Science

Scientists say curious clouds could foretell earthquakes

Sat, 12 Apr 2008 19:09:15 GMT

"Scientists say strange cloud formations could alert nations to impending earthquakes, according to a report today.

The theory comes after two distinctive cloud formations were observed above an active fault in Iran, each before two large earthquakes occurred.

According to the New Scientist, geophysicists Guangmeng Guo and Bin Wang of Nanyang Normal University in Henan, China, noticed a gap in the clouds in satellite images from December 2004 that exactly matched the location of the main fault in southern Iran.

The gap in the clouds stretched for hundreds of kilometres and was visible for several hours.

It also remained in the same place despite the clouds around it moving.

Thermal images of the ground showed that the temperature was higher along the fault.

On February 22nd 2005 - 69 days later - a 6.4 magnitude earthquake struck the area, killing 600 people.

In December 2005 a similar cloud formation was spotted and 64 days later an earthquake with a magnitude of six hit the region.

Geophysicists argue that there could be a number of reasons for the link between clouds and earthquakes.

They say that an eruption of hot gases from inside the fault could have caused water in the clouds to evaporate.

Another theory is that when rocks are squeezed, positively-charged ions form in the air above.

The cloud formations have led some to propose that they could be used for earthquake prediction.

However Mike Blanpied of the US Geological Survey's earthquake hazards programme told the New Scientist: "There is no physical model that explains why something would suddenly occur two months before an earthquake, and then shut off and not occur again."

News Source

Study: Grand Canyon 11M years older than thought

Tue, 18 Mar 2008 00:12:46 GMT

"By Lauran Neergaard, Associated Press
WASHINGTON — Gazing into the majestic Grand Canyon, awe-struck visitors inevitably ask: "How old is it?"

Far older than generally thought, says new evidence that scientists culled from caves lining the canyon's red limestone cliffs.

The Grand Canyon often is referred to as about 6 million years old — but its western half actually began to open at least 17 million years ago, a University of New Mexico team reports Friday in the journal Science.

Remember, geologists caution, that the Grand Canyon was carved from drainage systems that didn't turn into the single river we now know as the Colorado until roughly 6 million years ago. The new research suggests two canyons formed that eventually joined. And it makes sense that the older side would even look different, less jagged, thanks to more years of gravity and wind erosion to soften its edges.

"This is really exciting for those of us who work in the stories and theories of how the Grand Canyon has evolved," Arizona geologist Wayne Ranney, author of Carving the Grand Canyon, said of the new work. "This paper helps us to more clearly understand that different parts of the canyon formed at different times. That's how big the Grand Canyon is."

How and when the Grand Canyon formed has been a question of both geologists and average visitors since John Wesley Powell's famous first expedition in 1869.

Dating the canyon's carving has been difficult because it has largely depended on evidence from exposed rock and mineral deposits that themselves erode over time.

The University of New Mexico team tried a new technique: Testing formations inside the numerous caves that line the Grand Canyon — protected formations less susceptible to erosion — that form at the water table. So cave specialist Carol Hill said they should provide a record of how the water table dropped over time as the canyon was cut deeper and deeper.

First Hill and colleagues made the grueling climbs to cull the formations from caves in 10 different spots along the length of the Grand Canyon. Then came work in specialized labs to pin down the age of each formation, using a method called uranium-lead isotope testing.

The findings: The western side of what is now the Grand Canyon started forming about 17 million years ago, and that initial erosion was fairly slow and steady — a couple of inches every thousand years.

The canyon formed not just downward and westward but it opened steadily to the east, too, through what geologists call "headward erosion," the team reports — until the western side cut through enough rock to meet water on the eastern side, around 5 to 6 million years ago.

Then the action really started, with the eastern side of the canyon being cut at a rate of about 8 inches to almost a foot every thousand years, they report.

Why the speedup? The new research can't say exactly, but Ranney notes that land mass was shifting around a lot during this period, too, heaving some sections of rock and lowering others. The Hurricane and Toroweap faults in the western Grand Canyon dropped enough to essentially form a waterfall, speeding water flow enough that the eastern side was being ripped as the river plunged to the west, he explained.

