Double Eruption, Coronal Mass Ejection - October 1st
On October 1st around 10:17 UT, widely-spaced sunspots 1302 and 1305 erupted in quick succession, revealing a long-distance entanglement which was not obvious before. NASA’s Solar Dynamics Observatory (SDO) recorded the double blast:
Since it was launched in 2010, SDO has observed many “entangled eruptions.” Active regions far apart but linked by magnetic fields can explode one after another, with disturbances spreading around the stellar surface domino-style. Yesterday’s eruption appears to be the latest example.
The part of the eruption centered on sunspot 1305 hurled a coronal mass ejection toward Earth. The relatively slow-moving (500 km/s) cloud is expected to reach our planet on Oct. 4th, possibly causing geomagnetic storms when it arrives. High-latitude sky watchers should be alert for auroras.
Dozens of giant craters spewing fresh water and brimming with bacteria have been found at the otherwise barren bottom of the Dead Sea, new research shows.
In 2010 the first diving expedition to the springs revealed “a fantastic hot spot for life” in the lake, which lies on the border of Israel and Jordan (see map), said team member Danny Ionescu, a marine microbiologist for the Max Planck Institute in Germany.
The team found several craters—each about 33 feet (10 meters) wide and 43 feet (13 meters) deep—at 100-foot (30-meter) depths on the lake’s bottom. The craters were covered with films and sometimes surprisingly thick mats of new bacterial species, Ionescu said.
These tiny communities live near thin plumes of fresh water that shoot from undersea springs, whose presence has long been suspected based on peculiar ripples on the Dead Sea’s surface.
To reach the springs, divers searched for abrupt drops along the sea floor while contending with very low visibility.
"When you put your head in [a crater] you cannot see anything—you have to have faith and will to explore," Ionescu said.
But once the water cleared near the base of the crater, seeing the plumes jetting from the earth was “a fascinating feeling,” he said.
Rivers and streams—most notably the Jordan River—once regularly infused fresh water into the Dead Sea.
The basin has no outlet, so water escapes only by evaporation. As fresh water evaporates, salty minerals dissolved in the water get left behind. Over time, this process made the Dead Sea much saltier than ocean water.
The lake’s saltiness means that larger organisms such as fish and frogs can’t survive in the Dead Sea. But a high concentration of magnesium also makes it surprising to find microbes in the lake.
"There are other hypersaline environments that are full of microbial life," Ionescu noted. "This, in my opinion, makes our discovery even more surprising."
In the 1950s countries in the Middle East, including Jordan and Israel, cut off the Jordan River’s supply to the Dead Sea to gain drinking water. The move severely lowered the lake’s water level—a loss that continues by up to a meter (four feet) a year, according to the research team.
Water in the lake, which already sits in the lowest place on Earth, has fallen by more than 80 feet (25 meters) in the past 40 years.
Few biologists have studied the water body in recent years, except following two major algae bloom events that colored the Dead Sea red in 1980 and 1992.
The surface blooms were caused by organisms different than those recently discovered at depth, Ionescu noted.
In general, the “study really changes how we see the Dead Sea, from a biological perspective,” said Kelly Bidle, an environmental microbiologist at Rider University in New Jersey who studies bacteria that live in salty habitats.
That’s because “seeing this diversity in a place we had never thought was there before” is very exciting, she said.
"Impressive" Craters Unique to Dead Sea
The 2010 expedition mapped an “impressive” network of about 30 craters, a landscape that has no parallel elsewhere on Earth, said team leader Ionescu, whose research is soon being submitted for publication.
Preliminary analyses of samples collected in the craters suggest that the springs’ bacterial communities are very diverse—akin to what you’d find living on rocks in a regular saltwater sea, he added.
The top of the springs’ rocks are covered with green biofilms, which use both sunlight and sulfide—naturally occurring chemicals from the springs—to survive. Exclusively sulfide-eating bacteria coat the bottoms of the rocks in a white biofilm. (See marine-microbe pictures.)
Not only have the organisms evolved in such a harsh environment, Ionescu speculates that the bacteria can somehow cope with sudden fluxes in fresh water and saltwater that naturally occur as water currents shift around the springs.
The existence of such adaptable bacteria is an “intriguing” idea that needs more research, Rider University’s Bidle said.
As of right now, “there is no such documented species that exists that could fit this bill”—all highly salt-adapted bacteria die when placed in fresh water, and vice versa, she noted.
If “your machinery is wired for high salt, it’s very difficult to imagine that you could go from an extreme amount of salt to near-freshwater biology.”
Even so, Bidle doesn’t totally rule out the idea: “When it comes to inhabiting extreme environments, nothing surprises me when it comes to microbial life,” she said.
Dead Sea Diving Not for Everyone
Ionescu and colleagues will visit the underwater craters again in October to study more about the behaviors and life cycles of the newfound bacteria.
It’s no easy task—each diver has to carry 90 pounds (40 kilograms) of weight to lower his or her buoyancy, since the sea’s high salt content tends to make people float.
Divers will also need to wear full face masks to protect their eyes and mouths. That’s because accidentally swallowing Dead Sea salt water would cause the larynx to inflate, resulting in immediate choking and suffocation.
Likewise, the intensely salty water would instantly burn and likely blind the eyes—both reasons why Dead Sea swimmers rarely fully submerge their bodies, Ionescu noted.
"It’s a very unique experience," Ionescu said of diving in the Dead Sea, but "I wouldn’t recommend it for recreational diving."
The Massive Vertical Structures Towering Above Saturn's Rings
This one is a 10 on the Galaxy wow meter: In images made possible only as Saturn nears equinox, NASA’s Cassini spacecraft has uncovered for the first time towering vertical structures in the planet’s otherwise flat rings that are attributable to the gravitational effects of a small nearby moon.
The search for material extending well above and below Saturn’s ring plane has been a major goal of the imaging team during Cassini’s “Equinox Mission,” the two-year period when the sun is seen directly overhead at noon at the planet’s equator. This novel illumination geometry, which occurs every half-Saturn-year, or about 15 Earth years, lowers the sun’s angle to the ring plane and causes out-of-plane structures to cast long shadows across the rings’ broad expanse, making them easy to detect.
Cassini’s cameras spotted not only the predictable shadows of some of Saturn’s moons, but also the shadows of newly revealed vertical structures in the rings themselves. And these observations have lent dramatic support to the analysis that demonstrates how small moons in very narrow gaps can have considerable and complex effects on the edges of their gaps, and that such moons can be smaller than previously believed.
(Reuters) - Unraveling one of the great enigmas of the visible universe, why it is made up largely of matter, will be the target of a ground-breaking research project kicked off on Wednesday at a meeting of leading physicists from eight countries.
More precisely, the program will aim to find why there is so little left of the anti-matter believed to have been present in equal quantities at the “Big Bang” 13.7 billion years ago but which then mysteriously disappeared, or all but.
The CERN particle physics research center said the program would be conducted with a new “Extra Low Energy Antiproton Ring,” dubbed ELENA, which will begin delivering large numbers of tiny anti-proton particles by 2016.
Attending this week’s meeting at CERN, which is leading the project to begin in 2013 with the ring’s installation, are scientists from Britain, Canada, Denmark, France, Germany, Japan, Sweden and the United States.
"This is a big step forward for anti-matter physics," said Walter Oelert, pioneer expert at CERN — home to the Large Hadron Collider (LHC) "Big Bang" machine — which said last week researchers had tracked particles traveling faster than light.
Anti-matter was discovered in 1932 after decades of theorizing, and was quickly absorbed into science fiction with its capacity to destroy any ordinary matter it touches.
The matter is converted into instant energy, a fact that has led to speculation that such reactions could fuel ultra-fast spacecraft for inter-stellar travel or be adapted for military use as a trigger for nuclear weapons.
Anti-matter — matter with negative gravity — has already been used in cancer treatments, some developed at CERN, but spokesman James Gillies said ELENA would focus on pure physics.
One of the prime questions facing researchers is why matter and anti-matter did not destroy each other at the time of the Big Bang, making creation of the universe and the emergence of life impossible, and why matter came out on top.
Gillies said ELENA was a low-cost project funded out of the 20-nation centre’s regular budget but would provide researchers with far more anti-protons than had been possible with earlier installations.
Project head Stephan Maury said ELENA, a small declerator ring to be housed alongside its existing but much less efficient anti-proton decelerator (AD), would deliver the anti-particles “at the lowest energies ever reached.”
From the AD, in operation since the early 1990s, the anti-protons must be slowed down by passing them through a series of foil filters, a process that leads to the loss of 99.9 percent before they reach the experiments.
The new ring through which they will travel will slow them down to under one 50th of the energy of the AD, trapping up to 50 percent of the particles or more.
Oelet said this would not only greatly enhance the research potential of current experiments at CERN but would also make it much easier to start a wider range of tests on the make-up and behavior of anti-matter.
