Close to the end of the last ice age there was a sudden disappearance of many mammalian species which some paleontologists say was the most severe since the disappearance of the dinosaurs 65 million years ago. In North America 95 percent of the megafauna became extinct, these being predominantly mammals having body weights greater than 25 to 50 kilograms. But even small animals were affected, as in the disappearance of 10 genera of birds.

Although North America was most affected, it had a severe impact also in Europe, Siberia, and South America. The cause of the extinction has long remained a mystery. Theories that have been put forth have ranged from overkill by North American paleolithic hunters to the impact of a large comet or swarm of meteors. But all have been shown to have serious flaws.

Now, Starburst Foundation researcher Dr. Paul LaViolette has found evidence that this mysterious die-off may have had a solar flare cause. In his paper published this week in the journal Radiocarbon, LaViolette concludes that a super sized solar proton event (SPE) impacted the earth about 12,900 years ago (12,837+/- 10 calendar years BP).*

He notes that this date roughly coincides with that of the Rancholabrean termination, a time boundary beyond which the numbers of extinct megafaunal remains are found to sharply decline.

Solar proton events, blasts of energetic solar cosmic ray particles that are shot out with the eruption of a solar flare, can arrive with little advance notice, traversing the 93 million mile distance from the Sun to the Earth in a matter of hours. They are usually followed some days later by a slower moving solar wind plasma shock called a coronal mass ejection.

They have been observed to occur from time to time in past decades, but none in modern times have been strong enough to pose a serious ground-level radiation hazard.

LaViolette carefully studied data spanning the onset of the Younger Dryas cold period near the end of the ice age during which there was a progressive long-term rise in the atmosphere's radiocarbon concentration.

Although some of this 14C rise was due to changes in the ocean's carbon reservoir due to deep ocean circulation, a large part of it was believed to be due to a real rise in atmospheric radiocarbon concentration.

Welcome to the Dead Zone.

I was one of the very last people to take my mobile phone onto the site which Australia and New Zealand hope will become the epicentre of the world's largest radio telescope array.

Not that my phone was very much use. You'd be better off with a carrier pigeon eight hours northeast of Perth, at a place called Boolardy Station in Murchison Shire.

There are already six radio dishes here, of a total of 36 which will form the Australian Square Kilometre Array Pathfinder. The other 30 dishes are due to be built by the end of the year.

However authorities hope the site will also become the epicentre of a much larger project - SKA, the largest array of radio telescopes ever built, with 3000 dishes stretching 5500km from Boolardy to New Zealand.

With the processing power of "about a billion PCs", the SKA hopes to play the central role in unlocking the mysteries of how our universe came into being - from the nature of gravity to the evolution of our galaxies.

On Thursday I joined a gaggle of journalists, stakeholders, indigenous leaders and CSIRO scientists - along with their video cameras, phones and digital recording devices - to visit Boolardy Station.

A team of physicists is claiming to have coaxed sparks from the vacuum of empty space.¹ If verified, the finding would be one of the most unusual experimental proofs of quantum mechanics in recent years and "a significant milestone", says John Pendry, a theoretical physicist at Imperial College London who was not involved in the study.

The researchers, based at the Chalmers University of Technology in Gothenburg, Sweden, will present their findings early next week at a workshop in Padua, Italy. They have already posted a paper on the popular pre-print server arXiv.org, but have declined to talk to reporters because the work has not yet been peer-reviewed. High-profile journals, including Nature, discourage researchers from talking to the press until their findings are ready for publication.

Nevertheless, scientists not directly connected with the group say that the result is impressive. "It is a major development," says Federico Capasso, an experimental physicist at Harvard University in Cambridge, Massachusetts, who has worked on similar quantum effects.

Antimatter, an elusive type of matter that's rare in the universe, has now been trapped for more than 16 minutes - an eternity in particle physics.

In fact, scientists who've been trapping antihydrogen atoms at the European Organization for Nuclear Research (CERN) in Geneva say isolating the exotic particles has become so routine that they expect to soon begin experiments on this rare substance.

Antimatter is like a mirror image of matter. For every matter particle (a hydrogen atom, for example), a matching antimatter particle is thought to exist (in this case, an antihydrogen atom) with the same mass, but the opposite charge.

"We've trapped antihydrogen atoms for as long as 1,000 seconds, which is forever" in the world of high-energy particle physics, said Joel Fajans, a University of California, Berkeley professor of physics who is a faculty scientist at California's Lawrence Berkeley National Laboratory and a member of the ALPHA (Antihydrogen Laser Physics Apparatus) experiment at CERN.

By gazing at the edges of sunspots, astronomers now are pinpointing key details of how these mysterious dark marks form.

Sunspots are blotches on the sun that appear dark because they are cooler than the rest of the solar surface. Astronomers do know they are linked to intense magnetic activity on the sun, which can suppress the flow of hot matter, but much about their structure and behavior remains enigmatic.

The dark heart of a sunspot, called the umbra, is surrounded by a brighter edge known as the penumbra, which is made of numerous dark and light filaments more than 1,200 miles (2,000 kilometers) long. They are relatively thin, at approximately 90 miles (150 km) in width, making it difficult to resolve details that could reveal how they arise.

