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Tuesday, November 6, 2007

Scientists Predict How To Detect A Fourth Dimension Of Space

Scientists Predict How To Detect A Fourth Dimension Of Space

Einstein's Theory of Relativity is going to have to defend itself against a new five-dimensional theory of gravity.

Scientists at Duke and Rutgers universities have developed a mathematical framework they say will enable astronomers to test a new five-dimensional theory of gravity that competes with Einstein's General Theory of Relativity.
Charles R. Keeton of Rutgers and Arlie O. Petters of Duke base their work on a recent theory called the type II Randall-Sundrum braneworld gravity model. The theory holds that the visible universe is a membrane (hence "braneworld") embedded within a larger universe, much like a strand of filmy seaweed floating in the ocean.

The "braneworld universe" has five dimensions -- four spatial dimensions plus time -- compared with the four dimensions -- three spatial, plus time -- laid out in the General Theory of Relativity.

The framework Keeton and Petters developed predicts certain cosmological effects that, if observed, should help scientists validate the braneworld theory. The observations, they said, should be possible with satellites scheduled to launch in the next few years.

If the braneworld theory proves to be true, "this would upset the applecart," Petters said. "It would confirm that there is a fourth dimension to space, which would create a philosophical shift in our understanding of the natural world."

The scientists' findings appeared May 24, 2006, in the online edition of the journal Physical Review D. Keeton is an astronomy and physics professor at Rutgers, and Petters is a mathematics and physics professor at Duke. Their research is funded by the National Science Foundation.

The Randall-Sundrum braneworld model -- named for its originators, physicists Lisa Randall of Harvard University and Raman Sundrum of Johns Hopkins University -- provides a mathematical description of how gravity shapes the universe that differs from the description offered by the General Theory of Relativity.

Keeton and Petters focused on one particular gravitational consequence of the braneworld theory that distinguishes it from Einstein's theory.

The braneworld theory predicts that relatively small "black holes" created in the early universe have survived to the present. The black holes, with mass similar to a tiny asteroid, would be part of the "dark matter" in the universe. As the name suggests, dark matter does not emit or reflect light, but does exert a gravitational force.

The General Theory of Relativity, on the other hand, predicts that such primordial black holes no longer exist, as they would have evaporated by now.

"When we estimated how far braneworld black holes might be from Earth, we were surprised to find that the nearest ones would lie well inside Pluto's orbit," Keeton said.

Petters added, "If braneworld black holes form even 1 percent of the dark matter in our part of the galaxy -- a cautious assumption -- there should be several thousand braneworld black holes in our solar system."

But do braneworld black holes really exist -- and therefore stand as evidence for the 5-D braneworld theory?

The scientists showed that it should be possible to answer this question by observing the effects that braneworld black holes would exert on electromagnetic radiation traveling to Earth from other galaxies. Any such radiation passing near a black hole will be acted upon by the object's tremendous gravitational forces -- an effect called "gravitational lensing."

"A good place to look for gravitational lensing by braneworld black holes is in bursts of gamma rays coming to Earth," Keeton said. These gamma-ray bursts are thought to be produced by enormous explosions throughout the universe. Such bursts from outer space were discovered inadvertently by the U.S. Air Force in the 1960s.

Keeton and Petters calculated that braneworld black holes would impede the gamma rays in the same way a rock in a pond obstructs passing ripples. The rock produces an "interference pattern" in its wake in which some ripple peaks are higher, some troughs are deeper, and some peaks and troughs cancel each other out. The interference pattern bears the signature of the characteristics of both the rock and the water.

Similarly, a braneworld black hole would produce an interference pattern in a passing burst of gamma rays as they travel to Earth, said Keeton and Petters. The scientists predicted the resulting bright and dark "fringes" in the interference pattern, which they said provides a means of inferring characteristics of braneworld black holes and, in turn, of space and time.

"We discovered that the signature of a fourth dimension of space appears in the interference patterns," Petters said. "This extra spatial dimension creates a contraction between the fringes compared to what you'd get in General Relativity."

