Honey, I doomed the universe

ASTRONOMERS may have unwittingly hastened the end of the Universe by simply looking at it, according to a theory reported in the latest edition of New Scientist.

The novel idea is being aired by two US physicists, who attack the notion that the universe, believed to have been created in the "Big Bang'' some 13.7 billion years ago, will go on, well, forever.

In fact, the poor old cosmos is in a rather delicate state, they say.

Until recently, a common idea was that the energy unleashed in the Big Bang happened when a "false vacuum'' - a bubble of high energy with repulsive gravity - broke down into a safe, zero-energy "ordinary'' vacuum.

But recent evidence has emerged that places a cosmic question-mark over this cosy thought.

For one thing, cosmologists have discovered that the Universe is still expanding.

And, they believe, a strange, yet-to-be-detected form of energy called dark energy pervades the universe, which would explain why the sum of all the visible sources of energy fall way short of what should be out there.

Dark energy, goes the thinking, is a result of the Big Bang and is accelerating the universe's expansion.

If so, the universe is not in a nice, stable zero-vacuum state but simply another "false vacuum'' state that may abruptly decay again - and with cataclysmic consequences.

The energy shift from the decay would destroy everything in the universe, "wiping the slate clean", says Lawrence Krauss of Case Western Reserve University in Cleveland, Ohio.

The good news is: the longer the universe survives, the better the chance that it will mature into a stable state. We are just beyond the crucial switching point, Mr Krauss believed.

The bad news is: the quantum effect, a truly weird aspect of physics that says whenever we observe or measure something, we reset its clock.

Mr Krauss and colleague James Dent pointed to measurements of light from supernovae in 1998 that provided the first evidence of dark energy.

These measurements might have reset the decay clock of the "false vacuum'' back to zero, back before the switching point and to a time when the risk of catastrophic decay was greater than now, said Mr Dent and Mr Krauss.

"Incredible as it seems, our detection of the dark energy may have reduced the life expectancy of the universe,'' said Mr Krauss.

"We may have snatched away the possibility of long-term survival for our universe and made it more likely it will decay.''

The report says the claim is contested by other astrophysicists and adds reassuringly: "The fact that we are still here means this can't have happened yet.''

Quoted from http://www.news.com.au/adelaidenow/story/0,22606,22801758-5005962,00.html:

AdelaideNow... Honey, I doomed the universe

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Radio burst from space mystifies astronomers

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - Astronomers who stumbled upon a powerful burst of radio waves said on Thursday they had never seen anything like it before, and it could offer a new way to search for colliding stars or dying black holes.

They were searching for pulsars -- a type of rotating compacted neutron star that sends out rhythmic pulses of radiation -- when they spotted the giant radio signal.

It was extremely brief but very strong, and appears to have come from about 3 billion light-years away -- a light-year being the distance light travels in a year, or about 6 trillion miles.

"This burst appears to have originated from the distant universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole," said Duncan Lorimer of West Virginia University and the National Radio Astronomy Observatory.

Writing in the journal Science, Lorimer and colleagues said they were looking at old scans done by the Parkes radio telescope in Australia when they spotted the burst.

The burst appears to have lasted 5 milliseconds and may be the radio fingerprint of a single event such as a supernova or the collision of black holes, the astronomers said.

"This burst represents an entirely new astronomical phenomenon," Matthew Bailes of Swinburne University in Australia said in a statement.

Maura McLaughlin of West Virginia University said the event is probably not rare.

"We think there are probably many of these bursts every day that we are just not detecting because we don't have the right kind of surveys of the sky looking for them," McLaughlin said in a telephone interview.

While satellites are detecting x-ray and gamma-ray bursts with regular surveys of large portions of the sky, radiotelescopes generally focus on a very narrow field, she said.

"We are really not sure (what it is)," McLaughlin said.

"We think it has got to be some sort of catastrophic event happening in another galaxy -- like two stars colliding and merging or maybe a black hole. Something kind of exotic," she said.

It is, however, unlikely to be the extraterrestrial equivalent of "I Love Lucy" or other radio or television broadcast.

"It's much too bright. There is no way any civilization that we could possibly think of could create a thing so incredibly powerful," she said.

Quoted from Radio burst from space mystifies astronomers | Tech & Sci | Science | Reuters.com

 

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Parallel universe proof boosts time travel hopes

Science fiction looks closer to becoming science fact, reports Roger Highfield

Parallel universes really do exist, according to a mathematical discovery by Oxford scientists that sweeps away one of the key objections to the mind boggling and controversial idea.

The work has wider implications since the idea of parallel universes sidesteps one of the key problems with time travel. Every since it was given serious lab cred in 1949 by the great logician Kurt Godel, many eminent physicists have argued against time travel because it undermines ideas of cause and effect to create paradoxes: a time traveller could go back to kill his grandfather so that he is never born in the first place.

But the existence of parallel worlds offers a way around these troublesome paradoxes, according to David Deutsch of Oxford University, a highly respected proponent of quantum theory, the deeply mathematical, successful and baffling theory of the atomic world.

He argues that time travel shifts between different branches of reality, basing his claim on parallel universes, the so-called "many-worlds" formulation of quantum theory.

The new work bolsters his claim that quantum theory does not forbid time travel. "It does sidestep it. You go into another universe," he said yesterday, though he admits that there is still a way to go to find schemes to manipulate space and time in a way that makes time hops possible.

"Many sci fi authors suggested time travel paradoxes would be solved by parallel universes but in my work, that conclusion is deduced from quantum theory itself", Dr Deutsch said, referring to his work on many worlds.