While geologists point to some questions in the new research, overall it does fit with various theories about how the Grand Canyon formed, said Rebecca Fowler of the University of Colorado, Boulder, who also studies the Grand Canyon.

"All of it is pointing toward a pretty complex history of Grand Canyon development, which is one of the reasons this area has been so controversial," she said. "It's a pretty complicated system and it's very likely that the entire Grand Canyon did not incise (cut) all at one time." "

News Source: USA Today

Have Scientists Discovered a Way of Peering Into the Future?

Sun, 24 Feb 2008 23:22:19 GMT

"Deep in the basement of a dusty old library in Edinburgh lies a small black box that churns out random numbers. At first glance the box looks profoundly dull, but it is, in fact, the ‘eye' of a machine that appears capable of peering into the future.

The machine apparently sensed the September 11th attacks on the World Trade Centre four hours before they happened, and appeared to forewarn of the Asian Tsunami.

"It's Earth shattering stuff," says Dr Roger Nelson, Emeritus researcher at Princeton University in the USA. "But unfortunately we don't have a box for predicting the future that we can sell to the CIA. We're very early on in the process of trying to figure out what's going on here. At the moment we're stabbing in the dark."

Dr Nelson's Global Consciousness Project - originally hosted by Princeton University - is one of the most extraordinary experiments of all time. It aims to ‘sense' whether all of humanity shares a single unconscious mind that we all tap into without realising it. Some might refer to it as the mind of God. But the machine has also thrown up another tantalising possibility: that scientists may have unwittingly discovered a way of predicting the future.

Although many would consider the project's aims to be little more than fools' gold, it has still attracted a roster of 75 respected scientists from 41 different nations. Researchers from Princeton - where Einstein spent much of his career - work alongside scientists from universities in Britain, Holland, Switzerland and Germany. The project is also the most rigorous and longest running investigation ever into the paranormal.

"Very often paranormal phenomena evaporate if you study them for long enough," says physicist Dick Bierman of the University of Amsterdam. "But this is not happening with the Global Consciousness Project. The effect is real. The only dispute is about what it means."

The project has its roots in the extraordinary work of Professor Robert Jahn of Princeton University during the late 1970s. Professor Jahn was one of the first modern scientists to take paranormal phenomena seriously. Intrigued by such things as telepathy, telekinesis and ESP, he was determined to study the phenomena using the most up to date technology available.

One of these new technologies was a humble looking black box known was a Random Event Generator. This used sophisticated technology to generate two numbers - a one and a zero - in a totally random sequence, rather like an electronic coin-flipper. The pattern of ones and noughts - ‘heads' and ‘tails' as it were - can then be printed out as a graph. Pure chance dictates that the generators should churn out equal numbers of ones and zeros which produces a more or less flat line on a graph. Any deviation from this shows up as a gently rising curve.

During the late 1970s, Professor Jahn hauled strangers off the street and asked them to concentrate their minds on a number generator. In effect, he was asking them to try to make it flip more heads than tails. It was a preposterous idea at the time, and to many it still is.

The results, however, were stunning and have never been satisfactorily explained. Again and again, entirely ordinary people proved that their minds could influence the machines and produce significant fluctuations on the graph. According to all of the known laws of science, this should not have happened - but it did. And it kept on happening.

Dr Roger Nelson, also working at Princeton University, then extended Professor Jahn's work by taking the machines to group meditations, which were very popular in America at the time. Again, the results were shocking. The meditators somehow caused dramatic shifts in the numbers.

From then on, Dr Nelson was hooked. Using the Internet, he connected up 40 random event generators from all over the world to his laboratory computer in Princeton. These ran day in day out, generating millions of different pieces of data. Most of the time, the resulting graph on his computer looked more or less like a flat line. But during the funeral of Princess Diana something extraordinary happened: the graph shot upwards and reached for the sky. It was clear that they'd detected a totally new phenomena. The concentrated mental effort of millions of people appeared to be influencing the output of random event generators around the world. But how? Dr Nelson was still at a loss to explain it.