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Embry-Riddle And Zero Gravity To Collaborate On Weightless Flights

Embry-Riddle And Zero Gravity To Collaborate On Weightless Flights

Researchers, teachers and students will have access to weightless and variable-gravity conditions under a new agreement between Embry-Riddle Aeronautical University and Zero Gravity Corp. (Zero-G). Embry-Riddle and Zero-G will work together to integrate weightless flights and space science workshops for K-12 teachers, develop experiment programs for high school and college students, and expand microgravity, lunar gravity, and Mars gravity research opportunities aboard Zero-G's G-Force One aircraft.
The collaboration will include Embry-Riddle's support for development of the Stephen Hawking Microgravity Education and Research Center. The Hawking Center is an initiative of Space Florida, Florida's aerospace development agency, conceived after the renowned astrophysicist flew aboard G-Force One earlier this year. Embry-Riddle's student researchers are frequent flyers on NASA's microgravity educational flights, making the university well qualified to work with Zero-G and Space Florida to develop Hawking Center research projects.

"Zero-G has already demonstrated an outstanding commitment to providing professional development for science and mathematics teachers, and has a unique platform for supporting innovative R and D," said Michael Hickey, director of Embry-Riddle's TeachSpace educational program. "We look forward to leveraging Zero-G's capabilities to pursue our common interests in space education, research, and training, especially as NASA moves to privatize its own microgravity aircraft program."

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New Coleman Solar Chargers With Cabela's

New Coleman Solar Chargers With Cabela's

ICP Solar To launch New Coleman Solar Chargers With Cabela's

ICP Solar Technologies announced that it has re-acquired Cabela's, the world's foremost outfitter for outdoor sports, as a distribution partner for its superior range of Coleman branded solar chargers. "Our thin-film solar chargers are designed to outperform similarly labelled unbranded models by up to 50%. The return of the Cabela's account is a milestone for ICP Solar and our new business development team, said Sass Peress, ceo and chairman of ICP Solar.
"We have great expectations of this relationship and are committed to improving the range of Coleman-branded products addressing their consumers. Hunters, fishermen and other outdoor sportspeople will now have access to higher quality solar chargers and we are confident we can grow Cabela's business in this area through our joint marketing efforts".

"Since joining ICP Solar in June of this year, I am proud of the additional listings that our new sales team has acquired for the upcoming season. It is validation of our strategy to consistently deliver superior, branded products in an area of the marketplace laden with underperforming products. This particular partnership is a key component of our desire to address various levels and types of distribution channels in the solar products arena, with our unique approach centered on our distribution partners' specific needs", said Tom Clark, VP Sales- Consumer Products, North America for ICP Solar.

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Missing black holes found

Missing black holes found

A new study of galaxies has unmasked hundreds of black holes hiding deep inside dusty galaxies billions of light-years away.

The massive, growing black holes, discovered by NASA's Spitzer and Chandra space telescopes, represent a large fraction of a long-sought missing population. Their discovery implies there were hundreds of millions of additional black holes growing in our young universe, more than doubling the total amount known at that distance.

"Active, supermassive black holes were everywhere in the early universe," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. and co-author. "We had seen the tip of the iceberg before in our search for these objects. Now, we can see the iceberg itself." Emanuele Daddi of the Commissariat l'Energie Atomique in France led the research.

The findings are also the first direct evidence that most, if not all, massive galaxies in the distant universe spent their youths building monstrous black holes at their cores.

For decades, a large population of active black holes has been considered missing. These highly energetic structures belong to a class of black holes called quasars. A quasar consists of a doughnut-shaped cloud of gas and dust that surrounds and feeds a budding supermassive black hole. As the gas and dust are devoured by the black hole, they heat up and shoot out X-rays. Those X-rays can be detected as a general glow in space, but often the quasars themselves can't be seen directly because dust and gas blocks them from our view.

