxford childhood cancer research group, said the research had not found any scientifically valid causal link. Earlier research showed that high-voltage lines could give out a weak magnetic field extending for about 60 metres. This was equivalent to about 1 per cent of the earth’s existing magnetic field.
It could not explain why the risk of leukaemia was as great for a child living nearly 200 metres from a line as for one living directly beneath one. — Dawn/The Guardian News Service
Missing tigers of India
The apparent disappearance of tigers from one of their last remaining Asian enclaves has fueled a growing conservation scandal in India. Wildlife officials are concerned about the reported elimination of tigers in the last year in the Sariska Wildlife Sanctuary in the desert state of Rajasthan.
The demise of the park’s 16 to 18 tigers could signal trouble in other sanctuaries. Indian Prime Minister Manmohan Singh has ordered a police investigation into the disappearance and has appointed a task force of forest officials, wildlife experts and community leaders to evaluate the country’s dwindling tiger population.
He also banned the practice of giving tigers to foreign dignitaries and established a wildlife crime prevention bureau. India’s tiger population has shrunk from an estimated 40,000 a century ago to about 3,700 this year, according to the government census. — Dawn/LAT-WP News Service (c) Los Angeles Times
Journey to the centre of Earth
Japanese scientists are to explore the centre of the Earth. Using a giant drill ship to be launched soon, the researchers aim to be the first to punch a hole through the rocky crust that covers our planet and to reach the mantle below.
The team wants to retrieve samples from the mantle, six miles down, to learn more about what triggers undersea earthquakes. They hope to study the deep rocks and mud for records of past climate change and to see if the deepest regions of Earth could harbour life.
Asahiko Taira, director general of the Centre for Deep Earth Exploration in Yokohama, said: “One of the main purposes of doing this is finding deep bacteria within the ocean crust and upper mantle. We believe there has to be life there. It’s the same mission as searching for life on Mars.”
The 57,500-tonne drill ship Chikyu is being prepared in the southern port of Nagasaki. Two-thirds the length of the Titanic, it is fitted with technology borrowed from the oil industry that will allow it to bore through 7,000 metres of crust below the seabed while floating in 2,500 metres of water — requiring a drill pipe 25 times the height of the Empire State building. The deepest hole drilled through the seabed so far reached 2,111 metres. — Dawn/The Guardian News Service
Super-predator
Fossil records show that around every 26m years, a mass extinction occurs on Earth, wiping out millions of species and leaving only a few hardy survivors. These regular catastrophic culls have often been blamed on meteorite bombardments.
But now a paper in Physical Review suggests that the cause could lie much closer to home. Adam Lipowski, a Polish physicist, has developed a computer model which shows that periodic mass extinctions could be caused by the evolution of a “super-predator”. — Dawn/The Guardian News Service
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