The mathematical idea of parallel worlds was first glimpsed by the great quantum pioneer, Erwin Schrodinger, but actually published in 1957 by Hugh Everett III, when wrestling with the problem of what actually happens when an observation is made of something of interest - such as an electron or an atom - with the intention of measuring its position or its speed.

In the traditional brand of quantum mechanics, a mathematical object called a wave function, which contains all possible outcomes of a measurement experiment, "collapses" to give a single real outcome.

Everett came up with a more audacious interpretation: the universe is constantly and infinitely splitting, so that no collapse takes place. Every possible outcome of an experimental measurement occurs, each one in a parallel universe.

If one accepts Everett's interpretation, our universe is embedded in an infinitely larger and more complex structure called the multiverse, which as a good approximation can be regarded as an ever-multiplying mass of parallel universes.

Every time there is an event at the quantum level - a radioactive atom decaying, for example, or a particle of light impinging on your retina - the universe is supposed to "split" into different universes.

A motorist who has a near miss, for instance, might feel relieved at his lucky escape. But in a parallel universe, another version of the same driver will have been killed. Yet another universe will see the motorist recover after treatment in hospital. The number of alternative scenarios is endless.

In this way, the "many worlds" interpretation of quantum mechanics allows a time traveller to alter the past without producing problems such as the notorious grandfather paradox.

But the "many worlds" idea has been attacked, with one theoretician joking that it is "cheap on assumptions but expensive on universes" and others that it is "repugnant to common sense."

Now new research confirms Prof Deutsch's ideas and suggests that Dr Everett, who was a Phd student at Princeton University when he came up with the theory, was on the right track.

Commenting in New Scientist magazine, Prof Andy Albrecht, a physicist at the University of California, Davis, said of the link between probability and many worlds: "This work will go down as one of the most important developments in the history of science."

Quantum mechanics describes the strange things that happen in the subatomic world - such as the way photons and electrons behave both as particles and waves. By one interpretation, nothing at the subatomic scale can really be said to exist until it is observed.

Until then, particles occupy nebulous "superposition" states, in which they can have simultaneous "up" and "down" spins, or appear to be in different places at the same time.

According to quantum mechanics, unobserved particles are described by "wave functions" representing a set of multiple "probable" states. When an observer makes a measurement, the particle then settles down into one of these multiple options.

But the many worlds idea offers an alternative view. Dr Deutsch showed mathematically that the bush-like branching structure created by the universe splitting into parallel versions of itself can explain the probabilistic nature of quantum outcomes. This work was attacked but it has now had rigorous confirmation by David Wallace and Simon Saunders, also at Oxford.

Dr Saunders, who presented the work with Wallace at the Many Worlds at 50 conference at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, told New Scientist: "We've cleared up the obscurities and come up with a pretty clear verdict that Everett works. It's a dramatic turnaround and it means that people now have to discuss Everett seriously."

Dr Deutsch added that the work addresses a three-century-old problem with the idea of probability itself, described by one philosopher, Prof David Papineau, as a scandal. "We didn't really know what probability means," said Dr Deutsch.

There's a convention that it's rational to treat it for most purposes as if we knew it was going to happen even though we actually know it need not. But this does not capture the reality, not least the 0.1 per cent chance something will not happen.

"So," said Dr Deutsch, "the problems of probability, which were until recently considered the principal objection to the otherwise extremely elegant theory of Everett (which removes every element of mysticism and double-talk that have crept into quantum theory over the decades) have now turned into its principal selling point."

 

Quoted from http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2007/09/21/sciuni121.xml:

Parallel universe proof boosts time travel hopes - Telegraph

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Mirror particles form new matter

By Jonathan Fildes Science and technology reporter, BBC News

Fragile particles rarely seen in our Universe have been merged with ordinary electrons to make a new form of matter.

Di-positronium, as the new molecule is known, was predicted to exist in 1946 but has remained elusive to science.

Now, a US team has created thousands of the molecules by merging electrons with their antimatter equivalent: positrons.

The discovery, reported in the journal Nature, is a key step in the creation of ultra-powerful lasers known as gamma-ray annihilation lasers.

"The difference in the power available from a gamma-ray laser compared to a normal laser is the same as the difference between a nuclear explosion and a chemical explosion," said Dr David Cassidy of the University of California, Riverside, and one of the authors of the paper.

"It would have an incredibly high power density."

As a result, there is a huge interest in the technology from the military as well as energy researchers who believe the lasers could be used to kick-start nuclear fusion in a reactor.

Mirror world

Di-positronium was first predicted to exist by theoretical physicist John Wheeler and its component atoms - positronium - were first isolated in 1951.

These short-lived, hydrogen-like atoms consist of an electron and a positron, a positively charged antiparticle.

Antiparticles are the mirror image of ordinary particles.

There is an antiparticle for each type of particle in the Universe. For example, a positively charged proton has a corresponding negatively charged antiproton.

Conventional thinking states that both antimatter and matter should have been created in equal quantities at the birth of the Universe.

The dominance of matter in our world is one of science's most enduring mysteries.

Antimatter only makes fleeting appearances in our Universe when high-energy particle collisions take place, such as when cosmic rays impact the Earth's atmosphere. They are also made in the lab in particle accelerators such as Europe's nuclear research facility, Cern.

These appearances are always short lived because antiparticles are destroyed when they collide with normal matter. The meeting leaves a trace, often as high energy x-rays or gamma-rays.

These emissions are used today in PET (positron emission tomography) scanners to study activity in the brain.

Short lives

The transient nature of antiparticles has made creating and studying di-positronium problematic.