In 1998 he gathered together scientists from all over the world to try and understand the phenomena. They, too, were stumped and resolved to extend and deepen Jahn and Nelson's work. The Global Consciousness Project was born.

Since then, the project has expanded massively. A total of 65 Eggs (as the generators have been named) in 41 countries have now been recruited to act as the ‘eyes' of the project. And the results have been startling and inexplicable in equal measure. The Eggs not only ‘sensed' the moment that Princess Diana was buried, but also the NATO bombing of Yugoslavia, the Kursk tragedy and America's hung election of 2000. The Eggs also regularly detect huge global celebrations such as New Year's Eve. Even more bizarrely, they sense the celebrations as they sweep through the Earth's different time zones.

The project threw up its greatest enigma on September 11th 2001. As the world stood still and watched the horror of the terrorist attacks unfold across New York, something strange was happening to the Eggs. Not only did they register the event as it happened, but the characteristic shift in the pattern of numbers began four hours before the two planes hit the Twin Towers.

"I knew then that we had a great deal of work ahead of us," says Dr Nelson.

The same happened with the Asian Tsunami. Twenty four hours before the tragedy unfolded, the characteristic shift in the pattern of numbers began. Curiously, it was at around this time that animals in the path of the tsunami began fleeing for their lives. Very few animals were killed in the tragedy, as you may remember, leading some to ask whether they had somehow foreseen the disaster.

So does the Global Consciousness Project really forecast the future? After all, cynics will quite rightly say that if you look at enough data then you will find correlations with something. After all, our world is full of wars, disasters and terrorist outrages, as well as the occasional global celebration.

The team behind the project say that they've thought of this. Using rigorous scientific techniques and powerful mathematics it is possible to exclude these chance connections. And they believe they have done so.

"Good scientists will ask what mistakes we've made," says Dr Nelson. "We're perfectly willing to discover that we've made mistakes. But we haven't been able to find any, and neither has anyone else.

"Our data shows clearly that the chances of getting these results by chance are one million to one against. That's hugely significant."

The Global Consciousness Project may have generated an incredible amount of compelling evidence, and garnered the support of eminent scientists, but many remain sceptical.

Professor Chris French, a psychologist and noted sceptic at Goldsmiths College in London, says: "The project has generated some very intriguing results that cannot be readily dismissed. I'm involved in similar work to see if we get the same results. We haven't managed to do so yet but it's only an early experiment. The jury's still out."

Strange as it may seem, there's nothing in the laws of physics that precludes the possibility of foreseeing the future. Time may not just move forwards - but backwards too. And if time ebbs and flows like the tides in the sea, it might just be possible to foretell the future.

"There's plenty of evidence that time may run backwards," says Professor Dick Bierman, a physicist at the University of Amsterdam. "And if it's possible for it to happen in physics then it can happen inside our heads too."

As a consequence says Professor Bierman, forecasting the future may not just be possible - it's something we do routinely without even realising it.

Dr John Hartwell, working at the University of Utrecht in the Netherlands, was the first to uncover evidence that people could sense the future. In the mid 1970s he hooked people up to hospital EEG machines so that he could study their brainwave patterns. When these people were shown emotionally charged cartoons, characteristic patterns flickered through their brainwaves. Strangely, these patterns began to emerge a few seconds before they actually saw the pictures.

But it was to be another 15 years before anyone else took this work further. Dean Radin, working in America, connected people up to a machine that measured their skin's resistance to electricity. This is known to fluctuate in tandem with our moods, indeed, it's this principle that underlies many lie detectors. Radin repeated Dr Hall's work whilst measuring skin resistance. Again, people began reacting a few seconds before they were shown the pictures. This was clearly impossible, or so he thought, so he kept on repeating the experiments and getting the same results.

"I didn't believe it," says Professor Bierman. "So I repeated the experiment myself and got the same results. I was shocked. After this I started to think more deeply about the nature of time."

Bierman then devised an experiment to settle his mind once and for all. He decided to use a hospital brain scanner to peer inside people's minds as they were shown a series of photographs. Each person was randomly shown erotic or violent pictures, or neutral images of white fluffy clouds. Each of these pictures produced unique patterns in the patient's brainwaves. In effect, you could see inside the mind as it reacted to each picture.

