'Microbe led to mass extinction 251m years ago'

PTI | Dec 17, 2012, 05.02 AM IST

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LONDON: A humble microbe, instead of a devastating meteorite or a catastrophic volcanic eruption, wiped off over 90% of the species on Earth 251-million-years ago, scientists believe. According to prevailing theory, the mass extinction at the end of the Permian period was triggered by volcanic eruptions over a vast area of what is now Siberia, which led to a dramatic rise in greenhouse gas emissions.
However, according to Daniel Rothman of MIT, the scenario just doesn't fit the facts.
From his analysis of an end-Permian sediment sample from China, Rothman says carbon levels surged much too quickly for geological processes to be at work. Microbes can generate carbon compounds that fast.
As his group analysed the genome of Methanosarcina - a methanogen responsible for most of biogenic methane - they found that it gained this ability 231m years ago. Methanosarcina needs large amounts of nickel to produce methane quickly. The team discovered that nickel levels spiked 251m years ago in the sediment samples. This suggests Methanosarcina did trigger the extinction

Close call signals Earth needs an asteroid shield

Dec 17, 2012, 05.08 AM IST

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LONDON: Extensive monitoring systems and an Armageddon-style protocol is needed to save the Earth from a potentially hazardous asteroid, expected to fly by our planet in 2029, experts say. Actor Bruce Willis and his co-stars are given just 18 days to destroy a vast asteroid which threatens to wipe out life on Earth in the Hollywood movie "Armageddon" .

Scientists say the world must come up with a similar emergency plan after an asteroid whistled within a whisker of the Earth on Tuesday, only two days after it was first detected by astronomers , 'The Telegraph' reported. The Apophis asteroid , first detected in 2004, will come within 36,000 kilometres of Earth when it passes by and it can be seen with the naked eye as a burning point in the sky.

Scientists said although there is no chance of the asteroid colliding with Earth, there is an extremely small chance it could fall into a gravitational loop and come back to hit the planet in 2038.

The asteroid which passed by this week, known as 2012 XE54 measured just 36 metre across, but the last known asteroid of such a size to hit Earth wiped out an area of Russian forest the size of London in 1908.

Scientists are becoming increasingly concerned about the possible impact of asteroids measuring less than 1km across, which are not typically picked up by surveying programmes and could only be detected at very short notice.

Delegates from across the world will gather at the UN in February to come up with a framework for earlier detection of asteroids, and a plan of action if a collision is deemed possible.

Master computer controls universe?

PTI | Dec 17, 2012, 05.07 AM IST

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READ MORE Martin Savage|University of Washington|Professor

Physicists mull theory that humans may be mere pawns in a PC program

MELBOURNE: Scientists are conducting experiments to discover whether the universe exists within a Matrixstyle computer simulation created by super computers of the future.

The experiments being conducted by University of Washington could prove that we are merely pawns in some kind of larger computer game. However, it is unclear who created these super computers that may hypothetically power our existence.

"Imagine the situation where we get a big enough computer to simulate our universe, and we start such a simulation on our computers," said professor Martin Savage, a physicists working on the project. "If that simulation runs long enough, and have same laws as our universe, then something like our universe will emerge within that simulations, and the situation will repeat itself within each simulation," he said.

The current understanding of string theory indicates that there are 10,500 universes with different laws that determine the behaviour of particles within them, he said.

"So it is certainly true, that with enough computer resources, theorists would like to explore these universes ," he added.

Explaining how the experiment works, physicists claim that finite computer resources mean that space time is not continuous but set on a grid with a finite volume, designed to create maximum energy subatomic particles. The direction these particles flow in will depend on how they are ordered on the grid. They will be looking at the distribution of the highest energy cosmic rays in order to detect patterns that could suggest that universe is the creation of some futuristic computer technology.

And if it does turns out that we are mere players in some sort of computer programme, they suggested that there may be a way to mess with the program, and play with the minds of our creators. "One could imagine trying to figure out how to manipulate the code, communicate with the code and questions that appear weird to consider today," he said.