"We've known about this molecule; we're not surprised that it exists but it's taken us more than 50 years to create it in the lab," said Dr Cassidy.

To make the molecule, Dr Cassidy and his team used a specially designed trap to store millions of the positrons.

A burst of 20 million were then focused and blasted at a porous silica "sponge".

"It's like having a trickle of water filling up a bath and then you empty it out and you get a big flush," said Dr Cassidy.

As the positrons rushed into the voids they were able to capture electrons to form atoms. Where atoms met, they formed molecules.

"All we are really doing is implanting lot of positrons into the smallest spot we can, in the shortest time, and hoping that some of them can see each other," said Dr Cassidy.

By measuring the gamma-rays that signalled their annihilation, the team estimated that up to 100,000 of the molecules formed, albeit for just a quarter of a nanosecond (billionth of a second).

Laser beam

Dr Cassidy believes that increasing the density of the positronium in the silicon would create an exotic state of matter known as a Bose-Einstein condensate (BEC).

BECs are usually produced by supercooling atoms so that they merge and begin to behave like one giant atom.

They have been used in many experiments such as the 2003 Harvard study in which scientists were able to trap light.

"At even higher densities, one might expect the material to become a regular, crystalline solid," wrote Professor Clifford Surko, of the University of Californian, San Diego, in an accompanying article.

Taking it one step further, scientists could use the spontaneous annihilation of the BEC, and the subsequent outburst of gamma-rays, to make a powerful laser.

"A gamma-ray laser is the kind of thing that if it existed people would find new uses for it everyday," said Dr Cassidy.

He highlighted an experiment at the National Ignition Facility (NIF) in the US where scientists are using 196 lasers to heat a fuel target to try to kick-start nuclear fusion.

"Imagine doing that but you no longer need hundreds of lasers," he said.

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Earth Might Survive Sun’s Explosion

By DENNIS OVERBYE

What happens to planets when their stars age and die?

That’s not an academic question. About five billion years from now, astronomers say, the Sun will run out of hydrogen fuel and swell temporarily more than 100 times in diameter into a so-called red giant, swallowing Mercury and Venus and dooming life on Earth, but perhaps not Earth itself.

Astronomers are announcing that they have discovered a planet that seems to have survived the puffing up of its home star, suggesting there is some hope that Earth could survive the aging and swelling of the Sun.

The newly discovered planet is a gas giant at least three times as massive as Jupiter. It orbits about 150 million miles from a faint star in the constellation Pegasus known as V 391 Pegasi. But before that star blew up as a red giant sometime in the past and lost half its mass, the planet must have been about as far from its star as the Earth is to the Sun — about 90 million miles — the astronomers led by Roberto Silvotti of the Observatorio Astronomico di Capodimonte in Naples, Italy, calculated.

Dr. Silvotti said that the results showed that a planet at the Earth’s distance “can survive” the red giant and he hoped the discovery would spur searches for more like it. “With some statistics and new detailed models we will be able to say something more even to the destiny of our Earth (which, as we all know, has much more urgent problems by the way),” he said in an e-mail message.

He and his colleagues report their results in Nature on Thursday.

In an accompanying commentary in Nature, Jonathan Fortney of NASA’s Ames Research Center at Moffett Field in Sunnyvale, Calif., wrote, “This system allows us to start examining what will happen to planets around stars such as our own Sun as they too evolve and grow old.”

The star V 391Pegasi is about 4,500 light years away and is now about half as massive as the Sun, burning helium into carbon. It will eventually sigh off another shell of gas and settle into eternal senescence as a “white dwarf.” Meanwhile, the star’s pulsations cause it to brighten and dim every 6 minutes.

After studying the star for seven years, Dr. Silvotti and his colleagues were able to discern subtle modulations in the 6-minute cycle, suggesting that it was being tugged to and fro over a three-year period by a massive planet. “Essentially the observers are using the star as a clock, as if it were a G.P.S. satellite moving around the planet,” explained Fred Rasio, of Northwestern University, who was not involved in the research.

This is not the first time that a pulsing star has been used as such a clock. In 1992, astronomers using the same technique detected a pair of planets (or their corpses) circling the pulsar PSR1257+12.

And , today, X-ray astronomers from the Goddard Space Flight Center in Greenbelt, Md. and the Massachusetts Institute of Technology announced they had detected the remains of a star that had been whittled by radiation down to planetary mass circling a pulsar in the constellation Sagittarius. Those systems have likely endured supernova explosions.

The Pegasus planet has had to survive relatively less lethal conditions, although it must have had a bumpy ride over its estimated 10 billion years of existence. Alan Boss, of the Carnegie Institution of Washington, said “stellar evolution can be a wild ride for a planet that is trying to survive, especially inner planets like Earth.”

When our own Sun begins to graduate from a hydrogen-burning “main sequence” star to a red giant, two effects will compete to determine the Earth’s fate, the astronomers explain. On one hand, as the Sun blows off mass in order to conserve angular momentum, the Earth will retreat to a more distant, safer orbit. But at the same time tidal forces between the Earth and the expanding star will try to drag the planet inward where it could be engulfed. The latter effect, in particular, is difficult to compute.

As a result, said Mario Livio of the Space Telescope Science Institute, of the inner planets, “the Earth’s fate is actually the most uncertain because it is at the border line between being engulfed and surviving.”

A particularly dangerous time for Earth, Dr. Silvotti said, would be at the end of the red giant phase when the Sun’s helium ignites in an explosive flash. In the case of V 391 Pegasi, that explosion sent a large fraction of the star’s mass flying outward.

“This is another reason why the survival of a planet in a relatively close orbit is not trivial,” he said.