What is remarkable is that the patients began reacting 1-2 seconds before they saw the images. This is clearly impossible, or so we're taught to believe. And yet it happened time and time again.

Obviously sceptics would love to demolish Bierman's work but have so far failed to do so. Nor is his research a one off that can be casually dismissed. To make matters even more intriguing, Bierman says that other mainstream labs have produced similar results but they are too frightened to go public.

"They don't want to be ridiculed so they won't release their findings, says Professor Bierman. "So I'm trying to persuade all of them to release their results together. That would at least spread the ridicule a little more thinly!" jokes the Professor.

If Bierman is right, then sensing the future may help explain such things as deja vu, intuition and a host of other paranormal phenomena. It may also open up a far more interesting possibility - enhancing psychic powers using machines. Just as we have built machines to replace muscle power, may we one day build a device to enhance psychic abilities?

Dr Nelson is optimistic - but not for the short term: "We may be able to predict that something is going to happen. But we won't know exactly what will happen or where it's going to happen," he says.

But for Dr Nelson, talk of psychic machines is of far less importance than the implications of his work for ordinary people. We may all be individuals, he says, but we are also part of something far, far greater.

"We're taught to be individualistic monsters," he says. "We're driven by society to separate ourselves from each other. That's not right. We may be connected together far more intimately than we realise."

News Source: News Monster

Time Machine to Be Created?

Mon, 11 Feb 2008 20:30:06 GMT

"The stream of stories about the Large Hadron Collider's operation is getting genuinely weird. Nineteen-sixties, little-green-monster, B-movie sci-fi weird. Not, mind you, that that's an entirely bad thing.

Latest is a group of stories that spin off from a paper published in October by pair of Russian physicists, who – in a display of serious, but also seriously speculative mathematics – theorize that the LHC's operation could in fact "lead to the formation of time machines (spacetime regions with closed timelike curves) which violate causality."

New Scientist offers a cover-story look at this idea, but if you really want to get a sense for how science reporting goes sensational, check out the British Sun's tabloid version:

Two scientists claim the Large Hadron Collider (LHC) - a giant atom-smashing machine - could open the door to unexpected visitors from the future.

The machine, due to come on stream this year, has been constructed at CERN, the European particle physics centre near Geneva.

And the scientists' calculations show it is possible the machine will tear a hole in the fabric of space and time, creating a gateway to tomorrow.

That means, with sufficiently advanced technology, people from the future might even be able to walk through it. ... The year 2008 might then become "Year Zero" for future time travelers, since it would only be possible to travel back as far as the first doorway in time.

Again with the caveats: I'm not nearly enough of a mathematician to critique the Russians' argument. But it's based on a series of very iffy ifs. It takes an idea from string theory and quantum gravity theories that tiny black holes could be created by the proton-proton collisions at the LHC.

That's generally viewed as extremely unlikely, even by many dedicated string theorists, at the energy levels reached by the LHC. But, OK, say all the features of the universe do line up in the right way, and the tiny black holes are not only possible, but within the LHC's reach. At this same black-hole energy level, wormholes could be created, the Russian scientists argue:

A wormhole forms a handle-like geometry, whose two mouths join different regions of spacetime. If the wormhole is traversed from mouth to mouth, it acts as a time machine allowing one to travel into the past or into the future.

In the best of the reporting on this idea, LHC-affiliated scientists are politely very, very skeptical."

News Source Wired

The Big Bang Wasn't the Beginning

Sun, 06 Jan 2008 19:41:57 GMT

What if the Big Bang wasn't the beginning of the universe, but only one stage in an endlessly repeated cycle of universal expansion and contraction?

So suggests mathematical physicist and string theorist Neil Turok. He thinks there may be many universes, at once interpolated but separate, like a mixture of gases. These universes are attracted to each other; every few trillions of trillions of years, they collide, explode, expand and contract, then repeat the sequence all over again.