"We knew from other studies from about 30 years ago that there must be more quasars in the universe, but we didn't know where to find them until now," said Daddi.

Daddi and his team initially set out to study 1,000 dusty, massive galaxies that are busy making stars and were thought to lack quasars. The galaxies are about the same mass as our own spiral Milky Way galaxy, but irregular in shape. At 9 to 11 billion light-years away, they existed at a time when the universe was in its adolescence, between 2.5 and 4.5 billion years old.

When the astronomers peered more closely at the galaxies with Spitzer's infrared eyes, they noticed that about 200 of the galaxies gave off an unusual amount of infrared light. X-ray data from Chandra, and a technique called "stacking," revealed the galaxies were hiding plump quasars inside. The scientists now think that the quasars heat the dust in their surrounding doughnut clouds, releasing the excess infrared light.

"We found most of the population of hidden quasars in the early universe," said Daddi. Previously, only the most rare and most energetic of these hidden black holes had been seen at this early epoch.

The newfound quasars are helping answer fundamental questions about how massive galaxies evolve. For instance, astronomers have learned that most massive galaxies steadily build up their stars and black holes simultaneously until they get too big and their black holes suppress star formation.

The observations also suggest that collisions between galaxies might not play as large a role in galaxy evolution as previously believed. "Theorists thought that mergers between galaxies were required to initiate this quasar activity, but we now see that quasars can be active in unharassed galaxies," said co-author David Alexander of Durham University, United Kingdom.

The new observations were made as part of the Great Observatories Origins Deep Survey, the most sensitive survey to date of the distant universe at multiple wavelengths.

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Personality and blood types

Personality and blood types

You're probably all too familiar with the widely recognized correlation between the stars and our lives and character traits. Interestingly, the stars are not the only place people look for that same information. In fact, a popular belief in Japan is that our personality, temperament and compatibility with others is determined, or greatly influenced, by our ABO blood type.

It's not uncommon to find blood-type 'horoscopes' and compatibility tests in the Japanese media, in much the same way that astrology has become a widely visible phenomenon in the western media. Of course, the big question is, "Is there any truth or basis to the system?"

It all began with the discovery of blood types in 1901, and in the following years, the distribution of different blood types across the globe was widely studied. While the discovery was a major leap forward in medical science, blood type statistics were often used to fuel generalizations about entire races, even being cited by Nazi Germany as an argument for 'race supremacy'. As medical science advanced, however, these beliefs became less and less popular, until they were more or less forgotten.

The idea cropped up again in Japan in the 1970's, though in a much less threatening way. Japanese journalist and author Masahiko Nomi wrote many best-selling books on the subject, proposing that there is indeed a correlation between blood type and personality, and that people of each personality type (A, B, AB and O) interact with each other in different ways. The idea spread throughout the media, and became widely popular, partly due to the natural curiosity people have to learn about themselves and their compatibility with others.

Type A's are thought to be reserved, introverted, patient and meticulous, though stubborn and self-conscious. B's are thought to be creative, passionate and optimistic, though irresponsible. AB's are considered rational, sociable and popular, though critical and unforgiving. Finally, O's are thought to be natural leaders, ambitious, self-confident, though insensitive and arrogant.

Is there science to back it up? The scientific community widely regards 'blood-type personality theory' as mere superstition, or pseudoscience, though blood-type does, naturally, have a minor effect on a person's physiology. Whether or not this influences personality is uncertain, and of course even if it does, it may simply be one of many factors playing a small contributing role. The one thing we do know is that enough people believe in it for it to remain a widely publicized and talked about phenomenon.

Perhaps the biggest down side to the system is that it is extremely general. With only four 'types', each one must be general enough to apply to an entire quarter of the population. This also means that, even if the system was completely random, 1 in 4 people would still have a personality which matches their blood-type's description, and that's more than enough people to keep any belief system alive. It's naturally very difficult to prove or disprove a system which has statistics like that. Why not compare your friends' and family's blood types, and make up your own mind?