 

Quoted from http://www.nytimes.com/2007/09/12/science/space/12cnd-planet.html?ei=5090&en=2e3c30bc2beed102&ex=1347249600&adxnnl=1&partner=rssuserland&emc=rss&pagewanted=print&adxnnlx=1189688477-s+T6k7PXPQeI1iKDt2Y1rg:

Earth Might Survive Sun’s Explosion - New York Times

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Time Travel Machine Outlined

Time Travel Machine Outlined

By Charles Q. Choi, Special to LiveScience

 

A new concept for a time machine could possibly enable distant future generations to travel into the past, research now suggests.

Unlike past ideas for time machines, this new concept does not require exotic, theoretical forms of matter. Still, this new idea requires technology far more advanced than anything existing today, and major questions remain as to whether any time machine would ever prove stable enough to enable actual travel back in time.

Time machine researchers often investigate gravity, which essentially arises when matter bends space and time. Time travel research is based on bending space-time so far that time lines actually turn back on themselves to form a loop, technically known as a "closed time-like curve."

"We know that bending does happen all the time, but we want the bending to be strong enough and to take a special form where the lines of time make closed loops," said theoretical physicist Amos Ori at the Technion-Israel Institute of Technology in Haifa. "We are trying to find out if it is possible to manipulate space-time to develop in such a way."

Many scientists are skeptical as to whether or not time travel is possible. For instance, time machines often are thought to need an exotic form of matter with so-called "negative energy density." Such exotic matter has bizarre properties, including moving in the opposite direction of normal matter when pushed. Such matter could theoretically exist, but if it did, it might be present only in quantities too small for the construction of a time machine.

Ori's latest research suggests time machines are possible without exotic matter, eliminating a barrier to time travel. His work begins with a donut-shaped hole enveloped within a sphere of normal matter.

"We're talking about these closed loops of time, and the simplest kind of closed loops are circles, which is why we have this ring-shaped hole," Ori explained.

Inside this donut-shaped vacuum, space-time could get bent upon itself using focused gravitational fields to form a closed time-like curve. To go back in time, a traveler would race around inside the donut, going further back into the past with each lap.

"The machine is space-time itself," Ori said. "If we were to create an area with a warp like this in space that would enable time lines to close on themselves, it might enable future generations to return to visit our time."

Ori emphasized one significant limitation of this time machine—"it can't be used to travel to a time before the time machine was constructed." His findings are detailed in the Aug. 3 issue of the journal Physical Review D.

A number of obstacles remain, however. The gravitational fields required to make such a closed time-like curve would have to be very strong, "on the order of what you might find close to a black hole," Ori told LiveScience. "We don't have any way of creating such strong gravitational fields today, and we certainly have no way of manipulating any such gravitational fields."

Even if time machines were technically feasible, the gravitational fields involved need to be manipulated in very specific, accurate ways, and Ori said his calculations suggest any time machine could be very unstable, meaning "the tiniest deviations might keep one from working. We need to explore the problem of stability of time machines further."

Theoretical physicist Ken Olum of Tufts University in Medford, Mass., who did not participate in this study, was skeptical concerning how this new model claimed to sidestep prior theoretical objections to time travel.

Still, Olum noted, "It's important if it's right—that there really is some kind of loophole. So this should be scrutinized very closely." The point of such work, he added, was to "expand the bounds of what's possible, what kind of things we can have and what kinds of things we cannot have."

 

Quoted from http://www.livescience.com/strangenews/070820_time_machine.html:

Time Travel Machine Outlined | LiveScience

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Scientists break the speed of light

By ANDREW LEVY

It was supposed to be the one speed limit you cannot break.

But scientists claim to have demonstrated there is the possibility of travel faster than the speed of light.

The feat contradicts one of the key tenets of Einstein's special theory of relativity - that nothing, under any circumstances, can move faster than 186,000 miles per second, or the speed of light.

Speed of light beaten: One of the key tenets of Einstein's theory of relativity is proved wrong

Traveling faster than light also, in theory, turns back time. According to conventional physics, an astronaut moving beyond light speed would arrive at his destination before leaving.

But two German physicists claim to have forced light to overcome its own speed limit using the strange phenomenon of quantum tunneling, in which particles summon up the energy to cross an apparently uncrossable barrier.

Their experiments focused on the travel of microwave photons - energetic packets of light - through two prisms.

When the prisms were moved apart, most photons reflected off the first prism they encountered and were picked up by a detector.

But a few appeared to "tunnel" through a gap separating them as if the prisms were still held together.

Although these photons had traveled a longer distance, they arrived at their detector at the same time as the reflected photons. This suggests that the transit between the two prisms was faster than the speed of light.

Dr Gunter Nimtz, of the University of Koblenz, told the magazine New Scientist: "For the time being, this is the only violation of special relativity that I know of."

Quoted from http://www.dailymail.co.uk/pages/live/articles/technology/technology.html?in_article_id=475587&in_page_id=1965

Scientists break the speed of light | the Daily Mail

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Saturn's sixtieth moon discovered

A new moon has been discovered orbiting Saturn - bringing the planet's latest moon tally up to 60.

The body was spotted in a series of images taken by cameras onboard the Cassini spacecraft.

Initial calculations suggest the moon is about 2km-wide (1.2 miles) and its orbit sits between those of two other Saturnian moons, Methone and Pallene.

The Cassini Imaging Team, who found the object, said Saturn's moon count could rise further still.

New family

The moon appears as a dim speck in images taken by the Cassini probe's wide-angle camera on 30 May 2007.