Space Radiation Expected to Rise for Airline Passengers and Astronauts
by Charles Q. Choi, SPACE.com Contributor
Date: 27 September 2011
SUN Whips Out Massive Flare CREDIT: NASA
Radiation hazards are likely to increase for air travelers and spacefarers in coming years due to changes in solar activity, researchers say.
Cosmic rays from deep space and high-energy particles from the sun can be hazardous to astronauts and also can expose airline crews and passengers to radiation, as well as damage spacecraft, aircraft and satellites. Solar magnetic fields protect Earth by repelling incoming galactic cosmic rays, but the period of high solar magnetic activity known as the grand solar maximum that persisted throughout the Space Age now appears to be coming to an end, and solar particle levels might start rising at the same time.
Cosmic rays constantly bombard the Earth from deep space, but solar activity is dependent on the sun’s regular weather cycle. The sun is currently approaching the peak of its current 11-year cycle, called Solar Cycle 24. That peak will occur in 2013, NASA has said. [Stunning Photos of Solar Flares & Sun Storms]
When powerful sunstorms are aimed directly at Earth, they can pose a serious threat to astronauts in orbiting spacecraft, damage satellites, interfere with communications systems and impact power plants and other infrastructure on the surface. Mild space weather events — such as yesterday’s (Sept. 26) geomagnetic storm, sparked by a weekend solar flare — can also supercharge Earth’s northern lights displays.
Atoms can be transmuted from one element to another by the cosmic rays and solar particles that slam into them, events that scientists can detect in these ice samples. Researchers supplemented these ancient records with present-day data from a global network of neutron monitoring stations.
Based on these past records, the researchers predicted future variations in galactic cosmic ray levels, the near-Earth interplanetary magnetic field, sunspot number and large solar storms. They found the risk of hazardous space weather is likely to rise noticeably over the next century from the level in recent decades.
One should not necessarily put off air travel, said study co-author Michael Lockwood at the University of Reading in England.
"However, it is good to be aware that one is exposed to more hazardous particles, particularly on trans-polar flights," Lockwood told SPACE.com. "For really frequent, lifelong fliers, it might become wise to be like workers in the radiation industry and have more-frequent and more in-depth health checks. Also, to reduce exposure for passengers and crew to higher doses during solar events, flights may be diverted to lower latitudes and altitudes, with delay and cost implications — those extra costs will be reflected in ticket prices, of course."
The scientists detailed their findings online Aug. 19 in the journal Geophysical Research Letters.
That gigantic solar flare that lashed out toward Earth on Saturday is “the geomagnetic storm that just won’t go away,” the NOAA’s Space Weather Prediction Center (SWPC) in Boulder, Colo., said via its Facebook page today. And that appears to be true. Active Region 1302, pictured above, continues to pummel earth with solar energy and could disrupt satellite communications as it continues turning toward us in the days to come.
AR1302 unleashed a massive coronal mass ejection on Saturday that struck a glancing blow off Earth’s atmosphere yesterday, triggering brilliant auroras across the Northern Hemisphere. So far, the storm hasn’t caused any serious trouble here on the ground. Saturday’s solar explosion didn’t connect with a direct hit, and it is expected to do nothing more than continue to provide electrifying light shows to sky-gazers in Europe and Asia this evening.
But AR1302 is also not slowing down, and as the week wears on it will turn to face Earth more directly. An SWPC bulletin yesterday warned that for the next 3-5 days, we’re squarely in the solar storm’s sights. Another blast like Saturday’s and we may feel it here on Earth in the form of disrupted communications. A larger blast could do even more damage to the power grid and other infrastructure.
Just another thrilling week in the buildup to 2013’s solar maximum. See the sun as NOAA’s GOES-15 sees it today below.
Today’s Solar Activity, Captured by NOAA’s GOES-15: NOAA
This movie from the SOlar and Heliospheric Observatory (SOHO) shows the sun’s atmosphere – the corona – from September 17 to September 20. Numerous CMEs blasted off the sun during this period. Credit: ESA/NASA/SOHO › Play/Download video › Download still
The sun let loose with at least six coronal mass ejections (CMEs) — solar phenomena that can send solar particles into space and affect electronic systems in satellites — from 7 PM ET on September 18, 2011 until 1 PM on September 19. The ejections appear to come from points scattered over the surface of the sun. Two CME’s dissipated quickly, but four continue to spread outward from the sun. NASA models suggest that the leading edge of one CME will pass by Earth at around 5 PM ET on Sep 21, at which point sky watchers should be on the lookout for auroras.
Ever since the term “sexual fetish” was first used over a century ago, there’s been a raging scientific debate over what it means. Why does one person get off on shoes, while another gets off on certain large body parts? Are these erotic feelings signs of illness, or simply preferences that are as inexplicable and harmless as liking spaghetti more than sausage?
Though sexual fetishism started out as a fairly neutral term over a century ago in early psychiatry, it’s become one of the most contested ideas in medicine. Here’s why.
The term “sexual fetish” was first used in the late nineteenth and early twentieth centuries by psychiatrists like Magnus Hirschfeld to describe — in a neutral fashion — the many ways that people experience sexual desire. Specifically, Hirschfeld and his contemporaries defined fetishism as the act of eroticizing any non-living object or body part. It wasn’t a mental illness, but a description of a mental state. However, in a world where wanting even the most ordinary kinds of sex can be difficult and embarrassing, having a fetish could make people neurotic. As a result, psychiatrists like Richard von Krafft-Ebing, author of the influential 1886 book Psychopathia Sexualis, often associated sexual fetishism with mental illness.
Derangements of the Sexual Instinct
Most of the people writing about sexual fetishes before the 1930s were psychiatrists dealing with people who had come to them because they were uncomfortable with their lust for rubber aprons, bondage, fur, machines, and hundreds of other sexytime items that are listed exhaustively in books like Psychopathia Sexualis, Havelock Ellis’Studies in the Psychology of Sex, Wilhelm Stekel’s The Sexual Aberrations, and many early essays of Sigmund Freud. Each of these researchers took a slightly different view on sexual fetishism, though Freud is perhaps most famous for his idea neuroses arise when people desire any deviation from heterosexual sex where the penis goes into the vagina and stays there for a reasonable amount of time.
Given that many of their patients were no doubt neurotic, many doctors dealing with sexuality at that time were surprisingly supportive of a variety of sexual choices. Havelock Ellis, who wrote about homosexuality extensively, was in an open marriage with a lesbian and championed women’s right to choose their own sexual paths.
Hirschfeld, who deals with fetishes in his book Derangements of the Sexual Instinct, was perhaps the world’s first gay rights advocate. Through his Institute for Sexual Science in Berlin, he published a number of essays, and made public health films, about how homosexuality was a legitimate lifestyle and not a sickness. You can see excerpts from one of the movies he made, Different from the Others, here. The film depicts a romance between two men, and was made in 1919.
Even Wilhelm Stekel, credited with inventing the term paraphilia for “extreme” sexual fetishes, also noted in his work that there are many “normal” sexual fetishes — including bondage and domination — that are perfectly healthy and that are shared by many people without any detriment to society or themselves.
Though the Nazis destroyed Hirschfeld’s Sexual Sciences Institute, and burned most of the books and art in its collection, the work he had begun was continued in America by researchers like Alfred Kinsey. A zoologist who studied wasps, he turned to studying human sexuality in the 1940s and published two books — dubbed the “Kinsey reports” — which were summations of thousands of interviews he and his research team conducted with Americans about their sex lives. Though Kinsey never advanced any theories about whether fetishes were normal or not, the fact that he presented the whole range of sexual interests (from Missionary position and homosexuality, to piss fetishes and bestiality) from a detached, non-judgmental perspective was fairly remarkable.
Given that so many of the scientists describing sexual fetishes did not consider them to be pathological, how did the term “sexual fetish” come to be so strongly associated with sickness and perversion?
The Paraphilia Controversy
Stekel’s term “paraphilia” is still used in medicine today to diagnose any sexual activity that is “extreme” or deviates from the norm. The controversy here isn’t so much about whether people with fetishes feel bad about themselves — obviously, some people are comfortable with getting off on balloon porn, while other people are weirded out by it and seek help. Instead, the issue is that some fetishes are defined by the medical community as paraphilias, with all the stigmas such a diagnosis entails — including committing people with paraphilias to mental health facilities.
To understand why this is controversial, simply consider the strange history of paraphilias in theDiagnostic and Statistical Manual of Mental Disorders, or DSM, a compendium of mental illnesses used by the psychiatric community in the United States to classify people’s mental health. Sometimes, paraphilias are defined based on politics rather than objective research. For example, homosexuality was included in the DSM until 1974, as was “nymphomania,” or female promiscuity, until 1987. Both “diagnoses” were found to be a reflection of cultural biases, and were removed from the DSM after protests from doctors and civil rights groups.
The DSM may be merely pathologizing practices that many psychiatrists find distasteful. However, patients may find their sexual behavior neither distasteful nor a source of distress or dysfunction.
