Free Republic

Astronomers have been so horrified by press scares over asteroids that they are toning down the scale they use to rate the threat posed in an attempt to discourage journalists from covering potential collisions. The most prominent recent furore involved asteroid QQ47, which briefly had a one-in-a-million chance of crashing into our planet in 2014. Some astronomers even want the way asteroids are assessed to be completely overhauled. The Torino scale, developed in 1999 by Rick Binzel of the Massachusetts Institute of Technology, is used to inform the public about potential impacts. It rates an asteroid's threat on a scale...

The first humans to arrive on the Indian subcontinent from Africa about 65,000 years ago left a genetic imprint that can still be found in the tribes of India... "Whether the original inhabitants of India were replaced by more modern immigrants or contributed to the contemporary gene pool has been debated," says Michael Bamshad of the University of Washington in Seattle, who has studied the genetic diversity of India. One way researchers have used to figure this out is to use linguistic groups. The tribes speaking Indo-European languages, for instance, are known to be descendants of the people who migrated...

In its 2007 report, the Intergovernmental Panel on Climate Change (IPCC) forecast a sea level rise of between 19 and 59 centimetres by 2100, but this excluded "future rapid dynamical changes in ice flow". "Larger rises cannot be excluded but understanding of these effects is too limited to assess their likelihood," the IPCC report stated. Even before it was released, the report was outdated. Researchers now know far more. And while we still don't understand the dynamics of ice sheets and glaciers well enough to make precise predictions, we are narrowing down the possibilities. The good news is that some...

Surrounding city centres and likely terrorist targets with "soft walls" will make it impossible for hijacked planes to get anywhere near them. So say the inventors of an avionics system that creates no-fly zones that pilots cannot breach. Since the terrorist attacks on 11 September 2001, anti-aircraft missile batteries have been installed to protect buildings in Washington DC and other US cities. Less drastic solutions have also been suggested. Aerospace company Northrop Grumman, for instance, has proposed installing the electronics from its Global Hawk pilotless plane in passenger aircraft to allow ground control to take over a hijacked plane and...

It¹s not love, affection or even blatant self-interest that binds human societies together - it's anger, according to Swiss researchers. They made the unsettling discovery while trying to fathom what makes people cooperate. Traditional explanations, such as kinship and reciprocal altruism, rely on genetic relationships or self-interest. These work for animals, but fail for humans because people cooperate with strangers they may never meet again, and when the pay-off is not obvious. Such cooperation can be explained if punishment of freeloaders or "free-riders" - those who do not contribute to a group but benefit from it - is taken into ...

ON THE night of 30 June 2005, the sky high above La Palma in Spain's Canary Islands crackled with streaks of blue light too faint for humans to see. Atop the Roque de los Muchachos, the highest point of the island, though, a powerful magic eye was waiting and watching. MAGIC - the Major Atmospheric Gamma-ray Imaging Cherenkov Telescope - scans the sky each night for high-energy photons from the distant cosmos. Most nights, nothing remarkable comes. But every now and again, a brief flash of energetic light bears witness to the violent convulsions of a faraway galaxy. What MAGIC...

Early humans swapped bite for brain 18:00 24 March 04 NewScientist.com news service Humans owe their big brains and sophisticated culture to a single genetic mutation that weakened our jaw muscles about 2.4 million years ago, a new study suggests. The slack muscles relaxed their hold on the human skull, giving the brain room to grow. Other primates remained stuck with mighty muscles that squeezed the skull in a vice-like grip. The finding is "pretty amazing", says Peter Currie, an expert on skeletal muscle development at the Victor Chang Cardiac Research Institute in Darlinghurst, Australia: "Changes in muscle anatomy are...

An electromagnetic "black holeMovie Camera" that sucks in surrounding light has been built for the first time. The device, which works at microwave frequencies, may soon be extended to trap visible light, leading to an entirely new way of harvesting solar energy to generate electricity. A theoretical design for a table-top black hole to trap light was proposed in a paper published earlier this year by Evgenii Narimanov and Alexander Kildishev of Purdue University in West Lafayette, Indiana. Their idea was to mimic the properties of a cosmological black hole, whose intense gravity bends the surrounding space-time, causing any nearby...