Professor Carl Murray, a Cassini Imaging Team scientist from Queen Mary, University of London (QMUL), said: "After initially detecting this extremely faint object, we carried out an exhaustive search of all Cassini images to date and were able to find further detections."

It is thought, like many of Saturn's other moons, to be mostly made up of ice and rock.

The body's proximity to Methone and Pallene suggests the three satellites may constitute a family of moons.

"Naturally we are going to use Cassini's cameras to search for additional family members," added Professor Murray.

The moon, currently dubbed Frank by the scientists who discovered it, has yet to be officially named. This decision will be taken by the International Astronomical Union.

Professor Murray said: "The Saturnian system continues to amaze and intrigue us with many hidden treasures being discovered the more closely we look."

'Epic journey'

The Cassini-Huygens mission, a collaboration between the US space agency (Nasa), the European Space Agency (Esa) and the Italian Space Agency (ASI), set off on its mission to explore Saturnian system in 1997.

The Cassini space probe arrived at its destination in 2004, while the Huygens probe, initially carried onboard Cassini, landed on Saturn's largest moon, Titan, in 2005.

Professor Keith Mason, chief executive of the UK's Science and Technology Facilities Council (STFC), said: "It is amazing to think that when Cassini embarked upon its epic journey to Saturn in 1997, we only knew about 18 of its moons.

"Since then, through observations from ground based telescopes and the Cassini spacecraft, a further 42 have been identified."

 

This was found at BBC News.

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Tests of "Big Bang" project put off to 2008

By Robert Evans

GENEVA (Reuters) - First tests in a scientific project aimed at solving mysteries of the universe and the "Big Bang" which created it have been put off from November to late April or early May next year, an official said on Wednesday.

James Gillies, spokesman for the CERN particle research centre near Geneva, said the delay was due to a series of minor problems with some elements in the vast array of equipment.

"We now intend to make the tests, which will allow the technicians to drive the machine, in late April or early May and then to go into full start up as planned by next summer," Gillies said.

The project at CERN, the European Organization for Nuclear Research which straddles the Swiss and French border, involves smashing particles together at high speed in a channel around an oval-shaped 27-km (17 mile) underground tunnel.

Researchers on the project, the Large Hadron Collider (LHC), say this will recreate in miniature the conditions which existed nanoseconds after the Big Bang some 15 billion years ago and should allow them to see what happened next.

CERN says the experiment will also probe for knowledge about "dark matter" -- the invisible mass of energy that is believed to make up 96 percent of the universe.

The LHC project, involving scientists from CERN's 26 member countries and many other nations in gathering and processing the data from many billions of particle collisions every day, has been in construction for 15 years.

It is expected to be in operation for another 15.

At the centre of the experiment, which cost many billions of dollars to set up, are vast magnets in cathedral-size caverns around the tunnel some 100 meters (300 feet) underground.

Originally two weeks of relative low-speed testing of the circuit had been planned for November, just before CERN closes down its particle accelerators for four months to save costly energy during the winter.

But smaller magnets burst during pressure tests at the end of March, and unscheduled work resulting from that incident has meant there would not be sufficient time for the preliminary "driving" tests before the shutdown, Gillies said.

This was found at Reuters.

Nifty Video About Time Travel

Planet-hunters find bonanza of new solar systems

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - Planet-seekers who have spotted 28 new planets orbiting other stars in the past year say Earth's solar system is far from unique and there could be billions of habitable planets.

The most recent planet discoveries bring the number of known exoplanets -- planets outside our solar system -- to 236, the researchers told a meeting of the American Astronomical Society in Honolulu on Monday.

"We are beginning to see that our home is not a rarity in the universe," said Geoffrey Marcy, a professor of astronomy at the University of California Berkeley, who led the team.

"We are easily able to detect giant planets like Jupiter and Saturn around other stars. Most orbit far from the star like our own Jupiter and Saturn orbit from the sun," Marcy said in a telephone interview.

"It's a common structure among planetary systems."

New techniques allow astronomers to detect planets that are not enormous although Earth-sized objects cannot yet be seen, said the researchers, who have posted details of their findings on the Internet at http://exoplanets.org.

Four of the systems also have multiple planets, like Earth's own with its sun, eight planets (Pluto was demoted from planet status) and smaller orbiting objects.

"We are finding that most stars have not just one planet but when we find one there is a second or a third or a fourth," Marcy said.

"The ... attribute which really has us the most excited is this new planet which we found three years ago," Marcy said. The Neptune-like planet orbiting the star Gliese 436 has intrigued scientists because it appears to be covered with water -- albeit rock-hard, hot water in a most un-Earthlike chemical state because of the intense pressures on the planet.

"JUMPING OUT OF OUR CLOTHES"

Earlier this month, Swiss and Belgian researchers imaged the star as this planet crossed between it and the Earth. The tiny change in the star's light gave them the planet's diameter and density.

"From the density of two grams per cubic centimeter -- twice that of water -- it must be 50 percent rock and about 50 percent water, with perhaps small amounts of hydrogen and helium," Marcy said.

"Now we are very sure it has a rocky core and this giant thick envelope of water," he added.

"This is why we are jumping out of our clothes. It is the first time we have determined the structure of one of these extrasolar planets. It is rocky like Earth but it has a lot of water which is the essential ingredient for life."

This is almost certainly happening over and over again, Marcy said. Scientists had theorized this for decades but now the hard evidence is starting to pour in.

"Our Milky Way galaxy has 200 billion stars. I would estimate that 10 percent of them, perhaps, have planets that are habitable," Marcy said.