In other words, whether something is a paraphilia may be in the eye of the beholder — and therefore it isn’t a good category to include in a manual that’s used for medical diagnoses.
Psychiatrists like Ray Blanchard, who currently serves as chair of the DSM Paraphilias Sub-Work Group, argue that medical professionals need to retain the idea of paraphilias because there are some “paraphilic disorders that cause real anguish to the individual or predispose the individual to violate the rights of other people or harm them in serious ways.” The question is, what do you mean by “harm”? Does a consensual BDSM relationship count as a paraphilia if somebody gets a bruise?
Sometimes a Fetish is Just a Fetish
Today the scientific community remains divided on the questions of sexual fetishes and paraphilias. Some doctors, like Moser, believe that sexual fetishes are simply personal preferences — perhaps strange, but definitely harmless. Others want to lump a fetish for spanking or threesomes in with crimes like pedophilia or rape. As a result of expert testimony from such doctors, courts have removed children from the custody of parents who have a private interest in everything from bondage to polyamory. Whether your community defines your preferences as a harmless fetish or a harmful paraphilia can still alter the course of your life — and the lives of your family and friends, too.
In fact, some of us revel in trying to find (and cultivate) the most obscure possible fetishes just for our own lascivious amusement. For example, I’ve always loved mind control erotica. Why? Who knows, and who really cares? Tried to do it in real life a couple of times (consensually!), but that was a bit of a fail. Luckily, though, there are enough stories about mind control sex on the internet to fill the rest of my life with fetishistic glee. I’m sure you can think of a dozen other weirdly obscure fetishes off the top of your head, too.
What I’m trying to say is that there’s a very important corollary to Internet Rule 34, which states that if you can think of something, somebody has already made porn out of it online. And that corollary is: When you have a sexual fetish, you are never really alone.
7 Incredible NASA Corn Mazes: Cool Crop Circles for Science
by NANCY ATKINSON on SEPTEMBER 13, 2011
An amazing corn maze with a NASA theme, at Cornbelly’s in Lehi, Utah, one of seven around the US in 2011. Image courtesty of The MAiZE Inc.
Imagine looking out your airplane window (or alien spacecraft portal) and seeing a giant Mars Exploration Rover or an astronaut a half-kilometer long etched in …. a corn field? That’s exactly what is happening this fall, as seven farms across the US are participating in a special collaboration with NASA called Space Farm 7 to celebrate the space agency’s achievements and progress in space, as well as providing education and activities about agriculture. The farmers have created some absolutely amazing and intricate crop-circle-like formations that double as corn mazes, giving kids and families the chance to get lost — if you will — in space.
“You don’t always see an astronaut in a corn field,” said Adam Pugh from The Rock Ranchin Georgia, who approached NASA last year with the idea, “and there’s not an obvious connection between corn and NASA. But I thought it would be cool if we could work with NASA and highlight some of the NASA anniversaries going on and use our cornfield as an outdoor classroom to re-enthuse the new generation of youth about space exploration and get them fired up about looking towards the stars.”
Take a look at these awesome corn mazes, all unique and with a special NASA theme.
NASA-themed corn maze at Belvedere Plantation in Fredericksburg, Virginia. Image courtesy The MAiZE Inc.
“I’ve got kids that are nine-, four- and two- years old,” said Pugh, talking with Universe Today from the agri-tourism farm he operates, “and the only thing they know about astronauts is Buzz Lightyear. I felt it would be great if we could teach kids about the real astronauts and the real heroes that have done so much through space exploration to give us things we enjoy today like cell phones, solar panels and all the great things that space exploration has given to us.”
The farms that are part of Space Farm 7 create corn mazes every year, as part of their harvest-time autumn festivities, Pugh said, and this year seven farms have a space-themed maze. “Most of the places started as pumpkin patches or small farms and have all gotten into agri-tourism, an increasingly popular idea which uses an agricultural setting as a place for education or tourism. It’s all part of a growing trend of people buying local for their produce, meats and dairy products.”
Corn maze at Dell’Osso Farms in Lathrop, California. Image courtesty of The MAiZE Inc.
Pugh said farmers have noticed a disconnect between today’s youth and agriculture. “We have kids coming on our field trips who have no idea where milk or eggs come from – they just think they come from the store,” he said. “But real effort and skill goes into creating the food that we all enjoy. Our purpose is to not only entertain these folks and get them to spend quality time together and exercise but also educate them and help them realize where their food comes from.”
The SpaceFarm 7 celebration is very timely as this year NASA celebrates the 50th anniversary of the first American in space, the 30th anniversary of the first Space Shuttle mission and the 20th anniversary of the Hubble Space Telescope’s deployment in space. NASA has ten regional research centers located in the United States, and the individual Space Farms have each been paired up with their nearest space center in order to highlight that region’s contribution to NASA.
NASA-themed corn maze at Dewberry Farm in Brookshire, Texas. Image courtesty of The MAiZE Inc
Layla Dowdy from NASA’s Public Affairs Office said NASA is supporting this awesome outreach project with exhibits, and speakers, as well as an online national contest where winners earn a visit to Kennedy Space Center and the chance to dine with an astronaut. To enter, visit www.spacefarm7.com and vote on your favorite of the seven maze designs. A winner will be randomly selected at the end of October.
The celebrations at each of the farms will include a visiting astronaut or other NASA officials, as well as activities such as hobby-rocket launches, hands-on space education activities, and demonstrations from local astronomy clubs, in addition to the regular activities the agri-tourism farms have.
“We’re providing all sorts of neat opportunities for families to experience space exploration, in ways which are normally not accessible unless you travel to Houston or Kennedy Space Center,” Pugh said. “We’re bringing the education materials to people all over the US, and our shared objective with NASA is to reach 1 million kids.”
“We just want to encourage families to get outdoors and enjoy quality time together,” Pugh added. “Our whole purpose is to be good stewards of the land and share that with folks.”
Activities at The Rock Ranch include zip lines, paddle boats, pony rides and other fun outdoor activities where people can “enjoy nature and farmland,” Pugh said.
Corn maze at Liberty Ridge Farm in Schaghticoke, New York. Image courtesty of The MAiZE Inc
The mazes typically average 8 acres in size, said Kamille Combs from The MAiZE Inc, a company that helps farmers design and create their corn mazes.
Combs provided the opening dates for the 7 mazes across the US:
Are We Entering the 7th Stage of Evolution on Earth?
Milan Ćirković of the Astronomical Observatory of Belgrade, and one of the world’s leading authorities on astrobiology and the evolution of galaxies and baryonic dark matter, has outlined along with philosopher Robert Bradbury the six great mega-trajectories of the biological evolution on Earth:
1. From the origin of life to the ”Last Common Ancestor” 2. Prokaryote diversification 3. Unicellular eukaryote diversification 4. Multicellularity 5. Invasion of the land 6. Appearance of intelligence and technology.
The authors suggest a “postbiological” seventh mega-trajectory triggered by the emergence of artificial intelligence” at least equivalent to the biologically-evolved one. (Bradbury is the inventor of the matrioshka brain — a hypothetical megastructure, based on the Dyson sphere, of immense computational capacity).
In a fascinating discovery that counters a common theory that human evolution has slowed to a crawl or even stopped in modern humans, a recent study examining data from an international genomics project describes the past 40,000 years as a time of supercharged evolutionary change, driven by exponential population growth and cultural shifts.
The findings may lead to a very broad rethinking of human evolution, especially in the view that modern culture has essentially relaxed the need for physical genetic changes in humans to improve survival.
A team led by University of Wisconsin-Madison anthropologist John Hawks estimates that positive selection just in the past 5,000 years alone — dating back to the Stone Age — has occurred at a rate roughly 100 times higher than any other period of human evolution. Many of the new genetic adjustments are occurring around changes in the human diet brought on by the advent of agriculture, and resistance to epidemic diseases that became major killers after the growth of human civilizations.
"In evolutionary terms, cultures that grow slowly are at a disadvantage, but the massive growth of human populations has led to far more genetic mutations," says Hawks. "And every mutation that is advantageous to people has a chance of being selected and driven toward fixation. What we are catching is an exceptional time."
While the correlation between population size and natural selection is nothing new — it was a core premise of Charles Darwin, Hawks says — the ability to bring quantifiable evidence to the table is a new and exciting outgrowth of the Human Genome Project.
In the hunt for recent genetic variation in the genome map the project has cataloged the individual differences in DNA called single nucleotide polymorphisms (SNPs). The project has mapped roughly 4 million of the estimated 10 million SNPs in the human genome. Hawks’ research focuses on a phenomenon called linkage disequilibrium (LD). These are places on the genome where genetic variations are occurring more often than can be accounted for by chance, usually because these changes are affording some kind of selection advantage.
The researchers identify recent genetic change by finding long blocks of DNA base pairs that are connected. Because human DNA is constantly being reshuffled through recombination, a long, uninterrupted segment of LD is usually evidence of positive selection. Linkage disequilibrium decays quickly as recombination occurs across many generations, so finding these uninterrupted segments is strong evidence of recent adaptation, Hawks says.