I recently spoke with Turok, winner of the first TED Prize of 2008, for an upcoming Wired News Q&A. Here are some outtakes from our conversation:

On the Big Bang's problems:

The Big Bang theory rests very strongly on Einstein’s theory of general relativity, which combines with nuclear and particle physics and all the other physical laws to describe the contents of the universe. The theory is that 13.7 billion years ago, there was a singularity, a point of infinite density, and the universe emerged, emerging and very hot, from that singularity.

But the singularity is not describable with Einstein’s theory. The theory fails: everything goes to infinity. The density of the universe goes to infinity. The curvature of spacetime goes to infinity. All the properties we normally use to describe the universe and its contents just fail.

Experts just say, “Let’s assume the universe sprang into existence, start our decription a tiny fraction of a second after that, run the clock forward and never ask where it came from.”

The origins of Turok's motivations:

Well, a theory called inflation was invented to deal with the singularity: maybe the singularity was full of a weird type of energy that caused it to expand with exponential speed. My own work started because I was skeptical of this framework. It seemed to me that the inflationary models were adding so many ad-hoc ingredients to solve the problems. I like to have a simple solution, not some kind of Rube Goldberg machine.

Then string theory came along, and its successor, m-theory. It’s not fully understood yet, but it seems to anticipate some of the most profound features of the world. From the very simple assumption that all types of matter and all forces in the world can be described in terms of a string, a one-dimensional vibrating object, one is led to types of particles and forces like those we see: electromagnetism, quarks, neutrinos -- and you don’t get all those nasty infinities. And it has other remarkable features: according to string theory, the world doesn’t have three dimensions of space, but at least six more. All the laws of particle physics, all the properties we see, are fixed by the size and shape of these six extra dimensions.

Turok's theory:

Imagine two sheets on a washing line, and they're very close together, very nearly parallel. Those are two-dimensional sheets; ours are three-dimensional. Think of it as two intimately intertwined objects which are nevertheless able to exert force on each other, a pull. The Big Bang is the touching of those two sheets. When they touch, they release that energy.

Interestingly, Turok's theory hasn't always been well-received by Christians, for whom the Big Bang dovetails neatly with their creation myths. Conversely, New Age types have embraced this scientific picture of a cyclical universe without beginning or end. Turok, for his part, doesn't want any such attention. "I see religion and science as being two completely different things," he said. "Science studies how the world operates, not why it's here. I think the world is an incredible miracle, and we have to do whatever we can to appreciate it."

News Source

Scientists: Time Itself May Be Slowing Down

Sat, 29 Dec 2007 21:58:36 GMT

For a decade, scientists have puzzled over a surprising phenomenon: Supernovae stars viewed at extreme distances seem to be moving away from us faster than those nearby.

Most researchers have assumed that the stars have somehow accelerated – or that, more precisely, the rate of the expansion of the post-Big Bang universe itself has accelerated over time.

This was particularly odd given that the universe was thought to be dominated by matter, which should, through the aggregate gravitational effect of each bit pulling on the others, have led to a deaccelerating expansion, rather than the opposite. Thus, scientists have postulated an unknown kind of energy, now known as "dark energy," which would be responsible for the acceleration.

But hold on just a minute.

A group of scientists from the University of the Basque Country in Bilbao, and Spain's University of Salamanca have offered a different idea. Maybe it's the passage of time itself that's slowing down, they say. The distant galaxies only look like they're accelerating because our deep-space telescopes are essentially looking back in time to see them, to when time was going faster.

The theory, outlined in the New Scientist and the UK Telegraph, and in a paper published in Physical Review D, is based on a complex bit of string theory that remains entirely speculative today. Under this theory, our entire universe is embedded in a multidimensional "brane," which itself is floating through a higher dimensional space that we can't detect.

Naturally, the theory has a few chilling conclusions. If time is slowing, it could – in billions of years – actually come to a complete halt, University of the Basque Country professor José Senovilla told New Scientist.

Would that mean everything freezes in place forever? Apparently. Does forever mean anything if time itself has literally stopped? Pass...

In short, a brain twister. Of course, there's a catch, which Senovilla says his group hasn't yet considered. Another group of physicists has postulated that there may actually be two dimensions of time, rather than just one we all know and fear. Which would explain where all that lost time goes, I suppose.