"There are hundreds of billions of galaxies, all of which are more or less like our Milky Way Galaxy, which is tens of billions of planets like our own."

There is one unusual property to our solar system: the nearly circular orbits of the planets, which gives a consistent dose of radiation from the Sun.

Other solar systems seen so far are not usually like this. "Most of the planets are not in circular orbits around the host star but in elongated ones called elliptical orbits," Marcy said.

"We enjoy nearly constant temperatures throughout the year," he added. "If the Earth got too close to the Sun, the Earth would heat up, the water would boil off and that would be bad." Too far, and it would freeze.

"An elongated orbit could not sustain life," Marcy said.

This was found at Reuters.

Astronomers Find Planet Outside Solar System

The most enticing property yet found outside our solar system is about 20 light years away in the constellation Libra, a team of European astronomers said today.

The astronomers have discovered a planet five times as massive as the Earth orbiting a dim red star known as Gliese 581.

It is the smallest of the 200 or so planets that are now known to exist outside of our solar system, called extrasolar or exoplanets. Moreover, it orbits its home star within the so-called habitable zone where surface water, the staff of life, could exist if other conditions are right, said Stephane Udry of the Geneva Observatory.

“We are at the right place for that,” said Dr. Udry, the lead author of a paper describing the discovery that has been submitted to the journal Astronomy & Astrophysics.

But he and other astronomers cautioned that it was far too soon to conclude that liquid water was there without more observations. Sara Seager, a planet expert at the Massachusetts Institute of Technology said, “For example, if the planet had an atmosphere more massive than Venus’s, then the surface would likely be too hot for liquid water.”

Nevertheless, the discovery in the Gliese 581 system, where a Neptune-size planet was discovered two years ago and another planet of eight Earth masses is now suspected, catapults that system to the top of the list for future generations of space missions.

“On the treasure map of the Universe, one would be tempted to mark this planet with an X,” said Xavier Delfosse, a team member from Grenoble University in France, according to a news release from the European Southern Observatory, a multinational collaboration based in Garching, Germany.

“It’s 20 light years. We can go there,” said Dimitar Sasselov, of the Harvard-Smithsonian Center for Astrophysics, who studies the structure and formation of planets.

The new planet was discovered by the wobble it causes in its home star’s motion as it orbits, the method by which most of the known exo-planets have been discovered. Dr. Udry’s team used an advanced spectrograph on a 141-inch diameter telescope at the European observatory in La Silla, Chile.

The smallest previous exo-planet was roughly six Earth masses, discovered by a team led by the American planet hunters Geoff Marcy of the University of California, Berkeley, and Paul Butler of the Carnegie Institution of Washington. The two astronomers are longtime rivals of the Swiss group founded by Michel Mayor, of the Geneva Observatory. Of the new result, Dr. Marcy said, “The Swiss do excellent work, so I’m sure that they have a strong case for it.”

The planet, officially known as Gliese 581c, circles the star every 13 days at a distance of about 7 million miles. According to models of planet formation developed by Dr. Sasselov and his colleagues, such a planet should be about half again as large as the Earth and be composed of rock and water, what the astronomers now call a “super Earth.”

The most exciting part of the new find, Dr. Sasselov said, is that it “basically tells you these kinds of planets are very common.” Because they could stay geologically active for billions and billion of years, Dr. Sasselov said he suspects that such planets could be even more congenial for life than the Earth. NASA’s coming Kepler mission, he added, would probably find hundreds of these super Earths.

Although the new planet is much closer to its star than the Earth is to the Sun, its star, a so-called red dwarf, is only about a hundredth as luminous as the Sun. So 7 million miles is a comfortable cuddling distance.

How hot the planet would get, Dr. Udry said, would depend on how much light the planet reflects, or its albedo. Using the Earth and Venus as two extreme examples, he estimated that temperatures on the surface of the planet should range from 0 to 40 degrees centigrade. “It’s just right in the good range,” he said. “Of course, we don’t know anything about its albedo.”

One problem is that the wobble technique only gives masses of planets. To measure their actual size and thus their densities, astronomers have to catch them in the act of passing in front of or behind their stars. Such transits can also reveal if the planets have atmospheres and what they are made of. Earlier this month, such observations with the Spitzer Space Telescope returned the first tentative indications of water in the atmosphere of another exoplanet in the constellation Pegasus.

Dr. Udry said he and Dr. Sasselov would be observing the Gliese system with a Canadian space telescope named Most, to see if there are any dips in starlight caused by the new planet. Failing that, they said, the best chance for more information about the Gliese system lies with NASA’s Terrestrial Planet Finder and the European Space Agency’s Darwin missions, which are designed to study Earth-like planets, but have been delayed by political, technical and financial difficulties.

“We are starting to count the first targets,” Dr. Udry said.

This was found at New York Times

Discovery of new family of pseudo-metallic chemicals

The periodic table of elements, all 111 of them, just got a little competition. A new discovery by a University of Missouri-Columbia research team, published in Angewandte Chemie allows scientists to manipulate a molecule discovered 50 years ago in such as way as to give the molecule metal-like properties, creating a new, "pseudo" element. The pseudo-metal properties can be adjusted for a wide range of uses and might change the way scientists think about attacking disease or even building electronics.

Five decades ago, Fred Hawthorne, professor of radiology and director of the International Institute for Nano and Molecular Medicine at MU, discovered an extremely stable molecule consisting of 12 boron atoms and 12 hydrogen atoms. Known as "boron cages," these molecules were difficult to change or manipulate, and sat dormant in Hawthorne's laboratory for many years.