Employing this test, the researchers found evidence of recent selection on approximately 1,800 genes, or 7 percent of all human genes.
This finding runs counter to conventional wisdom in many ways, Hawks says. For example, there’s a strong record of skeletal changes that clearly show people became physically smaller, and their brains and teeth are also smaller. This is generally seen as a sign of relaxed selection — that size and strength are no longer key to survival.
But other pathways for evolution have opened, Hawks says, and genetic changes are now being driven by major changes in human culture. One good example is lactase, the gene that helps people digest milk. This gene normally declines and stops activity about the time one becomes a teenager, Hawks says. But northern Europeans developed a variation of the gene that allowed them to drink milk their whole lives — a relatively new adaptation that is directly tied to the advance of domestic farming and use of milk as an agricultural product.
The biggest new pathway for selection relates to disease resistance, Hawks says. As people starting living in much larger groups and settling in one place roughly 10,000 years ago, epidemic diseases such as malaria, smallpox and cholera began to dramatically shift mortality patterns in people. Malaria is one of the clearest examples, Hawks says, given that there are now more than two dozen identified genetic adaptations that relate to malaria resistance, including an entirely new blood type known as the Duffy blood type.
Another recently discovered gene, CCR5, originated about 4,000 years ago and now exists in about 10 percent of the European population. It was discovered recently because it makes people resistant to HIV/AIDS. But its original value might have come from obstructing the pathway for smallpox.
"There are many things under selection that are making it harder for pathogens to kill us," Hawks says.
Population growth is making all of this change occur much faster, Hawks says, giving a tribute to Charles Darwin. When Darwin wrote in “Origin of the Species” about challenges in animal breeding, he always emphasized that herd size “is of the highest importance for success” because large populations have more genetic variation, Hawks says.
The parallel to humans is obvious: The human population has grown from a few million people 10,000 years ago to about 200 million people at A.D. 0, to 600 million people in the year 1700, to more than 6.5 billion today. Prior to these times, the population was so small for so long that positive selection occurred at a glacial pace, Hawks says.
"What’s really amazing about humans," Hawks continued, "that is not true with most other species, is that for a long time we were just a little ape species in one corner of Africa, and weren’t genetically sampling anything like the potential we have now."
The recent changes are especially striking.
"Five thousand years is such a small sliver of time — it’s 100 to 200 generations ago. That’s how long it’s been since some of these genes originated, and today they are in 30 or 40 percent of people because they’ve had such an advantage. It’s like ‘invasion of the body snatchers.’
The Daily Galaxy via University of Massachusetts Amherst and centauri-dreams.org
I stumble down the stairs and make my coffee. I settle in to my office chair, jump in a local chatroom to say goodmorning to my friends. When I log on, the chat room in uncharacteristically empty. One of the few online saw me come on and without even saying hello, asked if I had turned on a TV yet. I hadn’t, so I did.
There was no way I could have been prepared for what I saw. Moments after I tuned in and started digesting what was being reported, the 2nd plane hit. I immediately woke up my roommates and we watched events unfold for awhile. I had to go to work that day, so I showered in something of a daze. Got in my car and tuned in public radio for the ride to work. In transit, the first tower collapsed. Looking around me in traffic, I could see everyone else getting the same news. Faces of wonder, sadness, disbelief in every vehicle.. my own tears pushing at the back of my eyes.
I get to work and it’s unusually quiet for a normally fast paced environment. Radios are giving minute-by-minute reports of the chaos in New York. Shortly thereafter, the 2nd tower collapsed. Reports of the FAA grounding all air traffic comes in.
..and then it hits me.
My parents are on a trip in Europe, due to leave that day for home. My brother and sister in law are in Las Vegas on vacation. And two of my best friends are off camping in the wilds of Utah, oblivious to everything. I couldn’t concentrate on my work. I could barely think. Two days went by before I heard from my brother. He had spoken to my folks, who we’re stuck, at that time indefinitely, in London. But they were all safe. It was almost a week before I heard from my friends on the camping trip.
Facing so many unknowns and fears essentially on my own was something I took away from that day. Is my family dead? WIll I hear from my friends again? Am I or my other friends and family in imminent danger? Splitting my thoughts on 24 hour coverage of this mess and not knowing the fate of the people I care for, by the end of that day I was wreck. The country I’ve always known as unshakable, shook. But no matter how awful I felt, I had to keep reminding myself that people were suffering.
We were all hurting. We were all experiencing fears.
The world wept for us.. and for a time, we were united.
The rest you know as history, colored by your own experiences.
This skull belonged to Australopithecus sediba, a new hominin species recently discovered in South Africa. The two million year old fossils are some of the most complete ever discovered, and they could rewrite our evolutionary family tree.
As fossil finds go, the Australopithecus sediba find is a downright bonanza. Paleontologists first discovered the hominin at the Malapa site in 2008, and they’ve since found over 220 bones representing at least half a dozen individuals of all ages. Professor Lee Berger of Johannesburg’s University of the Witwatersrand explains the find:
"The fossils demonstrate a surprisingly advanced but small brain, a very evolved hand with a long thumb like a humans, a very modern pelvis, but a foot and ankle shape never seen in any hominin species that combines features of both apes and humans in one anatomical package. The many very advanced features found in the brain and body, and the earlier date make it possibly the best candidate ancestor for our genus, the genus Homo, more so than previous discoveries such as Homo habilis.”
Even better, these might just be the most accurately dated bones in the entire hominin fossil record. Analysis of the surrounding rocks indicate that they date back to a reversal of the Earth’s magnetic field, which we know occurred between precisely 1.977 and 1.98 million years ago. That means we can date these fossils to within just 3,000 years, which is practically unheard of for such an ancient find.
At just under two million years old, these specimens predate the emergence of Homo erectus by about 200,000 years, and it’s also about 100,000 years older than the oldest known Homo habilis fossil. It’s harder to establish concrete dates for when Homo habilis evolved versus Australopithecus sediba - both could have evolved anywhere between about 2.5 and 2 million years ago, and that’s a pretty massive span of time.
But it does appear that Australopithecus sediba played a pivotal role in the emergence of the later Homo genus. That would indicate that it either predates Homo habilis or that habilisdoesn’t actually belong in that genus after all, which some paleontologists such as Richard Leakey have long argued.
Before we continue, it might be good to quickly explain the differences between the Australopithecus and Homo genera. Basically, Australopithecus was significantly closer to the other apes than was Homo - it was much smaller, much less intelligent, was not strictly bipedal, and spent a lot of time in the trees.
Professor Berger also tackles this topic in explaining why sediba was categorized as part of Australopithecus:
The fossils have an overall body plan that is like that of other Australopiths – they have small brains, relatively small bodies and long and seemingly powerful arms. They do, however, have some features in the skull, hand and pelvis that are found in later definitive members of the genus Homo but not in other Australopiths. However, given the small brains and Australopith-like upper limbs, and features of the foot and ankle, the team has felt that keeping this species in the genus Australopithecus was the conservative thing to do. Nevertheless, sediba is turning out to be one of the most intriguing hominins yet discovered, and it certainly shows a mosaic of features shared by both earlier and later hominins.
A key reason for sediba's suddenly privileged position is its hands. Although they were probably primarily used for moving swiftly through the trees - a distinctly non-Homobehavior - the hands also appear capable of the precision grip, which means they were capable of making tools. We know that these particular fossils postdate the first recorded evidence of tools.
The sediba hands are the most complete in the fossil record until the time of the Neanderthals, more than a million years later, which allows for remarkably fine-grained analysis. It appears thatAustralopithecus sediba actually had a hand better adapted for tool-making than did Homo habilis, including the original 1.75 million year old find that defined Homo habilis - literally “handy man” - in the first place.
This doesn’t mean that Homo habilis wasn’t actually making tools - that 1.75 million year old hand was found near stone tools, which is partially why the species became so intrinsically associated with tool-making. But Australopithecus sediba does appear to represent a much stronger transitional stage between the tree-dwelling earlier Australopithecus species - including the famous Australopithecus afarensis specimen Lucy, who dates back 3 million years - and later tool-makers like Homo erectus.
So then, let’s say we remove Homo habilis from our direct ancestry - perhaps re-categorizing it as Australopithecus habilis, but that’s another argument for another decade - and slot in Australopithecus sediba as the direct ancestor of Homo erectus. What else can this new find tell us? One of the most intriguing finds has to do with brains and bipedalism.
The key here is the pelvis, which expanded in the Homo genus. There are two possible explanations for this - we need wider pelvises for stability while walking upright, or females need larger pelvises in order to give birth to children with larger brains and, thus, larger skulls. As Duke researcher Steven Churchill explains, Australopithecus sediba sheds some light on which of these was the real driving force of pelvic expansion:
"It’s clear there could be two things driving the evolution of the pelvis in our Homolineage. One is bipedal locomotion. Between six and two million years ago, we begin to see a lot of it. The other thing is our big brains. Our brains have to pass through the pelvis, so accommodations must be made. What’s cool about sediba is their pelvises are already different from other australopiths, and yet they’re still small-brained… It’s hard to imagine that there’s no change in locomotion behind all this.”
