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Fossils prove life began more than 3.4bn years ago
Earth’s oldest fossils, found by researchers in Australia, are seen in this photograph released in London by Oxford University. Photo: Reuters Higgs boson may be a mirage
Trends
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Fossils prove life began more than 3.4bn years ago The fossilised remains of the oldest known lifeforms on the Earth have been discovered in samples of rock collected near a remote watering hole in the middle of the Australian Outback. Scientists said the microscopic fossils belonged to primitive bacteria that lived more than 3.4 billion years ago, when the Earth had emerged from a period when it was probably too hostile for life. The primitive microbes used sulphur instead of oxygen to generate energy from food and, the scientists said, they may be the closest that science will ever get to the mysterious origin of life on the Earth. The fossils were found in rocks that were originally formed in shallow seas near a coastline and suggest that beaches may have been the key habitat where the Earth’s first lifeforms thrived, said David Wacey, of the University of Western Australia. “The environment in which the microfossils were found is important-— it extends the record of life in shoreline or beach-like environments by about 200 million years. This suggests that beaches could have been the setting for the origin of life itself,” he said. “The discovery gives good solid evidence for life over 3.4 billion years ago. It confirms there were bacteria at this time, living without oxygen.” The Earth is estimated to be about 4.5 billion years old but the planet’s hostile, meteorite-bombarded environment is thought to have been too inhospitable for life to get going until about 3.8 billion years ago. Previous studies have indicated the presence of similar microfossils in 3.5 billion-year-old rocks but these claims have been disputed. The latest microfossils have been subjected to an exhaustive series of tests which have confirmed that they were once living cells, not merely the product of non-living chemical reactions. They were discovered in rock that was sandwiched between layers from two well-dated volcanic eruptions, which narrowed the fossils’ date of origin to within a few tens of millions of years. “That’s very accurate when the rocks are 3.4 billion years old,” said Professor Martin Brasier of the University of Oxford, co-leader of the study, published in the journal Nature Geoscience. “At last we have good solid evidence for life over 3.4 billion years ago. It confirms there were bacteria at this time, living without oxygen. Such bacteria are still common today. Sulphur bacteria are found in smelly ditches, soil, hot springs, hydrothermal vents-— anywhere where there’s little free oxygen and they can live off organic matter.” Oxygen appeared in significant quantities in the atmosphere only after the evolution many millions of years later of plant-like microbes which could use sunlight for photosynthesis, producing oxygen as a by-product. Until that point, life on Earth had to make do with sulphur, which can be metabolised in a similar way to obtain energy from food. “I believe we are as close as we have ever been to the very first microbes here... The problem we now have is that there are very few rocks older on Earth in which to search for anything more primitive,” Dr Wacey said. The scientists found the microfossils in the Pilbara, a remote region of Western Australia with a harsh environment of spiky vegetation and red dust. —
The Independent
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Scientists chasing a particle they believe may have played a vital role in creation of the universe indicated they were coming to accept it might not exist after all. But they stressed that if the so-called Higgs boson turns out to have been a mirage, the way would be open for advances into territory dubbed “new physics” to try to answer one of the great mysteries of the cosmos. The CERN research centre, whose giant Large Hadron Collider (LHC) has been the focus of the search, said it had reported to a conference in Mumbai that possible signs of the Higgs noted last month were now seen as less significant. A number of scientists from the centre went on to make comments that raised the possibility that the mystery particle might not exist. “Whatever the final verdict on Higgs, we are now living in very exciting times for all involved in the quest for new physics,” Guido Tonelli, from one of the two LHC detectors chasing the Higgs, said as the new observations were announced. CERN’s statement said new results, which updated findings that caused excitement at another scientific gathering in Grenoble last month, “show that the elusive Higgs particle, if it exists, is running out of places to hide.” The centre’s research director Sergio Bertolucci told the conference, at the Tata Institute of Fundamental Research, that if the Higgs did not exist “its absence will point the way to new physics.” Under what is known as the Standard Model of physics, the boson, which was named after British physicist Peter Higgs, is posited as having been the agent that gave mass and energy to matter just after the Big Bang 13.7 billion years ago. As a result, flying debris from that primeval explosion could come together as stars, planets and galaxies. In the subterranean LHC, which began operating at the end of March 2010, CERN engineers and physicists have created billions of miniature versions of the Big Bang by smashing particles together at just a fraction under the speed of light. The results of those collisions are monitored by hundreds of physicists not just at CERN but in linked laboratories around the world which sift through the vast volumes of information generated by the LHC. Scientists at the US Fermilab near Chicago have been in a parallel search in their Tevatron collider for nearly 30 years. Last month they said they hoped to establish if the Higgs exists by the end of September, when the Tevatron closes down. For some scientists, the Higgs remains the simplest explanation of how matter got mass. It remains unclear what could replace it as an explanation. “We know something is missing, we simply don’t quite know what this new something might be,” wrote CERN blogger Pauline Gagnon. “There are many models out there; we simply need to be nudged in the right direction,” added Gagnon, an experimental physicist. — Reuters
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THIS UNIVERSE When we take up a lighted candle and hold it horizontally in our hands, the flame still points in the upward direction. Why? The air heated by the candle flame and the gases produced in burning of the candle wax are lighter than the surrounding air. Therefore, the process of convection makes them go in the direction opposite to the force of gravity. That direction is upwards. Why does a drop of water have a specific shape? Why does it point in the upward direction? The surface tension of water makes the water spherical, because sphere has the smallest surface area for a given quantity of liquid. But a large drop of water sitting on a surface has a significant weight that flattens the drop a little. This explains the shape of a drop of water on the floor. What will happen when we are in a black hole? What we will see inside it? Long before we get into a black hole we would have ceased to exist. Indeed we would have been broken up into a glue of fundamental particles. Blackholes are not designed for such close intimate inspection by living things.
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Trends SINGAPORE: Scientists have yet to discover, or classify, about 90 per cent of the plant and animal species on the Earth, which is estimated to be home to just under 9 million species, a study says. The study, published in the open-access journal PLoS Biology on Wednesday, vastly increases the estimated richness of life on the planet. More than 1.2 million species have been formally described and named so far. Scientists find weakness in deadly Ebola virus CHICAGO: A protein that helps transport cholesterol inside cells may be a key to developing drugs to treat Ebola, a rare but lethal virus for which there are no known treatments, US researchers said. Laboratory mice bred to produce low levels of this protein-known Niemann-Pick C1 — survived exposure to both Ebola, which causes a hemorrhagic fever, and its cousin, Marburg virus. — Reuters
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The fossilised remains of the oldest known lifeforms on the Earth have been discovered in samples of rock collected near a remote watering hole in the middle of the Australian Outback.
Scientists said the microscopic fossils belonged to primitive bacteria that lived more than 3.4 billion years ago, when the Earth had emerged from a period when it was probably too hostile for life.