Recently, Hawthorne's scientific team found a way to modify these cages, resulting in a large, new family of nano-sized compounds. In their study, which was published this month, Hawthorne, and Mark Lee, assistant professor at the institute and first author of the study, found that attaching different compounds to the cages gave them the properties of many different metals.

"Since the range of properties for these pseudo-metals is quite large, they might be referred to as 'psuedo-elements belonging to a completely new pseudo-periodic table,'" Lee said.
Potential applications of this discovery are abundant, especially in medicine.

"All living organisms are essentially a grand concert of chemical reactions involving the transfer of electrons between molecules and metals,'" Lee said. "The electron transfer properties of this new family of molecules span the entire range of those found within living systems. Because of this, these pseudo-metals may be tuned for use as specific probes in living systems to detect or treat disease at the earliest state."

In addition, because the compounds possess such a wide range of flexibility, they might have ramifications for nanotechnology and various kinds of electronics.

"This single discovery could open entirely new fields of study because of the controlled variability of the compounds," Lee said. "We have the ability to change the properties of these pseudo-metals, which gives us the opportunity to tailor them to our needs, whether that is biomedical, chemical or electronic applications, some of which may utilize nanoscience."

Source: University of Missouri-Columbia

On this day 1955

1955: Albert Einstein dies
Albert Einstein has died in hospital in Princeton, New Jersey, aged 76.
The eminent scientist and originator of the theory of relativity was admitted to hospital three days ago with an internal complaint.

In recent years Dr Einstein had lived a secluded life although he was still a member of staff at the Institute for Advanced Study at Princeton University.

In a statement issued following the scientist's death, US President Dwight Eisenhower said: "No other man contributed so much to the vast expansion of the 20th century knowledge.

"Yet no other man was more modest in the possession of the power that is knowledge, more sure that power without wisdom is deadly.

"To all who live in the nuclear age, Albert Einstein exemplified the mighty creative ability of the individual in a free society."

'Disruptive' behaviour

Albert Einstein was born on 14 March 1879 to Jewish parents at Ulm, Wurttenburg in Germany.

Soon afterwards the family moved to Munich where the young Einstein began his education at the Luitpold Gymnasium.

His early academic career was notable only for the fact he was asked to leave his school for "disruptive" behaviour.

But he had always excelled at mathematics - a subject which would later make him the most renowned scientist in the world.

In 1896 Einstein entered the Swiss Federal Polytechnic School in Zurich to train as a physics and maths teacher.

But he struggled to get a job, largely due to the fact he was German, so, in 1902, he accepted a job as a technical assistant in the Swiss Patent Office.

It was during his seven years at the Patent Office that, in his spare time, he worked on his mathematical theories which would eventually take the world by storm.

The Special Theory of Relativity, which describes the motion of particles moving close to the speed of light, was published in 1905.

In the years that followed, Einstein took up senior academic posts in Berne and Zurich. In 1911 he became Professor of Theoretical Physics in Prague but returned to Zurich a year later.

However, well-known German physicists, Walter Nernst and Professor Planck, were eager for Einstein to return to Berlin.

In 1913 they persuaded him to take up the position of director of the projected research institute for physics in the University of Berlin and become a member of the Royal Prussian Academy of Science.

Einstein's General Theory of Relativity was published in 1916. In 1921 he was awarded the Nobel Prize for physics.

He kept the positions in Berlin until 1933, when he accepted a part-time post at Princeton University in America.

His plan was to divide his time between Germany and America but in the same year the Nazis came to power and Einstein, being a Jew, never returned to his birthland.

This was found at BBC.

Light can bend liquid

Agençe France-Presse

The gentle radiation pressure of light was able to deform and direct a stream of a special soapy liquid.

Just the gentle pressure of a beam of light is enough to bend and direct streams of a special liquid, according to a study to be published this week.

The discovery could lead to new advances in biomedicine and biotechnology by offering a way to control the flow of fluids through extremely narrow channels.

Physicists from France and the U.S. have used a laser beam to produce a surprisingly long and steady jet of soapy liquid that is narrower than a human hair. The researchers were then able to push the liquid into a "hump-like shape", by directing the laser at a different angle.

The discovery was made by accident while University of Chicago fluid scientist, Wendy Zhang, was visiting colleagues at the University of Bordeaux in France.

Here, physicist Jean-Pierre Delville had observed a strange and unexpected result after completing a previous experiment studying the behaviour of fluid under a low intensity laser beam.

Delville then turned up the laser power just to see what it could do, much the same way a motorist might test the performance of a powerful car on a deserted road, said Zhang. "He turned up the power and then saw this amazing thing," she said. "Because he has a lot of experience with optics, he realized that what he saw was strange."

What they found was that the laser beam was able to direct and bend the fine jet of liquid.

The find, Which was further probed by lead author and Chicago graduate student Robert Schroll, is detailed in the 30 March edition of the journal Physical Review Letters.

While heat can set liquid in motion, the researchers discovered that in this case it was the gentle radiation pressure generated by photons - discrete packets of light energy - that moved the fluid.

This radiation pressure is so slight it ordinarily goes unnoticed, but the liquid used in the Bordeaux experiment has such an "incredibly weak surface" that even light can deform it. "It's basically soap," Zhang said of the experimental liquid, which was a mixture of water and oil that had been precisely blended to display varying characteristics under certain conditions.

Further research is now needed to determine whether this light-driven flow could advance 'microfluidics' – that is the science of controlling fluid flow through channels thinner than a human hair. Conventional microfluidics techniques use channels etched into computer chips to control fluid flow. While this is a relatively easy process, Zhang said, a laser-driven microfluidics system might allow researchers to make more rapid adjustments.