Equality for men may be on the horizon, contraceptive equality, that is. For just over a half century, women have been able to pop a pill to prevent pregnancy, but a pharmaceutical alternative has never emerged for men.

Now, research to interfere with the body's ability to use vitamin A is showing some promise, because, in men, vitamin A is necessary for the production of sperm.

One recent study found that a compound that interferes with the body's ability to use vitamin A rendered male mice sterile while they were receiving 8- or 16-week courses. But once the mice were taken off the compound, they resumed making sperm. Significantly, the researchers found no side effects, and the testosterone levels of the mice stayed normal, meaning no fluctuations in mousey libido.

"Our mice, they mate quite happily, so that is not something we have interfered with," said Debra Wolgemuth, one of the study researchers and a professor of genetics and development at Columbia University Medical Center.

Scientists have discovered a genetic mutation responsible for a disorder that causes people to sprout thick hair on their faces and bodies.

Hypertrichosis, sometimes called "werewolf syndrome" is a very rare condition, with fewer than 100 cases documented worldwide. But researchers knew the disorder runs in families, and in 1995 they traced the approximate location of the mutation to a section of the X chromosome (one of the two sex chromosomes) in a Mexican family affected by hypertrichosis.

Men with the syndrome have hair covering their faces and eyelids, while women grow thick patches on their bodies. In March, a Thai girl with the condition got into the Guinness Book of World Records as the world's hairiest child.

A man in China with congenital hypertrichosis helped researchers break the case. Xue Zhang, a professor of medical genetics at the Peking Union Medical College, tested the man and his family and found an extra chunk of genes on the X chromosome. The researchers then returned to the Mexican family and also found an extra gene chunk (which was different from that of the Chinese man) in the same location of their X chromosomes.

Circling the Web this week is an incredible video showing Valerie Taylor, a world-renowned shark expert, hand-feeding a great white shark off the side of a boat. After placing a fish into the fearsome creature's mouth, she even leans down and pats it on the nose.

"I think the shark and I had an understanding," Taylor says in a voiceover of the footage, which aired in a TV documentary called Shadow of the Shark. "This one, I had a feeling for."

Great white sharks, according to Yannis Papastamatiou, a research biologist in the Florida Program for Shark Research at the Florida Museum of Natural History, are intelligent and good learners. Despite the great white's reputation as a vicious hunter, like many wild animals, with enough practice and patience (and fish), researchers can condition them to take handouts from research vessels. It isn't unheard of, Papastamatiou said, for researchers to hand-feed them.

In the video, Taylor does just that, first coaxing the shark progressively closer to the boat using line baited with fish before finally feeding the shark by hand.

While this footage might be hair-raising to most of us, it's all in a day's work for Taylor, who, along with husband Ron, has worked in close quarters with great white sharks for decades. She even once swam among great whites with tuna filets stuffed in her chainmail diving suit just to learn more about the way they bite and feed.

An international team of researchers has, for the first time, mapped complete trajectories of single photons in Young's famous double slit experiment. The finding takes an important first step towards measuring complimentary variables of a quantum system - which until now has been considered impossible as a consequence of the Heisenberg uncertainty principle.

In the double slit experiment, a beam of light is shone onto a screen through two slits, which results in an interference pattern on the screen. The paradox was that one could not tell which slit single photons had passed through, as measuring this would directly distort the interference pattern on the screen. "In most science, it is possible to look at what a system is doing presently and so, determine its past or future. But in quantum mechanics, it is considered inconceivable to consider the past at all." says physicist Aephraim Steinberg of the Centre for Quantum Information and Quantum Control at the University of Toronto, Canada who has led this new research.

Now, using a technique known as "weak measurement" Steinberg and his team say they have managed to accurately measure both position and momentum of single photons in a two-slit interferometer experiment. The work was inspired by one of Steinberg's colleagues, Howard Wiseman of Griffith University, Australia, who proposed in 2007 that it may be possible to use weak measurements to determine momenta and positions in the double slit experiment. Steinberg was immediately fascinated and began to see how this would become experimentally viable.

It has been 780,000 years since the last reversal, so we may be long overdue one. But will lethal radiation from space bombard the Earth, as it drops its protective magnetic shield during the reversal? Italian scientists studying one of the most mysterious natural phenomena say that polarity reversals seem to occur in clusters, indicating some kind of "memory" of previous events.

Scientists now say that the Earth's magnetic poles were once near the equator, which could explain puzzling changes in the magnetism of rocks millions of years ago.

The Earth's magnetic poles are aligned along roughly the same axis as its rotational poles. Geologists have assumed this was also true in the past, so they use volcanic rocks, which when they formed took on an imprint of the direction and strength of the Earth's magnetic field, to deduce the rocks' original latitude and to trace continental motions over the past billion years, which has created a puzzle for rocks in North America and eastern Europe. In both regions, there appear to be rocks that were at the equator at some points between 550 and 600 million years ago and near the poles for other parts of this time period.