POSSIBLY the clearest skies on Earth have been found - but to exploit them, astronomers will have to set up a telescope in one of the planet's harshest climates...[Scientists] evaluated different factors that affect telescope vision, such as the amount of water vapour, wind speeds and atmospheric turbulence...The team found that the Antarctic plateau offers world-beating atmospheric conditions - as long as telescopes are raised 20 meters above its frozen surface...[The Antarctic air is] drier than the Atacama desert in Chile [where some of the best telescopes in the world are currently located].

How our youthful universe explored the string-theory multiverse in search of home—with help from its anti-universe counterpart. Its journey could explain why our cosmos is so well suited for life.Saswat Sarangi owes his career in physics to a twist of fate. When he was a 13 year-old schoolboy in Orissa in eastern India, his uncle bought him a copy of Stephen Hawking’s A Brief History of Time as a birthday present. Unfortunately, the young Sarangi would have preferred a cricket bat, and the book remained unread for two years, until he found himself struggling to prepare for a physics test...

BRIAN GREENE spent a good part of the last decade extolling the virtues of string theory. He dreamed that one day it would provide physicists with a theory of everything that would describe our universe - ours and ours alone. His bestselling book The Elegant Universe eloquently captured the quest for this ultimate theory. "But the fly in the ointment was that string theory allowed for, in principle, many universes," says Greene, who is a theoretical physicist at Columbia University in New York. In other words, string theory seems equally capable of describing universes very different from ours. Greene hoped...

BRIAN GREENE spent a good part of the last decade extolling the virtues of string theory. He dreamed that one day it would provide physicists with a theory of everything that would describe our universe - ours and ours alone. His bestselling book The Elegant Universe eloquently captured the quest for this ultimate theory. "But the fly in the ointment was that string theory allowed for, in principle, many universes," says Greene, who is a theoretical physicist at Columbia University in New York. In other words, string theory seems equally capable of describing universes very different from ours. Greene hoped...

An army of monster Wimpzillas is hiding out in our Galaxy and Earth is under attack. Fantastical as these beasts sound, they could solve two mysteries that have been plaguing physicists for years: the source of the Universe's missing mass, and the origin of the most powerful cosmic rays hitting our planet. Physicists have worked out that most matter in the Universe must be made up of "dark matter" we cannot see, otherwise galaxies wouldn't have enough gravitational pull to hold themselves together. So far, the most likely candidates for dark matter are WIMPs, or weakly interacting massive particles, that...

WE COULD be living inside a black hole. This head-spinning idea is one cosmologist's conclusion based on a modification of Einstein's equations of general relativity that changes our picture of what happens at the core of a black hole. In an analysis of the motion of particles entering a black hole, published in March, Nikodem Poplawski of Indiana University in Bloomington showed that inside each black hole there could exist another universe (Physics Letters B, DOI: 10.1016/j.physletb.2010.03.029). "Maybe the huge black holes at the centre of the Milky Way and other galaxies are bridges to different universes," Poplawski says. If...

ABHAY ASHTEKAR remembers his reaction the first time he saw the universe bounce. "I was taken aback," he says. He was watching a simulation of the universe rewind towards the big bang. Mostly the universe behaved as expected, becoming smaller and denser as the galaxies converged. But then, instead of reaching the big bang "singularity", the universe bounced and started expanding again. What on earth was happening? Ashtekar wanted to be sure of what he was seeing, so he asked his colleagues to sit on the result for six months before publishing it in 2006. And no wonder. The theory...

Physicists struggling to reconcile gravity with quantum mechanics have hailed a theory – inspired by pencil lead – that could make it all very simpleIT WAS a speech that changed the way we think of space and time. The year was 1908, and the German mathematician Hermann Minkowski had been trying to make sense of Albert Einstein's hot new idea - what we now know as special relativity - describing how things shrink as they move faster and time becomes distorted. "Henceforth space by itself and time by itself are doomed to fade into the mere shadows," Minkowski proclaimed, "and...