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Single Nanotube Makes World's Smallest Radio

Single Nanotube Makes World's Smallest Radio

Over the past century, radio has shrunk dramatically from the wooden 'cathedral' style radios of the 1930s to the pocket-sized transistor radios of the 1950s and more recently to the single-chip radios found in cell phones and wireless sensors. Continuing this trend, we have further miniaturized the radio by cleverly implementing multiple radio functions with a single component, the carbon nanotube. This nanotube radio is over nineteen orders-of-magnitude smaller than the Philco vacuum tube radio from the 1930s!

Physicists at the University of California, Berkeley, have built the smallest radio yet - a single carbon nanotube one ten-thousandth the diameter of a human hair that requires only a battery and earphones to tune in to your favorite station.

The scientists successfully received their first FM broadcast last year - Derek & The Dominos' 'Layla' and the Beach Boys' 'Good Vibrations' transmitted from across the room. In homage to last year's 100th anniversary of the first voice and music radio transmission, they also transmitted and successfully tuned in to the first music piece broadcast in 1906, the 'Largo' from George Frederic Handel's opera 'Xerxes.'

'We were just in ecstasy when this worked,' said team leader Alex Zettl, UC Berkeley professor of physics. 'It was fantastic.'

The nanoradio, which is currently configured as a receiver but could also work as a transmitter, is 100 billion times smaller than the first commercial radios, and could be used in any number of applications - from cell phones to microscopic devices that sense the environment and relay information via radio signals, Zettl said. Because it is extremely energy efficient, it would integrate well with microelectronic circuits.

'The nanotube radio may lead to radical new applications, such as radio-controlled devices small enough to exist in a human's bloodstream,' the authors wrote in a paper published online today (Wednesday, Oct. 31) by the journal Nano Letters. The paper will appear in the print edition of Nano Letters later in November.

Authors of the nanoradio paper are Zettl, graduate student Kenneth Jensen, and their colleagues in UC Berkeley's Center of Integrated Nanomechanical Systems (COINS) and in the Materials Sciences Division at Lawrence Berkeley National Laboratory (LBNL). COINS is a Nanoscale Science and Engineering Research Center supported by the National Science Foundation (NSF).

Nanotubes are rolled-up sheets of interlocked carbon atoms that form a tube so strong that some scientists have suggested using a nanotube wire to tether satellites in a fixed position above Earth. The nanotubes also exhibit unusual electronic properties because of their size, which, for the nanotubes used in the radio receiver, are about 10 nanometers in diameter and several hundred nanometers long. A nanometer is one billionth of a meter; a human hair is about 50,000-100,000 nanometers in diameter.

In the nanoradio, a single carbon nanotube works as an all-in-one antenna, tuner, amplifier and demodulator for both AM and FM. These are separate components in a standard radio. A demodulator removes the AM or FM carrier frequency, which is in the kiloHertz and megaHertz range, respectively, to retrieve the lower frequency broadcast information.

The nanoradio detects radio signals in a radically new way - it vibrates thousands to millions of times per second in tune with the radio wave. This makes it a true nanoelectromechanical device, dubbed NEMS, that integrates the mechanical and electrical properties of nanoscale materials.

In a normal radio, ambient radio waves from different transmitting stations generate small currents at different frequencies in the antenna, while a tuner selects one of these frequencies to amplify. In the nanoradio, the nanotube, as the antenna, detects radio waves mechanically by vibrating at radio frequencies. The nanotube is placed in a vacuum and hooked to a battery, which covers its tip with negatively charged electrons, and the electric field of the radio wave pushes and pulls the tip thousands to millions of times per second.

While large objects, like a stiff wire or a wooden ruler pinned at one end, vibrate at low frequencies - between tens and hundreds of times per second - the tiny nanotubes vibrate at high frequencies ranging from kiloHertz (thousands of times per second) to hundreds of megaHertz (100 million times per second). Thus, a single nanotube naturally selects only one frequency.