The small brains are themselves an intriguing point. While the brains do not fossilize, they do leave clear marks on the inside of the skull. From those indentations, the researchers can deduce a surprising amount about the brain. There’s evidence that the front of the brain was already starting to reorganize itself into something like the modern human frontal lobe, which is one of the keys to our current intelligence.
We wouldn’t have expected to find a frontal lobe like that in such an ancient species, and it suggests the hominin brain didn’t enlarge gradually from Australopithecus to Homo. Instead, this suggests that the later Australopiths began reorganizing their brains into something more akin to later Homo brains, and only then did the brains begin to radically increase in volume.
There’s a lot more still to come about this new find, and there’s high hope that the Malapa site will reveal still more ancient hominin specimens. Until then, let’s just welcome the newest member of our extended evolutionary family. We may have just discovered the evolutionary equivalent of our great-great-grandparent, and that’s pretty damn awesome.
If asked to imagine what prehistoric human sex was like, according to psychologist Christopher Ryan, most of us would conjure “the hackneyed image of the caveman, dragging a dazed woman by her hair with one hand, a club in the other…” Ryan says this image is mistaken in every detail. A much more likely picture of how it went down in prehistoric times was this: a caveman would quietly sit in the corner and watch another caveman have sex with a woman, patiently waiting his turn.
Apparently, prehistoric women were extraordinarily promiscuous, and like our primate ancestors, women are hard-wired to behave like chimps in the bedroom. In his book, Sex at Dawn: The Prehistoric Origin of Modern Sexuality, Ryan offers a biological explanation for why we find monogamy so difficult today. A male is interested in sex with one woman up until the point of orgasm, at which point he will immediately lose interest, fall asleep, or perhaps wonder off to find more action.
In other words, human males are in important ways sexually incompatible with human females, who are capable of multiple orgasms. So what is the evolutionary advantage of this? Take monogamy out of the equation, and the evolutionary logic becomes more evident. A woman can have multiple sexual partners. This may increase her chances of reproducing, and she needs to try it a lot to be successful. Compared to other animals, humans have an incredibly low rate of conception, based on the number of sexual acts we partake in. And so it is well that sex is so much fun for humans, because if that were not the case, we wouldn’t have made it this far.
So just what does it mean to make love like a caveman? It means have a lot of sex, partaking in, as Ryan describes it, the “seven million years of primate promiscuity” that our ancestors so heartily embraced as a species. That’s a lot of sex.
Watch Christopher Ryan explain the evolution of human sexuality here:
What’s the Significance?
According to Ryan, if we took an honest look at our dysfunctional sexual lives today, this is what we would find: we are all victims of a well-intentioned inquisition. American society has responded to this crisis by inventing a ‘marital-industrial complex’ of couples therapy, “pharmaceutical hard-ons,” sex advice columnists, and “creepy father-daughter purity cults.” Viagra breaks sales records every year. Pornography worldwide is a $100 billion business. Ryan says we spend all of this money to compensate for a fundamental disconnect we have with our nature.
For instance, why is monogamy so difficult? According to Ryan, we are biologically programmed against it. It was not until the advent of agriculture that man developed a notion of private property, and had reason to feel jealous of a promiscuous mate. Culture invented monogamy, and with it marriage, cheating, and a sense of shame that surrounds our sexual selves. Ryan is anything but a home-wrecker. His book offers no prescriptions for curing our disconnect with nature. What he does recommend, however, is that we lose this sense of shame we have when we feel or act certain ways that contradict our culture, but which are in perfect harmony with our sexual nature.
Jennifer Welsh, LiveScience Staff Writer Date: 04 September 2011 Time: 02:09 PM ET
Scripps Research scientists produce first stem cells from endangered species. Cells could make it possible to improve reproduction and genetic diversity for some species, possibly saving them from extinction, or to bolster the health of endangered animals in captivity. CREDIT: San Diego Zoo
Stem cells are quickly becoming an important tool for human medical treatments, and researchers are betting they will also be a useful tool for zoo animals. They are working to create stem cell lines from zoo animals, for use in treating animal diabetes and other ailments as well as helping the animals reproduce.
The scientists have already created a “frozen zoo,” which contains different types of cells from every animal there, and now they are putting together a “stem cell zoo.”
"There are only two animals in it," study researcher Inbar Friedrich Ben-Nun, of The Scripps Research Institute, said in a statement, "but we have the start of a new zoo, the stem cell zoo."
Stem cells are prized, because they can be turned into any type of cell in the body, a characteristic called pluripotency. The cells can even be turned into sperm or egg cells, and used in assisted reproduction to make more individuals of the species.
"The most important thing is to provide these stem cells as a resource for other people taking some of the next steps," said Jeanne Loring, also of The Scripps Research Institute.
Endangered stem cells
The researchers started with two species: the drill primate, a highly endangered primate genetically close to humans, and the northern white rhinoceros, which is genetically far from humans and also incredibly endangered.
To create the stem cells, the researchers used the same genes that are used to turn human cells pluripotent; they inserted those genes into the animals’ skin cells. They had originally tried to use genes from the animals themselves and their close relatives, but after more than a year of trying they were having little success.
The new technique isn’t very efficient yet, transforming just a few cells into stem cells at a time, but that’s enough, the researchers said.
Stem cell therapies
Both animals, the researchers said, were chosen because they could benefit from stem cells now. For instance, the drill primate suffers from diabetes when in captivity, and stem cell-based treatments for diabetes being researched in humans suggest the same may work in these primates.
The rhinoceros was chosen because it is one of the most highly endangered species on the planet, with only seven animals, all in captivity, in existence (two of which are in the San Diego Zoo Safari Park). They haven’t reproduced in several years, and because the population is so small there is a lack of genetic diversity, which could affect their survival.
If the researchers can use the stem cells to make sperm and eggs from skin cells of deceased animals in the frozen zoo, they could reintroduce some genetic diversity into the population, while also increasing its size.
"The best way to manage extinctions is to preserve species and their habitats," study researcher Oliver Ryder, of the San Diego Zoo, said in a statement. "But that’s not working all the time."
The rhinos are a perfect example, he said, because there are so few. “Stem cell technology provides some level of hope that they won’t have to become extinct even though they’ve been completely eliminated from their habitats.”
The study was published today (Sept. 4) in the journal Nature Methods.
Here’s a rare look at a rainbow over the skies of Ethiopia. Find out how this cloud — known as as “pileus cloud” — brightens the atmosphere.
Pileus clouds are formed over the towers of cumulus clouds. The cumulus clouds puff up through convection, or the upwards motion of moist air in one section. The moisture in the air condenses and forms the towers of the cloud. Above the cumulus clouds in the troposphere, ice crystals are compressed by the wall of upward-moving air. They form the little cumulus “caps” that are pileus clouds.
These clouds only form when the convective current is strong enough and the upper atmosphere has enough water in it to form the crystals. Even then, what most people see are puffs of white cloud over the top of the cumulus clouds, not dazzling rainbows.
As with any rainbow effect, the light has to be precisely placed. Light has to hit the cloud and diffract through the prism of the drops. But when light hits the cloud from behind, it usually hits the eye of the beholder head-on as well. This means that any rainbow effect is drowned in a flood of white light. Iridescent clouds are only visible when something blocks out the light from the sun while still showing the light through the clouds. In this case, the dark cumulus cloud blocks out the sunlight, while the pileus cloud shimmers.
In 2010, the Manhattan-sized Petermann glacier iceberg enters the Nares Strait: Credit: European Space Agency.
An ice shelf is poised to break off from a Greenland glacier and float out to sea as an island twice the size of Manhattan, scientists say.
"I don’t know exactly when," Jason Box, a climatologist with Ohio State Unversity’s Byrd Polar Research Center, told OurAmazingPlanet. "I wouldn’t be surprised if it happened today — or if it happened next summer."
Just a year ago, in August 2010, the same glacier produced an even larger iceberg — a mass of ice four times the size of Manhattan, the largest in recorded Greenland history — yet researchers warn that the next spectacular break could have more-dire consequences.
Box said it’s not clear when the 62-square-mile (160 square kilometers) ice shelf, which is dangling from Greenland’s Petermann Glacier, will detach from the mainland. “I think it’s more likely to occur during periods of melt, and that’s coming to an end, so I’m losing confidence it’s going to break this year,” Box said.
Ice shelves are enormous plates of ice that float on polar seas but are connected to the shoreline by the land-bound glaciers that feed into them.
During much of the Arctic melt season, summer sunlight pounds the Earth’s highest latitudes nearly 24 hours a day. Melting typically draws to a close in early to mid-September, when cooler temperatures and shorter days arrive.