"Here I've created a channel, but I didn't have to make anything. I just shined a light," Zhang said.

Big magnet ready to face the big questions of the universe

World's largest superconducting magnet switches on

The largest superconducting magnet ever built has successfully been powered up to its operating conditions at the first attempt. Called the Barrel Toroid because of its shape, this magnet is a vital part of ATLAS, one of the major particle detectors being prepared to take data at CERN's Large Hadron Collider (LHC), the new particle accelerator scheduled to turn on in November 2007. ATLAS will help scientists probe the big questions of the Universe – what happened in the moments after the Big Bang? Why does the material in the Universe behave the way it does? Why is the Universe we can see made of matter rather than anti-matter?
UK scientists are a key part of the ATLAS collaboration and Dr Richard Nickerson, UK ATLAS project leader, who is from the University of Oxford welcomed this important milestone "The toroidal magnets are critical to enabling us to measure the muons (a type of particle) produced in interactions. These are vital to a lot of the physics we want to study, so the successful test of the magnets is a great step forward."

The ATLAS Barrel Toroid consists of eight superconducting coils, each in the shape of a round-cornered rectangle, 5m wide, 25m long and weighing 100 tonnes, all aligned to millimetre precision. It will work together with other magnets in ATLAS to bend the paths of charged particles produced in collisions at the LHC, enabling important properties to be measured. Unlike most particle detectors, the ATLAS detector does not need large quantities of metal to contain the field because the field is contained within a doughnut shape defined by the coils. This allows the ATLAS detector to be very large, which in turn increases the precision of the measurements it can make.

At 46m long, 25m wide and 25m high, ATLAS is the largest volume detector ever constructed for particle physics. Among the questions ATLAS will focus on are why particles have mass, what the unknown 96% of the Universe is made of, and why Nature prefers matter to antimatter. Some 1800 scientists from 165 universities and laboratories (including 12 from the UK) representing 35 countries are building the ATLAS detector and preparing to take data next year.

The ATLAS Barrel Toroid was first cooled down over a six-week period in July-August to reach –269oC. It was then powered up step-by-step to higher and higher currents, reaching 21 thousand amps for the first time during the night of 9 November. This is 500 amps above the current needed to produce the nominal magnetic field. Afterwards, the current was switched off and the stored magnetic energy of 1.1 GJ, the equivalent of about 10 000 cars travelling at 70km/h, has now been safely dissipated, raising the cold mass of the magnet to –218oC.

"We can now say that the ATLAS Barrel Toroid is ready for physics," said Herman ten Kate, ATLAS magnet system project leader.

The ATLAS Barrel Toroid is financed by the ATLAS Collaboration and has been built through close collaboration between the French CEA-DAPNIA laboratory (originator of the magnet's design), Italy's INFN-LASA laboratory and CERN. Components have been contributed in-kind by national funding agencies from industries in France (CEA), Italy, Germany (BMBF), Spain, Sweden, Switzerland, Russia, and the Joint Institute for Nuclear Research (JINR), an international organization based near Moscow. The final integration and test of the coils at CERN, as well as assembly of the toroid in the ATLAS underground cavern, was done with JINR providing most of the manpower and heavy tooling.

###

Notes for Editors

Images

Pictures of the Barrel Toroid Magnet can be downloaded from http://atlasexperiment.org/atlas_photos/toroid/toroid_barrel.html

The 8 elements of the magnet are clearly visible in the picture of the ATLAS detector.

Contacts

Dr Richard Nickerson

University of Oxford

Tel +44 1865 273318

r.nickerson1@physics.ox.ac.uk

James Gillies

CERN press office

Tel. +41 22 767 41 01

James.Gillies@cern.ch

InterAction Collaboration media contacts:

• Fermilab, USA: Kurt Riesselmann, 630-840-3351, kurtr@fnal.gov
  
• INFN, Italy: Barbara Gallavotti, + 39 06 6868162 (office), + 39 335 6606075 (cell phone), + 39 06 6868162 (fax), Barbara.Gallavotti@presid.infn.it
  
• KEK, High Energy Accelerator Research Organization, Japan: Youhei Morita, + 81 029 8796047, + 81 029 8796049 (fax), youhei.morita@kek.jp
  
• IN2P3-CNRS, France: Alain de Bellefon, + 33 01 44 96 47 51, bellefon@in2p3.fr
  
• Joint Institute for Nuclear Research, Dubna, Russia: Boris Starchenko, + 7 096 221 6 38 24, irinak@jinr.ru
  
• Particle Physics and Astronomy Research Council (PPARC), United Kingdom: Peter Barratt, + 44 (0) 1793 442025, + 44 (0) 787 602 899 (mobile), peter.barratt@pparc.ac.uk
  
  
  
• Lawrence Berkeley National Laboratory, California, USA: Ron Kolb, + 1 510 486 7586, rrkolb@lbl.gov
  
  

The Particle Physics and Astronomy Research Council (PPARC) is the UK's strategic science investment agency. It funds research, education and public understanding in four areas of science - particle physics, astronomy, cosmology and space science.

PPARC is government funded and provides research grants and studentships to scientists in British universities, gives researchers access to world-class facilities and funds the UK membership of international bodies such as the European Laboratory for Particle Physics (CERN), the European Southern Observatory (ESO) and the European Space Agency. It also contributes money for the UK telescopes overseas on La Palma, Hawaii, Australia and in Chile, the UK Astronomy Technology Centre at the Royal Observatory, Edinburgh and the MERLIN/VLBI National Facility, which includes the Lovell Telescope at Jodrell Bank observatory.