Although it might seem that the vibrating nanotube yields a 'one station' radio, the tension on the nanotube also influences its natural vibration frequency, just as the tension on a guitar string fine tunes its pitch. As a result, the physicists can tune in a desired frequency or station by 'pulling' on the free tip of the nanotube with a positively charged electrode. This electrode also turns the nanotube into an amplifier. The voltage is high enough to pull electrons off the tip of the nanotube and, because the nanotube is simultaneously vibrating, the electron current from the tip is an amplified version of the incoming radio signal. This is similar to the field-emission amplification of old vacuum tube amplifiers used in early radios and televisions, Zettl said. The amplified output of this simple nanotube device is enough to drive a very sensitive earphone.

Finally, the field-emission and vibration together also demodulate the signal.

'I hate to sound like I'm selling a Ginsu knife - But wait, there's more! It also slices and dices! - but this one nanotube does everything; it performs all radio functions simultaneously and extremely efficiently,' Zettl said. 'It's ridiculously simple - that's the beauty of it.'

Zettl's team assembles the nanoradios very simply, too. From nanotubes copiously produced in a carbon arc, they glue several to a fixed electrode. In a vacuum, they bring the electrode within a few microns of a second electrode, close enough for electrons to jump to it from the closest nanotube and create an electrical circuit. To achieve the desired length of the active nanotube, the team first runs a large current through the nanotube to the second electrode, which makes carbon atoms jump off the tip of the nanotube, trimming it down to size for operation within a particular frequency band. Connect a battery and earphones, and voila!

Reception by the initial radios is scratchy, which Zettl attributes in part to insufficient vacuum. In future nanoradios, a better vacuum can be obtained by insuring a cleaner environment, or perhaps by encasing the single nanotube inside a second, larger non-conducting nanotube, thereby retaining the nanoscale.

Zettl won't only be tuning in to oldies stations with his nanoradio. Because the radio static is actually the sound of atoms jumping on and off the tip of the nanotube, he hopes to use the nanoradio to sense the identity of atoms or even measure their masses, which is done today by cumbersome large mass spectrometers.

Coauthors with Jensen and Zettl are UC Berkeley post-doctoral fellow Jeff Weldon and physics graduate student Henry Garcia. The work was supported by NSF and the U.S. Department of Energy.

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Latest U.S. energy plan: Use power of oceans

Latest U.S. energy plan: Use power of oceans
Exploring ways to tap into the ocean's wind and water as alternative energy sources.

A year after a bitter congressional fight over offshore drilling for oil and gas, the Bush administration now wants to tap the ocean's winds, waves and currents as a source for alternative energy.

This time, though, environmental interests are likely allies, not vocal opponents.

The powerful Gulf Stream off Florida's coast is a primary target, with federal officials saying there is enough power there to supply a third of the Sunshine State's energy.

The federal government will entertain bids beginning this week for companies to put testing equipment like meteorological towers in the ocean waters to gather data on wind, wave or current energy.

The plans could mean that within a few years, towering wind turbines could start spinning off North Carolina's Outer Banks to harness the same gusts that have tossed ships out there for centuries.

U.S. Secretary of Interior Dirk Kempthorne on Monday said the 1.8 billion acres of the federal Outer Continental Shelf could become ''a new frontier'' for the nation's energy resources.

His remarks come a year after Congress argued over whether to open up much of the nation's federal waters to drilling for oil or gas. Those proposals, ultimately shot down, brought strong opposition from environmental groups and some state governments.

But now, the administration has found some common ground with environmental groups in the push for wind- and water-generated energy.

''We wouldn't give blanket approval for these things, but the bar would have to be high for us to reject it,'' said Josh Dorner, a spokesman for the Sierra Club in Washington. ``There's a lot of wind offshore. Finding ways to tap that would be excellent.''

The Department of Interior chief said most of the potential for sub-surface current energy can be found in the Gulf Stream flowing northward off Florida's East Coast. There, capturing just one-thousandth of the Gulf Stream's energy could supply a third of Florida's energy, Kempthorne said.