Box said scientists first noticed a jagged crack in the glacier’s ice — a growing rift he dubbed ‘The Big Kahuna’ — in 2008. However, a subsequent search through satellite data revealed the rift first appeared about eight years earlier.
"We can see the crack widening in the past year through satellite pictures, so it seems imminent," Box said.
Ice shelf collapse can affect sea levels. Polar research has revealed that ice shelves act as giant floating doorstops for the glaciers that feed them; when ice shelves disappear, the glaciers that push against them speed up, reach the sea more quickly and thus melt faster.
Melting glaciers contribute to rising sea levels, which have wide-reaching effects around the world.
"Even though this is a far-off place, changes in the Arctic do influence the rest of us," Box said, pointing out that rising sea levels can magnify the effects of storm surges and flooding.
Satellite data indicate last year’s ice shelf break-off didn’t lead to significant glacier speed-up. But this ice shelf appears to be more firmly wedged against fjord walls, thereby serving as more of a restraint. “It seems a lot more likely that this next piece, when it goes, will produce a much larger speed increase,” Box said.
The portion of the Petermann Glacier that separated last year is still on the loose. Although greatly reduced in size, the floating chunk of ice remains some 4.3 miles (7 km) long as it lingers near the Labrador Coast. “It is enormous!” Box said, adding that colossal chunks of floating ice can be hazards to shipping traffic and oil rigs.
Closest Supernova in 25 Years Is a 'Cosmic Classic,' Astronomers Say
Date: 26 August 2011 Time: 10:23 AM ET
The arrow marks PTF 11kly in images taken on the Palomar 48-inch telescope over the nights of, from left to right, Aug. 22, 23 and 24. The supernova wasn’t there Aug. 22, was discovered Aug. 23, and brightened considerably by Aug. 24. CREDIT: Peter Nugent and the Palomar Transient Factory View full size image
Astronomers have spotted the closest supernova in a generation — and in a week or so, stargazers with a good pair of binoculars might be able to see it, too.
The supernova, or exploded star, flared up Tuesday night (Aug. 23) in the Pinwheel Galaxy, just 21 million light-years from Earth. It’s the closest star explosion of its type observed since 1986, and astronomers around the world are already scrambling to train their instruments on it.
Researchers said they think they caught the supernova, named PTF 11kly, within hours of its explosion.
"PTF 11kly is getting brighter by the minute. It’s already 20 times brighter than it was yesterday," Peter Nugent, of the Lawrence Berkeley National Laboratory and the University of California, Berkeley, said in a statement yesterday (Aug. 25).
"Observing PTF 11kly unfold should be a wild ride," added Nugent, who was the first person to spot the supernova. "It is an instant cosmic classic."
Peering at the Big Dipper
The supernova was discovered using the Palomar Transient Factory survey, which employs a robotic telescope at Palomar Observatory in Southern California. [Photos of Great Supernova Explosions]
The survey spotted PTF 11kly blazing up in the Big Dipper, otherwise known as the constellation Ursa Major. It is a Type Ia supernova. These explosions are thought to occur when a dying star called a white dwarf exceeds its weight limit (by accreting mass from a stellar companion, or merging with another white dwarf) and goes boom.
"Type Ia supernovae are the kind we use to measure the expansion of the universe," said Mark Sullivan of Oxford University, who was among the first scientists to follow up on the supernova detection. "Seeing one explode so close by allows us to study these events in unprecedented detail."
A rare skywatching treat
Researchers will be watching the supernova evolve over the next couple of weeks. Catching it so early in its formation and evolution is a rare treat, researchers said.
"We are finding new clues to solving the mystery of the origin of these supernovae that has perplexed us for 70 years," said Andrew Howell of UC Santa Barbara. "Despite looking at thousands of supernovae, I’ve never seen anything like this before."
This is the closest Type Ia supernova astronomers have observed since 1986, researchers said. And it’s getting brighter by the day. Soon, it may even be bright enough to see with binoculars.
"The best time to see this exploding star will be just after evening twilight in the Northern Hemisphere in a week or so," Sullivan said. "You’ll need dark skies and a good pair of binoculars, although a small telescope would be even better.”
This illustration shows the alien planet PSR J1719-1438, where ultra-high pressures caused carbon to crystallize in the remnant of a dead star, forming the extrasolar world. The resulting planet is made of diamond and orbits a dense pulsing star with a radius smaller than that of our sun. CREDIT: Swinburne Astronomy Productions View full size image
A newly discovered alien planet that formed from a dead star is a real diamond in the rough.
The super-high pressure of the planet, which orbits a rapidly pulsing neutron star, has likely caused the carbon within it to crystallize into an actual diamond, a new study suggests.
The planet’s parent star is a special kind of flashing star known as a millisecond pulsar, a rapidly rotating neutron star formed from a supernova. The entire system, which is only the second of its kind ever discovered, is located about 4,000 light-years from Earth in the constellation of Serpens (The Snake).
A gem of a find
Seventy percent of millisecond pulsars found have a companion, which provides additional energy to ramp up the pulsars’ rapid rotation. Generally, this companion is a dying star called a white dwarf; more than 180 millisecond pulsars have been found with white dwarfs over the years.
Theonly planet known to be orbiting in such a system was detected in 1992 — until now.”The pulsar was found in December 2009,” lead scientist Matthew Bailes of Swinburne University of Technology in Melbourne, Australia, told SPACE.com via email.”We’ve been on the trail of the companion ever since.” [The Strangest Alien Planets]
From the ashes of a supernova
Known as PSR J1719-1438, this particular pulsar completes more than 10,000 rotations in a minute. Tiny and compact, it’s only about 12 miles (20 kilometers) across, but it has a mass that is 1.4 times that of our sun.
PSR J1719-1438 transformed from an average star to a radio pulsar when a dying star in a binary system exploded. The compact core of the star formed with a very high rotation speed from the ashes of the supernova.
When the second star in the system reached the end of its life, it expanded as a red giant and finally morphed into a white dwarf. The pulsar began to suck mass off its companion, causing the pulsarto spin faster and faster until it attained its breakneck speed.
From dying star to diamond planet
What happened next depends on the system. Most white dwarfs continue to orbit the new millisecond pulsar, but some are consumed by it.
"The fate depends upon the mass of the white dwarf and how far it is from the pulsar," Bailes said.
If it is both close and massive, the two spiral together. Astronomers assume this is what happened to the 30 percent of millisecond pulsars found without a companion. [Top 10 Star Mysteries]
In the case of the diamond planet, astronomers think that the core of the white dwarf failed to merge completely with its companion.
"When they got very close, the star lost a lot of its matter and moved out to its safe distance of about a solar radius," Bailes said.
Now tiny, having lost more than 99.9 percent of its original mass and no longer engaged in the fusion reactions that drive a star, the dead core is classified as a planet.
Ironically, the star-turned-planet is larger than its sun. With a diameter of about 37,300 miles (60,000 km), it’s five times the size of Earth, but 3,000 times larger than the millisecond pulsar it orbits.
The planet itself orbits the pulsar in a little more than two hours. The entire system would fit within the diameter of our sun.
The research was published online in the Aug. 25 edition of the journal Science.
Remains in 3.4-billion-year-old rocks hint at when cellular life arose, and how it powered itself.
Researchers have found what could be the oldest microbial fossils yet documented. The traces, discovered in 3.4-billion-year-old Australian rocks, might help to resolve the question of when cellular life arose, and how it produced energy.
Martin Brasier, a palaeobiologist at the University of Oxford, UK, and his collaborators found the cell-like fossils in black sandstone of the Strelley Pool Formation in Western Australia, an ancient beach that is now inland. Their work is published in Nature Geoscience today1.
Chemical analysis of rocks hints that life was around as long ago as 3.5 billion years, but physical evidence of it is hard to come by, because it is difficult to prove that fossils that resemble cells are truly signs of life.
For example, structures thought to be fossilized cyanobacterial mats, found in the 1980s in the 3.5-billion-year-old Apex Chert Formation, 30 kilometres from Strelley Pool, were this year shown to have an inorganic origin (see Filamentous figments in the Apex Cherts). Such uncertainty has made the question of when life arose hugely controversial.
Brasier had been critical of the Apex Chert fossils, but the latest findings should cheer researchers in the field, he says. “This goes some way to resolving the controversy over the existence of life forms very early in Earth’s history. The exciting thing is that it makes one optimistic about looking at early life once again.”
Signs of life
The fossils’ sizes, shapes and carbon-containing cell walls are characteristic of bacterial colonies. The traces range between 5 and 80 micrometres in diameter, and take the shapes of spheres, ellipsoids and rods.
The cell walls are of uniform thickness, unlike the highly variable carbonaceous layers found in inorganic traces formed by geological processes. The fossils are also depleted in carbon-13 — the heavier form of carbon found in the atmosphere. This is a sign of biological activity, because living organisms preferentially use the lighter form, carbon-12, in their biological processes.
