Tuesday, February 28, 2006
Hey, Look at That Star !!!
A star in a galaxy not so far way, at least in cosmic terms, is exploding, astronomers say. Already the star outshines its entire galaxy, a smudge of light about 440 million light-years away in the constellation Aries. But that, astronomers believe, is still only the beginning, and telescopes around the world are being turned toward Aries in anticipation of documenting one of the rarest and most violent events in nature, a supernova explosion.
The conflagration was detected on Saturday as a long burst of gamma rays by NASA's Swift satellite. Such bursts have been linked to supernova explosions in which a massive star collapses into a black hole.
This burst, however, is an oddball. It lasted nearly 2,000 seconds, or about half an hour, 100 times longer than a typical burst, and was much weaker, said John Nousek, a Pennsylvania State astronomer and the director of the Swift mission.
"It's so early we don't have a clear answer to what it is," Dr. Nousek said yesterday. "What is clear is that it is nearby and associated with supernova."
Nobody will need sunglasses. At maximum light, Dr. Nousek said, the exploding star would probably be about twice as bright as it is now, within reach of professional and large amateur telescopes, but not the unaided eye. Usually the bursts are so far away across the cosmos that the visual light from the actual explosions is never seen, but this one, called GRB 060218, after the date on which it was discovered, is the second closest ever found, practically next door, leaving astronomers with their armada of instruments in an enviable position.
Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics, who called the event "a lot of fun," said, "We have a lot to learn about these super-duper explosions, and it is great to have an agile satellite like Swift working so beautifully."
Thursday, February 09, 2006
Go Sweden Go !!!
The attempt is being planned by a committee of industrialists, academics, car manufacturers, farmers and others. The country aims to replace all fossil fuels with renewables before climate change damages economies and growing oil scarcity leads to price rises.
According to the Guardian newspaper, a Swedish minister said oil dependency could be broken by 2020.
The Royal Swedish Academy of Sciences is worried that oil supplies are peaking, shortly to dwindle, and that high oil prices could cause global economic recession. "Our dependency on oil should be broken by 2020," said Mona Sahlin, Sweden's minister of sustainable development. "There shall always be better alternatives to oil, which means no house should need oil for heating, and no driver should need to turn solely to gasoline."
The Scandinavian country, which was hard hit by oil price rises in the 1970s, now gets the majority of its electricity from nuclear and hydroelectric power. In 2003, 26% of all energy consumed came from renewables, compared with an EU average of 6%.
The oil committee is to report to parliament in several months. Swedish energy ministry officials said they expected the panel to recommend further development of biofuels derived from its substantial forests. It was also expected to expand other renewable energies such as wind and wave power.
Monday, February 06, 2006
... and there was light (matter)
| By Jonathan Amos BBC News science reporter |
This strange material that dominates the Universe but which is invisible to current telescope technology is one of the great enigmas of modern science.
That it exists is one of the few things on which researchers have been certain. But now an Institute of Astronomy, Cambridge, team has at last been able to place limits on how it is packed in space and measure its "temperature".
"It's the first clue of what this stuff might be," said Professor Gerry Gilmore. "For the first time ever, we're actually dealing with its physics," he told the BBC News website........
........'Magic volume'
Astronomers cannot detect dark matter directly because it emits no light or radiation. Its presence, though, can be inferred from the way galaxies rotate: their stars move so fast they would fly apart if they were not being held together by the gravitational attraction of some unseen material.
Such observations have established that dark matter makes up more than 95% of all cosmic material. Now, the Cambridge team has provided new information with its detailed study of 12 dwarf galaxies that skirt the edge of our own Milky Way.
Using the biggest telescopes in the world, including the Very Large Telescope facility in Chile, the group has made detailed 3D maps of the galaxies, using the movement of their stars to "trace" the impression of the dark matter among them and weigh it very precisely.
With the aid of 7,000 separate measurements, the researchers have been able to establish that the galaxies contain about 400 times the amount of dark matter as they do normal matter....
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| | If this 'temperature' for the dark matter is correct, then it has huge implications for direct searches for these mysterious particles Prof Bob Nichol Institute of Cosmology and Gravitation, Portsmouth |
"It looks like you cannot ever pack it smaller than about 300 parsecs - 1,000 light-years; this stuff will not let you. That tells you a speed actually - about 9km/s - at which the dark matter particles are moving because they are moving too fast to be compressed into a smaller scale."...
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... how many to change the light bulb?
| | | VIEWPOINT Matt Prescott |
Governments are wrestling with problems of rising energy demands, rising costs and the spectre of climate change. In this week's Green Room, Dr Matt Prescott argues there is an easy first step to dealing with all three issues - banning the traditional light bulb.
| | They waste so much energy that if they were invented today, it is highly unlikely they would be allowed onto the market Matt Prescott |
Listening to most politicians, you would think the world's energy problems can be solved only by building ever bigger power stations and burning ever more fuel.
Not so; and it certainly cannot solve the coming climate crisis. After turning off unnecessary pieces of equipment, improved energy efficiency is the cheapest way for developing countries to maximise their use of limited energy supplies, and for developed countries to achieve cuts in their carbon dioxide emissions.
One quick and simple option for improving energy efficiency would be to make greater use of compact fluorescent light bulbs.
Each one of these bulbs produces the same amount of light as an incandescent light bulb whilst being responsible for the emission of 70% less carbon dioxide. It also saves money; about £7 ($12) per year in the UK, more or less in other countries depending on electricity prices...
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... and there was New Orleans
| By Helen Lambourne Researcher, BBC Horizon |
The BBC's Horizon programme has spoken to the scientists who are now confronting the real possibility that New Orleans may be the first of many cities worldwide to face extinction.
Modern day New Orleans was a city that defied the odds. Built on a mosquito-infested swamp squashed between two vast bodies of water in what is essentially a bowl, its very existence seemed proof of the triumph of engineering over nature.
But on the 29 August 2005 New Orleans took a hit from Hurricane Katrina and overnight was turned into a Venice from hell.
| | If you want New Orleans back you have to do some very fundamental things Shea Penland, University of New Orleans |
Coastal Geologist Shea Penland from the University of New Orleans knows every inlet, every cove and every stretch of marsh that surrounds New Orleans.
He also knew that what had been thought of as wasteland for years were critical to the survival of the city.
"The first line of defence isn't the levee in your backyard, the first line of defence is that marsh in your backyard and we're learning what that means."...
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