News Source

Are Humans Evolving Faster?

Tue, 18 Dec 2007 21:38:58 GMT

Researchers have discovered genetic evidence that human evolution is speeding up -- and has not halted or proceeded at a constant rate, as had been thought -- indicating that humans on different continents are becoming increasingly different.

"We used a new genomic technology to show that humans are evolving rapidly, and that the pace of change has accelerated a lot in the last 40,000 years, especially since the end of the Ice Age roughly 10,000 years ago," says research team leader Henry Harpending, a distinguished professor of anthropology at the University of Utah.

Harpending says there are provocative implications from the study, published online Monday, Dec. 10 in the journal Proceedings of the National Academy of Sciences:

-- "We aren't the same as people even 1,000 or 2,000 years ago," he says, which may explain, for example, part of the difference between Viking invaders and their peaceful Swedish descendants. "The dogma has been these are cultural fluctuations, but almost any temperament trait you look at is under strong genetic influence."

-- "Human races are evolving away from each other," Harpending says. "Genes are evolving fast in Europe, Asia and Africa, but almost all of these are unique to their continent of origin. We are getting less alike, not merging into a single, mixed humanity." He says that is happening because humans dispersed from Africa to other regions 40,000 years ago, "and there has not been much flow of genes between the regions since then."

"Our study denies the widely held assumption or belief that modern humans [those who widely adopted advanced tools and art] appeared 40,000 years ago, have not changed since and that we are all pretty much the same. We show that humans are changing relatively rapidly on a scale of centuries to millennia, and that these changes are different in different continental groups."

The increase in human population from millions to billions in the last 10,000 years accelerated the rate of evolution because "we were in new environments to which we needed to adapt," Harpending adds. "And with a larger population, more mutations occurred."

Study co-author Gregory M. Cochran says: "History looks more and more like a science fiction novel in which mutants repeatedly arose and displaced normal humans -- sometimes quietly, by surviving starvation and disease better, sometimes as a conquering horde. And we are those mutants."

Harpending conducted the study with Cochran, a New Mexico physicist, self-taught evolutionary biologist and adjunct professor of anthropology at the University of Utah; anthropologist John Hawks, a former Utah postdoctoral researcher now at the University of Wisconsin, Madison; geneticist Eric Wang of Affymetrix, Inc. in Santa Clara, Calif.; and biochemist Robert Moyzis of the University of California, Irvine.

No Justification for Discrimination

The new study comes from two of the same University of Utah scientists -- Harpending and Cochran -- who created a stir in 2005 when they published a study arguing that above-average intelligence in Ashkenazi Jews -- those of northern European heritage -- resulted from natural selection in medieval Europe, where they were pressured into jobs as financiers, traders, managers and tax collectors. Those who were smarter succeeded, grew wealthy and had bigger families to pass on their genes. Yet that intelligence also is linked to genetic diseases such as Tay-Sachs and Gaucher in Jews.

That study and others dealing with genetic differences among humans -- whose DNA is more than 99 percent identical -- generated fears such research will undermine the principle of human equality and justify racism and discrimination. Other critics question the quality of the science and argue culture plays a bigger role than genetics.

Harpending says genetic differences among different human populations "cannot be used to justify discrimination. Rights in the Constitution aren't predicated on utter equality. People have rights and should have opportunities whatever their group."

Analyzing SNPs of Evolutionary Acceleration

The study looked for genetic evidence of natural selection -- the evolution of favorable gene mutations -- during the past 80,000 years by analyzing DNA from 270 individuals in the International HapMap Project, an effort to identify variations in human genes that cause disease and can serve as targets for new medicines.

The new study looked specifically at genetic variations called "single nucleotide polymorphisms," or SNPs (pronounced "snips") which are single-point mutations in chromosomes that are spreading through a significant proportion of the population.

Imagine walking along two chromosomes -- the same chromosome from two different people. Chromosomes are made of DNA, a twisting, ladder-like structure in which each rung is made of a "base pair" of amino acids, either G-C or A-T. Harpending says that about every 1,000 base pairs, there will be a difference between the two chromosomes. That is known as a SNP.