"The authors have demonstrated as robustly as possible, given current techniques and the type of preservation, the biological origin of these microstructures," says Emmanuelle Javaux, a palaeobiologist at the University of Liège in Belgium. However, she remains cautious, adding: "Maybe one day we will come up with a non-biological explanation for this type of microstructure — only time will tell."
Micrometre-sized crystals of iron sulphide — pyrite, or fool’s gold — were found in and around the fossils’ cell walls. This pattern of pyrite deposition also occurs in modern bacteria that power their metabolism by reducing sulphur-containing particles called sulphates to sulphides, although it is not conclusive evidence that the fossil cells also produced energy in this way.
The possibility of linking a microfossil to its metabolism is the most exciting aspect of the work, says Javaux. “This could be a new way to identify microfossils,” she says.
Image Caption: The fossils’ size, shape and chemical composition suggests that they are the remains of microbial life.D. Wacey/UWA
Check. This. Out: a perfectly-formed collapse pit on Mars that leads to an underground cavern!
This was taken by the Mars Reconnaissance Orbiter in July 2011. See the hole in the bottom? You can tell from the lighting that this is an underground opening to a cavern — a skylight. Quite a few of these have been found on Mars, actually. We see them on Earth and even on the Moon. Given the angle of the shadows, the vertical distance from the bottom of the pit to the floor of the cavern is about 20 meters (65 feet). Watch your step!
Here’s how we think skylights like this form. In the distant past, Mars was geologically active. Rivers of lava ran across the surface. If the surface of the lava hardens it can form a roof, allowing the lava underneath to continue flowing; these are called lava tubes and there are bazillions of them in Hawaii, for example. Eventually, the source of the lava chokes off and the lava flows away, leaving the empty tube underground. If the roof is thin in one spot it can collapse. Sometimes that just leaves a hole, but apparently in this case it was under a sand field. Some of the sand must have fallen into the chamber below and eventually blown away, leaving the pit and the hole. The pit is located not too far from Pavonis Mons, a known (long-dead) Martian volcano.
The hole is about 35 meters (115 feet) across, so the pit is about 175 meters (nearly 600 feet) across the rim. I love how it sits in an otherwise nearly featureless sand field; the contrast is beautiful. In the high-res image you can see boulders perched on the pit wall, having rolled part of the way down as well. The inside of the pit has lines and furrows that are instantly recognizable to anyone who has tried to dig a hole at the beach and had sand continually flow down from the rim.
It would be incredible to see something like this up close. It’s possible eventually someone will: such lava tubes would make good homes for future Mars explorers; they’d be protected from sand storms, temperature swings, and solar radiation (which is worse than for us on Earth because Mars doesn’t have a strong magnetic field to protect it).
Image credit: NASA/JPL/University of Arizona. via reddit.
Sunspot-Spotting Method May Improve Solar Storm Warnings
by Denise Chow, SPACE.com Staff Writer
Date: 18 August 2011
A photo of a sunspot taken in May 2010, with Earth shown to scale. The image has been colorized for aesthetic reasons. This image with 0.1 arcsecond resolution from the Swedish 1-m Solar Telescope represents the limit of what is currently possible in terms of spatial resolution.CREDIT: The Royal Swedish Academy of Sciences, V.M.J. Henriques (sunspot), NASA Apollo 17 (Earth)
Scientists have found a way to spot active regions of the sun, below the solar surface, a full day or two before they erupt as sunspots on our nearest star, researchers said.
Sunspots, which are temporary dark splotches on the sunwith strong and concentrated magnetic fields, remain largely a mystery, but a team of astronomers has developed a new technique to detect these dynamic regions deep within the sun before they become visible on the surface. This new method, which measures acoustic waves beneath the sun’s surface, could help scientists create better and more accurate ways to forecast space weather and potentially dangerous solar storms.
"It’s the first time that we could detect sunspots before they appear at the surface — this is something that we could not do before," Stathis Ilonidis, a Ph.D. student at Stanford University in Palo Alto, Calif., and lead author of the study, told SPACE.com. "It’s very important to monitor solar activity and predict severe space weather events and we believe this work will be important for space weather forecasts." [Photos: Sunspots on Earth’s Closest Star]
The sun’s spots and magnetic field
Sunspots are patches on the surface of the sun that can be as large as Earth. The origin of these structures is unknown, but they are caused by intense magnetic activity and sometimes erupt into energetic solar storms that blast streams of charged particles into space.
Powerful solar storms can occasionally wreak havoc on Earth’s magnetic field by knocking out power grids, disrupting satellites, or posing hazards to astronauts in space. Astronomers keep a close eye on sunspots because their number and frequency act as indicators of the sun’s activity, which fluctuates on a roughly 11-year cycle.
Typically, the sun takes about 5.5 years to ramp up from a solar minimum, when there are few sunspots, to a solar maximum, when sunspot activity is amplified. [Worst Solar Storms in History]
Previously, sunspot regions could only be observed after they appeared on the surface, the researchers said, and little is known about the complex processes in the solar interior that give rise to the dark features.
Ilonidis and his colleagues examined sound waves and vibrations generated by the turbulent movement of plasma inside the sun. This technique, called helioseismology, is similar to how scientists study seismic events like earthquakes on Earth.
Acoustic travel-time perturbations detected at a depth of about 37,300 miles (60,000 km) on the left, and simultaneous observations of the photospheric intensity (middle) and magnetic field (right). The images of the upper row were taken at about 11:30 p.m. EDT (0330 GMT) on October 26, 2003 and those of the lower row about two days later. CREDIT: SOHO/MDI Team
Listening to the sunThe astronomers zeroed in on specific regions of the sun and selected pairs of reference points on the solar surface to measure the time it takes for sound waves to travel between the two locations from a depth of about 37,300 miles (60,000 kilometers).
"These waves travel along a path inside the solar interior," said Junwei Zhao, one of the study’s co-authors. "Travel times get perturbed if there are magnetic fields located along the wave’s travel path."
Using this time-distance seismology, the researchers found that when acoustic waves crossed a sunspot, they propagated faster, making the travel times shorter. For a large sunspot, the discrepancy was between 12 to 16 seconds, Ilonidis said.
"We made a travel-time map that showed which locations inside the sun had longer and shorter travel times," Ilonidis said. "We identified locations where the travel time was significantly shorter, and from that, we could see that this location is a sunspot region."
After the astronomers identified these active areas, large emerging sunspot regions became visible on the solar surface one day later, and smaller sunspot regions appeared two days later.
The study’s findings are published in the Aug. 19 issue of the journal Science.
The sun’s ebb and flow
In the study, Ilonidis and his colleagues successfully detected four sunspot regions. In order to test the significance of their results, the astronomers also analyzed nine regions where they did not find strong acoustic signals, and which later showed no sunspots.
The astronomers confirmed their findings using past and recent data from NASA’s Solar Dynamics Observatory (SDO) and the Solar and Heliospheric Observatory (SOHO), a joint mission of NASA and the European Space Agency.
To build upon their research, and to collect more data, the researchers intend to analyze more active and quiet regions of the sun to hone the accuracy of the time-distance seismology technique. The astronomers are also hoping to probe greater depths of the solar interior, which could also improve the amount of warning time before these active regions erupt.
"At 60,000 km, we observe the sunspot regions one to two days later at the surface," Ilonidis said. "If we need predictions of more than two days in advance, we need to go deeper."
Image courtesy Eric Rignot, NASA Jet Propulsion Laboratory and University of California Irvine
The first complete map of the speed and direction of ice flow in Antarctica will help scientists to track future sea-level increases, according to the team behind the project.
NASA-funded researchers this week revealed the map, which shows glaciers flowing thousands of miles from the continent’s deep interior to its coast. The team created the map using integrated radar observations from a consortium of international satellites.
According to Eric Rignot of NASA’s Jet Propulsion Laboratory: “This is like seeing a map of all the oceans’ currents for the first time. It’s a game changer for glaciology. We are seeing amazing flows from the heart of the continent that had never been described before.”
A paper about the ice flow, along with the map, was published online Thursday in Science Express.
Rignot and University of California Irvine scientists Jeremie Mouginot and Bernd Scheuchl used billions of data points captured by European, Japanese and Canadian satellites to weed out cloud cover, solar glare and land features masking the glaciers. With the aid of NASA technology, the team painstakingly pieced together the shape and velocity of glacial formations, including the previously uncharted East Antarctica, which comprises 77 percent of the continent.
Like viewing a completed jigsaw puzzle, the scientists were surprised when they stood back and took in the full picture. They discovered a new ridge splitting the 5.4 million-square-mile landmass from east to west.
The team also found unnamed formations moving up to 800 feet annually across immense plains sloping toward the Antarctic Ocean and in a different manner than past models of ice migration.
“The map points out something fundamentally new: that ice moves by slipping along the ground it rests on,” said Thomas Wagner, NASA’s cryospheric program scientist in Washington. “That’s critical knowledge for predicting future sea level rise. It means that if we lose ice at the coasts from the warming ocean, we open the tap to massive amounts of ice in the interior.”