Research already is under way in Florida to use the ocean waters for energy. Florida Atlantic University, which has established an ocean energy technology center, hopes to drop a prototype turbine in the Gulf Stream by early next year to measure the feasibility and environmental effects of the project.

''We're hoping to make ocean energy a baseline power source for Florida,'' said Gabriel Alsenas, an ocean engineer at FAU.

Environmentalists said they view the emerging technology as ``very promising.''

''We're certainly more excited about Interior exploring those energy sources than the same old drill anywhere and everywhere,'' said Mark Ferrulo, director of Environment Florida.

In Key West, the recently founded Florida Keys Hydro Power Research Corp. is looking at ways to build an underwater tidal turbine farm off the coast.

The Department of Interior is farthest along in understanding how to capture wind energy, Kempthorne said.

The agency, which governs federal lands, figures 70 percent of the ocean's wind power could be found in the Mid-Atlantic states in water less than 60 meters deep.

From Delaware to North Carolina, experts think they can harness enough of the south and southwesterly prevailing winds to supply energy for 50 million homes.

The sight of rows of spinning wind turbines has become a common one in flat, blustery locales like Oklahoma and parts of California. If the Interior's plan comes to fruition, such a sight could be seen offshore as well.

''Wind is a lot steadier and stronger offshore,'' Dorner said. ``You can put some really massive turbines out there.''

Federal waters of the Outer Continental Shelf begin at three miles offshore and run to 200 nautical miles, and placement of wind turbines would depend on a variety of factors, including wind resources and environmental impacts.

National parks and historical sites would be off-limits, as would some fisheries.

It's unclear how much say individual states would have on the placement of offshore energy facilities in federal waters.


Randall Luthi, director of the U.S. Minerals Management Service, said states would be consulted, but he said the Interior Department wouldn't know until next spring, when it issues its final rule on offshore wind energy, just how states might be involved in the decisions.

''As a rule, we've been very cautious about moving against a strong state interest,'' Luthi said.

The agency issued an environmental impact statement on its alternative energy plan Monday. The report, about 1,500 pages, details potential resources and the possible environmental effects that energy facilities would have around the country.

Other parts of the country have different potential energy sources.

Wave energy is possible on the Pacific Coast, between Washington and northern California, Interior officials said Monday.

If just 15 percent of the nation's wave energy were harvested, Kempthorne said, 22 million homes could be supplied with energy.

Miami Herald staff writers Evan S. Benn in Miami and Lesley Clark in Washington as well as Raleigh News & Observer staff writer John Murawski contributed to this report.

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Strong Server Sales Lift Sun to Profitable Q1

Sun Microsystems reported net income of US$89 million on strong hardware sales for its first quarter of fiscal 2008, with the company posting its fourth consecutive profitable quarter after several years of financial loss and instability.

Total revenue for the first quarter, which ended Sept. 30, was $3.22 billion, an increase of about 1 percent compared with the $3.19 billion in revenue reported for the same period last year, when the company reported a net loss of $56 million.

The quarter was profitable even with a restructuring charge of $113 million, or $0.03 per share; however, the company slightly missed analysts' estimates for revenue. Analysts polled by Thomson Financial expected the company to report $3.27 billion in revenue for the first quarter.

Earnings per share (EPS) for the quarter were $0.03, compared to a loss of $0.02 per share for the same period last year. Sun's EPS results were in line with Thomson analysts' estimates. Cash generated from operations for the quarter was $574 million and the company's cash and marketable debt securities balance was $5.193 billion at the end of the quarter, the company said.

Once thought to be in danger of being acquired or losing its position as a thought leader in the technology industry, Sun's been making a slow but apparently steady comeback since CEO Jonathan Schwartz took over as CEO from Chairman Scott McNealy a little more than 18 months ago.