Data examined in the study included 3.9 million SNPs from the 270 people in four populations: Han Chinese, Japanese, Africa's Yoruba tribe and northern Europeans, represented largely by data from Utah Mormons, says Harpending.

Over time, chromosomes randomly break and recombine to create new versions or variants of the chromosome. "If a favorable mutation appears, then the number of copies of that chromosome will increase rapidly" in the population because people with the mutation are more likely to survive and reproduce, Harpending says.

"And if it increases rapidly, it becomes common in the population in a short time," he adds.

The researchers took advantage of that to determine if genes on chromosomes had evolved recently. Humans have 23 pairs of chromosomes, with each parent providing one copy of each of the 23. If the same chromosome from numerous people has a segment with an identical pattern of SNPs, that indicates that segment of the chromosome has not broken up and recombined recently.

That means a gene on that segment of chromosome must have evolved recently and fast; if it had evolved long ago, the chromosome would have broken and recombined.

Harpending and colleagues used a computer to scan the data for chromosome segments that had identical SNP patterns and thus had not broken and recombined, meaning they evolved recently. They also calculated how recently the genes evolved.

A key finding: 7 percent of human genes are undergoing rapid, recent evolution.

The researchers built a case that human evolution has accelerated by comparing genetic data with what the data should look like if human evolution had been constant:

The study found much more genetic diversity in the SNPs than would be expected if human evolution had remained constant.
If the rate at which new genes evolve in Africans was extrapolated back to 6 million years ago when humans and chimpanzees diverged, the genetic difference between modern chimps and humans would be 160 times greater than it really is. So the evolution rate of Africans represents a recent speedup in evolution.
If evolution had been fast and constant for a long time, there should be many recently evolved genes that have spread to everyone. Yet, the study revealed many genes still becoming more frequent in the population, indicating a recent evolutionary speedup.

Next, the researchers examined the history of human population size on each continent. They found that mutation patterns seen in the genome data were consistent with the hypothesis that evolution is faster in larger populations.

Evolutionary Change and Human History: Got Milk?

"Rapid population growth has been coupled with vast changes in cultures and ecology, creating new opportunities for adaptation," the study says. "The past 10,000 years have seen rapid skeletal and dental evolution in human populations, as well as the appearance of many new genetic responses to diet and disease."

The researchers note that human migrations into new Eurasian environments created selective pressures favoring less skin pigmentation (so more sunlight could be absorbed by skin to make vitamin D), adaptation to cold weather and dietary changes.

Because human population grew from several million at the end of the Ice Age to 6 billion now, more favored new genes have emerged and evolution has speeded up, both globally and among continental groups of people, Harpending says.

"We have to understand genetic change in order to understand history," he adds.

For example, in China and most of Africa, few people can digest fresh milk into adulthood. Yet in Sweden and Denmark, the gene that makes the milk-digesting enzyme lactase remains active, so "almost everyone can drink fresh milk," explaining why dairying is more common in Europe than in the Mediterranean and Africa, Harpending says.

He now is studying if the mutation that allowed lactose tolerance spurred some of history's great population expansions, including when speakers of Indo-European languages settled all the way from northwest India and central Asia through Persia and across Europe 4,000 to 5,000 years ago. He suspects milk drinking gave lactose-tolerant Indo-European speakers more energy, allowing them to conquer a large area.

But Harpending believes the speedup in human evolution "is a temporary state of affairs because of our new environments since the dispersal of modern humans 40,000 years ago and especially since the invention of agriculture 12,000 years ago. That changed our diet and changed our social systems. If you suddenly take hunter-gatherers and give them a diet of corn, they frequently get diabetes. We're still adapting to that. Several new genes we see spreading through the population are involved with helping us prosper with high-carbohydrate diet."

Adapted from materials provided by University of Utah.

News Source

New Discoveries of Northern Lights Energy Source

Tue, 18 Dec 2007 21:26:38 GMT

NASA's fleet of THEMIS spacecraft, launched less than 8 months ago, has made three important discoveries about spectacular eruptions of Northern Lights called "substorms" and the source of their power. The discoveries include giant magnetic ropes that connect Earth's upper atmosphere to the Sun and explosions in the outskirts of Earth's magnetic field.

"The mission is only beginning but THEMIS is already surprising us," says Vassilis Angelopoulos the mission's principal investigator at the University of California, Los Angeles.

The discoveries began in March less than a month after the five THEMIS satellites had been activated. "On March 23, 2007, a substorm erupted over Alaska and Canada producing vivid auroras for more than two hours." A network of ground cameras organized to support THEMIS photographed the display from below while the satellites measured particles and fields from above.

Right: Auroras over Alaska on March 23-24, 2007. Photo credit: Daryl Pederson. [More]

Right away the substorm surprised investigators: "The auroras surged westward twice as fast as anyone thought possible, crossing 15 degrees of longitude in less than one minute," says Angelopoulos. The storm had traversed an entire polar time zone in 60 seconds flat!

Also, "the display was surprisingly bursty." Photographs taken by ground cameras and NASA's Polar satellite (also supporting the THEMIS mission) revealed a series of staccato outbursts each lasting 10 minutes or so. "Some of the bursts died out while others reinforced each other and went on to become major events."

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Scientists have been tracking and studying substorms for more than a century, yet these phenomena remained mostly unknown until THEMIS went into action.

Even more impressive was the substorm's power. Angelopoulos estimates the total energy of the two-hour event at five hundred thousand billion (5 x 1014) Joules. That's approximately equivalent to the energy of a magnitude 5.5 earthquake.

Where does all that energy come from? THEMIS may have found an answer:

"The satellites have found evidence for magnetic ropes connecting Earth's upper atmosphere directly to the Sun," says Dave Sibeck, project scientist for the mission at the Goddard Space Flight Center. "We believe that solar wind particles flow in along these ropes, providing energy for geomagnetic storms and auroras."

A "magnetic rope" is a twisted bundle of magnetic fields organized much like the twisted hemp of a mariner's rope. Spacecraft have detected hints of these ropes before, but a single spacecraft is insufficient to map their 3D structure. THEMIS's five satellites were able to perform the feat.

Right: A magnetic map of a magnetospheric rope observed in cross-section by the THEMIS satellites on May 20, 2007. [Larger image]

"THEMIS encountered its first magnetic rope on May 20, 2007," says Sibeck. "It was very large, about as wide as Earth, and located approximately 40,000 miles above Earth's surface in a region called the magnetopause." The magnetopause is where the solar wind and Earth's magnetic field meet and push against one another like sumo wrestlers locked in combat. There, the rope formed and unraveled in just a few minutes, providing a brief but significant conduit for solar wind energy. Other ropes quickly followed: "They seem to occur all the time," says Sibeck.

THEMIS has also observed a number of relatively small explosions in Earth's magnetic bow shock. "The bow shock is like the bow wave in front of a boat," explains Sibeck. "It is where the solar wind first feels the effects of Earth's magnetic field." When a knot of magnetism within the solar wind hits the bow shock--"Bang!" he says. "We get an explosion."

The technical term for these explosions is "hot flow anomalies" or HFAs. HFAs boost the temperature of solar wind particles ten-fold (as high as 10 million degrees) and they can stop the solar wind dead its tracks. "This is no mean achievement considering the fact that the solar wind moves at supersonic speeds near a million miles per hour."

Above: A cartoon of a hot flow anomaly observed by THEMIS on July 4, 2007, and a computer simulation of the explosion. Credit: N. Omidi. [More]

"Hot flow anomalies may not play a major role in energizing auroral substorms--they happen too infrequently, less than once a day," notes Jonathan Eastwood of the University of California, Berkeley, who is studying them. "Nevertheless they are of interest. This is a fundamental physical process that accelerates particles to high energies and we are delighted to be able to study it."

Powerful substorms, giant magnetic ropes, explosions that stop the solar wind in its tracks: "We have much more to learn about all these things," says Angelopoulos. "I can't wait to see what comes next."

For more information about THEMIS, visit http://www.nasa.gov/themis/

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