In the past two years, the company has let go of some of the proprietary strategies that were keeping it down, open-sourcing both its Solaris operating system and Java development technology and embracing industry-standard processors from Intel and Advanced Micro Devices in favor of its own chips for its hardware products. The company also began selling software on a subscription basis, a move that gave a boost to its flagging Java-based software business.

Schwartz also enacted changes to make Sun more operationally efficient, as the high cost of operations was cited as a reason the company failed to turn a profit for several years. Sun cut about 4,000 employees in the past year and also instituted some internal policies to cut costs.

As a result of these changes, Sun's server business is on an upswing, and the company is also reporting greater adoption of Solaris, which took a major hit several years ago due to pressure from Linux. Sun's software subscriptions also are contributing to its overall profits; according to a press statement issued Monday, Sun's identity management software made a particularly strong showing in the quarter.

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Magnetic cocoons power energetic cosmic rays

Jets of high-speed particles stab out from a supermassive black hole at the heart of an active galaxy. The jets carve out giant, magnetised cocoons of plasma that can boost cosmic rays to improbably high speeds (Illustration: NASA)

Vast magnetic cocoons associated with galaxies whose black holes have stopped eating may be responsible for accelerating charged particles called cosmic rays to within a whisker of the speed of light.
It could explain one of the great mysteries of astrophysics – how enormously energetic cosmic rays make it to Earth, when common sense says they should long ago have run out of steam.
Cosmic rays are high-speed atomic nuclei, most commonly of hydrogen. Most come from objects within our galaxy, such as supernova remnants and pulsars.
But ultra-high-energy cosmic rays (UHECRs) – each packing the punch of a baseball – are an outstanding mystery. Although it is conceivable that they are produced near the Milky Way by the decay of super-heavy dark matter particles or by defects in space-time, the most likely sources are the most powerful objects in the universe – 'active' galaxies whose colossal black holes are devouring nearby matter, and gamma-ray bursts. These are far beyond our galaxy – and herein lies a very serious problem.
The problem arises because every cubic centimetre of space contains about 400 relic photons from the big bang fireball. They have little energy, but seen from the point of view of a speeding cosmic ray, they are enormously boosted in energy, becoming high-energy gamma rays. The interaction of cosmic rays with these gamma rays continually saps the very highest energy cosmic rays of energy. Therefore, we should detect none of them on Earth – but we do.
Gregory Benford of the University of California in Irvine, US, and Raymond Protheroe of the University of Adelaide in Australia have a solution.
Magnetised cocoonsThey point out that a few per cent of the volume of the universe is filled by giant magnetised cocoons of plasma, or charged particles. These were carved out by "jets" stabbing out from the supermassive black holes at the heart of active galaxies.
"These colossal magnetic structures persist even when the galaxies have ceased their activity," says Protheroe. "And they store truly vast amounts of energy in their fields."
Benford and Protheroe point out that over billions of years, the slow decay of the magnetic fields inside such fossil cocoons induces an electric field. "These electric fields are strong enough to accelerate cosmic rays to ultra-high energies," says Protheroe.
UHECRs on their journey to Earth pass through many such cocoons. "And the electric fields can repeatedly boost the energy, counteracting the effect of big bang photons," says Benford. "Contrary to expectations, ultra-high-energy cosmic rays can make it to Earth."
Others think the mechanism is intriguing. "Given what we know now, I think [decaying magnetic fields] are the least implausible explanation of ultra-high energy cosmic rays," says Roger Blandford of Stanford University in California, US.

Technology and global prospect : Technology market is breaking the general economy structure

The imbalaced growth of technology market is breaking the general economy structure of world .
For the seek of humanity , I personally suggest to find out the way of a balanced life ... live and next world .
I agree the research of NASA , but i never agree the proverty of Human in world.
pls watch from micro eye,
Considering as a big platform , i simply will happy if you innitiate to find out the happy world for all and for honeymoon ......... space may be the best choice.

Controls :Technology tunes into our emotions

Technology can do many thing ...........something already reached in success ,something on the way. where is the end ?

Technology tunes into our emotions
A technology that can recognise anxiety in people is being developed by an Australian computer scientist.
Australian National University researcher Gordon McIntyre says the technology could be applied in a range of areas from aged care to driver safety.
McIntyre, a PhD student from the Research School of Information Services and Engineering, is working on a computer system that detects anxiety by analysing a person's speech and facial expressions.
Changes in speech rhythm and pitch and any quavering in the voice are picked up by speech recognition software.
While changes in facial expressions are tracked using artificial neural networks, which mimic how the brain processes information.
In developing the project, McIntyre plotted 65 landscape points on the face that change during various emotional states, such as the eyebrows, lips and nose.
The computer determines emotions by measuring changes in the location of these landscape points compared to an average or expression-free face.
McIntyre says work by body language scientists such as the University of California, San Francisco's Professor Emeritus Paul Ekman, suggests an anxious face will often show contracting eyebrows, a tightening of the upper lip and a deepening of the furrow between the nose and lips.
"We build up an average shape of a face from a database," McIntyre says. "And then measure the difference between an average face and one that is subject to the emotion."
Two types of anxiety
McIntyre, who is working with psychology colleagues to develop the program, says there are two types of anxiety.
Long-term anxiety is more easily recognised via facial expressions, while short-term anxiety is revealed through speech.
One of his major hurdles is the lack of anxious face samples from which to develop a template image of the emotion.
McIntyre plans to create his own database with the help of ANU's School of Psychology.
He hopes to run a series of experiments next year where anxiety will be induced in participants through computer games or dialogue.
Their speech and faces will be recorded for inclusion in McIntyre's database.
According to McIntyre, Australian Bureau of Statistics data show one in every 10 Australians suffers from an anxiety disorder.
He says a computer that can detect anxiety could be used to help train medical practitioners to recognise the condition and to monitor patients not able to communicate their needs clearly.
"The important thing is to get something working to show people what can be done and then let them look at the situations where it might fit," he says.

Tiny sensor measures tiny magnetic fields

A magnetic sensor smaller than a grain of rice and sensitive enough to detect the brainwave of someone daydreaming has been developed by US scientists who say their research offers the potential for a host of new medical and security uses.
They says the sensor, described online in the journal Nature Photonics, provides a low-cost and portable way to detect changes in a magnetic field.
"What we've done is demonstrate a very good sensitivity with a very small cell," says Dr John Kitching of the US National Institute of Standards and Technology (NIST), who led the project.
The researchers say it's 1000 times more sensitive than NIST's last microchip-sized mini-sensor and can detect magnetic fields down to 70 femtoteslas.
The latest sensor is just a prototype, but Kitching says the device could be used in a range of applications, from foetal heart monitoring to screening for explosives.
Because of its small size, he says it could run for several weeks on a single AA battery.
"Magnetic fields are all over the place," Kitching says. "Anything that has iron in it has a magnetic field."
Electric currents, such as those from power lines, emit a magnetic field, as do the electrical impulses that make the heart contract or brain cells fire.
Larger magnetometers are used by geologists to find iron deposits and by archaeologists to find buried objects. They can also be used by satellites to track the earth's magnetic field.
The most sensitive magnetic sensors - superconducting quantum interference devices or SQUIDS - can detect very weak changes in magnetic fields but must be kept very cold, making them much bigger and far more power-hungry.
While the NIST device sacrifices a bit of that sensitivity, it makes up for it in portability.
"We are able to make something that is almost as sensitive without all the stuff that is needed to make it run," Kitching says.
The prototype consists of a tiny container holding about 100 billion atoms of rubidium.
The researchers shoot an infrared laser beam through the container and measure how much light the atoms absorb. The higher the absorption, the stronger the magnetic field.
Kitching says the device is highly adaptable. It could be used to measure electrical activity in the brain, helping to spot tumours or monitor brain function. Or it could be used in war zones to detect bombs that may not have exploded.
"It really does open up a wide range of possibilities," he says.

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