The below animation (VIEW on YouTube) shows the motion of ice in Antarctica as measured by satellite data from the Canadian Space Agency, the Japanese Space Agency and the European Space Agency, and processed by NASA-funded research from the University of California, Irvine. The background image from the Landsat satellite is progressively replaced by a map of ice velocity, which is color-coded on a logarithmic scale.
Tiring of the annual two-week break in a Med hot spot? Fed up with overcrowded resorts with no room to move?
Then how about a real get-away-from-it-all holiday with plenty of space – in space?
Russia yesterday announced plans for a hotel in orbit 217 miles up which would house seven guests in four cabins and have huge windows for views of the Earth turning below.
Futuristic: Orbital Technologies has revealed plans for a space hotel, which could be open by 2016
Just getting there will be an adventure in itself – it will take two days aboard a Soyuz rocket – and it won’t exactly be a budget holiday: A five-day stay will cost you £100,000, on top of £500,000 for your journey.
The hotel, or the Commercial Space Station to give it its proper name, is due to open by 2016 and, according to those behind it, will be ‘far more comfortable’ than the International Space Station used by astronauts and cosmonauts.
In the weightlessness of space, visitors can choose to have beds that are either vertical or horizontal, while showers will be sealed affairs to stop water going where it shouldn’t (those aboard the International Space Station must make do with sponge baths until they return home).
Tourists, who will be accompanied by experienced crew, will dine on food prepared on Earth and sent up on the rocket, to be reheated in microwave ovens.
The plan is to do away with the freeze-dried tubes of nourishment given to astronauts and replace them with delicacies such as braised veal cheeks with wild mushrooms, white bean puree, potato soup and plum compote.
Space tourism: The hotel room pods will be fitted with binoculars and cameras so guests can enjoy the spectacular intergalactic views
Space age: The rooms will also act as an emergency bothole for astronauts at the manned space station
Iced tea, mineral water and fruit juices will be available, but alcohol will be strictly prohibited. Toilets will use flowing air instead of water to move waste through the system.
Waste water will be recycled, while the air will be filtered to remove odour and bacteria and then returned to the cabin.
Sergei Kostenko, chief executive of Orbital Technologies which will construct the hotel, said: ‘Our planned module inside will not remind you of the International Space Station. A hotel should be comfortable inside, and it will be possible to look at the Earth through large portholes.
‘The hotel will be aimed at wealthy individuals and people working for private companies who want to do research in space.’
Tourists might also find themselves playing host to unexpected guests – there is a plan for the hotel to be used as an emergency bolthole for astronauts aboard the International Space Station if there is a crisis, rather than bringing them all the way back to Earth.
Drop-off point: Guests will be sent in to the Commercial Space Station via Russian Soyuz rockets
Exclusive: The hotel will be aimed at wealthy individuals and people working for private companies who want to do research in space
Opening time: Orbital Technologies said it hoped the hotel will be up and running in just five years time
Price: The amount spent on the project has not been revealed, but a five-day stay will cost around £100,000
The scope of the problem is enormous; more than 17,000 objects of a size greater than 10cm reside in low-Earth orbit. But the greater problem on the horizon is that each of the largest of these represents the potential to create thousands more.
"In our opinion the problem is very challenging and it’s quite urgent as well," said Marco Castronuovo, the Italian Space Agency researcher who authored the paper.
"The time to act is now; as we go farther in time we will need to remove more and more fragments," he told BBC News.
In 2007, China demonstrated an anti-satellite system, destroying one of its own defunct satellites and creating 2,000 extra bits of debris in the process. More recently, a collision between US and Russian satellites created even more.
What is feared is a kind of chain reaction, called the Kessler syndrome after the Nasa scientist who first described it in 1978, in which fragments hit other fragments which in turn hit more, creating a cloud of debris that will make vast swathes of low-Earth orbit completely unusable.
The debris presents a risk not only to other man-made satellites in orbit, but occasionally also to the International Space Station and manned space missions.
Low-Earth orbit is an increasingly crowded space
The new research identifies more than 60 objects at a height of about 850km, and two thirds of those weigh more than three tonnes each - many moving near a speed of 7.5km/s. Most of these largest threats are spent rocket bodies, and it is there that Dr Castronuovo thinks the effort should begin.
"It’s difficult from a political point of view; many of these objects belong to nations that are not willing to co-operate or do not allow access to their objects even if they are at the end of their operative life, and there is no international regulation on who should remove the objects that are left in space," he said.
"If we start concentrating on the spent rocket bodies - which do not have sensitive equipment on board -it should not pose any problem to the owner to give permission to remove them; and there’s no doubt they are not operative anymore."
Dr Castronuovo proposes a scheme in which small satellites are deployed on seven-year missions, each with two robotic arms: one to intercept a rocket body or failed satellite and hang on, and another to affix an ion-engine thruster that will drive the debris out of orbit.
The satellites would then release the debris, hopping from one to the next in a choreographed dance with five to ten large objects per year.
"The proximity operations and maneuvering talked about here is not easy, but the technology is getting there for that; the idea that you go and attach yourself to something in orbit is becoming more credible," said Stuart Eves, principal engineer for Surrey Satellite Technology.
"People have come up with all sorts of daft ideas… that are really science fiction at the moment. Something like this is a lot more practical."
Nevertheless, the greater problem may be political, as any proposal struggles to be seen as a purely aimed at space junk, Dr Castronuovo said.
"This kind of approach could be seen as a threat to operative systems; if you have the power to go to an object in space and pull it down, nothing prevents you from going to an operative satellite and pulling it down, so it’s really a delicate matter."
Computer Chip-Sized Spacecraft Will Explore Space In Swarms
by Peter Murray August 15th, 2011
We knew to expect a paradigm shift with the end of the space shuttle program, but this is ridiculous. Mason Peck and his group of forward-thinking engineers are taking NASA’s slogan of Faster, Better, Cheaper to the extreme. Their spacecraft will cut down travel time to Alpha Centauri from thousands of years to just a few hundred, and instead of the $1.7 billion it takes to build a space shuttle, Peck’s ships can be built for an amazing $33.
I might mention that there’s no room for astronauts. In fact, if one were to try and board these spacecraft they would crush it.
Okay, maybe Peck’s Sprites, as they’re called, aren’t going to be the next manned space vehicle, but they could be the first of a new breed of satellites that are so cheap and innovative – they don’t need fuel – they could be an important addition to our satellite-based efforts to study the universe.
In stark contrast to the present approach of sending satellites costing tens or hundreds of millions of dollars for single missions, Peck’s team at Cornell’s School of Mechanical and Aerospace Engineering envision a swarm of wafer-sized spacecraft that sense their surroundings together and send data back to the earth in aggregate.
The spacecraft are called Sprites and they weigh about 10 grams each. Integrated circuits 3.8 cm on a side, they’re literally spacefaring computer chips. This past May the space shuttle Endeavour brought three Sprite prototypes to the International Space Station. Fixed to the station’s exterior, they are currently in the early days of a two year test to see how they stand up to the harsh elements of space.
Compared to your typical satellite the faculties of a single miniscule Sprite are severely limited. The Sprites at the station right now are equipped with seven tiny solar cells, a microprocessor with a built-in radio, an antenna, an amplifier, and special circuitry that activates the microprocessor when the solar cells have stored up enough energy to emit a single radio-frequency “beep.” The beeps not only tell operators on Earth that the Sprites are still functional, they’re data that can be used to estimate the angle of sunlight hitting the chip as an oblique angle will take longer to charge the solar cells than direct light that hits at a right angle. Not the most revolutionary sort of space exploration, it’s a proof-of-principle that will show the Sprites can sense their surroundings as a population of individual sensors – albeit a population of three. When they do it will be first tiny steps towards a new paradigm of distributed space exploration.
NASA astronaut Andrew Feustel, STS-134 mission specialist, installs and photographs the experimental module that includes three Sprites.
The Sprites of the future will do more. As Peck describes in an IEEE article, semiconductors will fit the solar cells, energy-storing capacitors, and “all the memory and processing capability you could want” onto a single chip. These will support experimental payloads such as spectrometers that break down the light emitted by stars and planets, for example, and use it to determine the chemicals that make up those stars and planets. A chip equipped with load sensors would be able to measure impacts made by space particles. Chemical sensors and simple CMOS cameras – essentially your common digital camera – can also be added. With these sorts of eyes and ears, tens of thousands of Sprites could explore space in ways impossible with conventional satellites. Peck describes a scenario in which Sprites in orbit between the Earth and the sun would send a signal when the local magnetic field or the number of charged particles that hit the spacecraft exceed some preset value. Each Sprite will be a single detector and provide just one data point. “But a network of these scattered chips could produce 3-D snapshots of space weather, something no traditional spacecraft, no matter how sophisticated, could ever do on its own.”
But don’t expect the Sprite swarm to be anything like the self-organizing nanobots of Michael Crichton’s Prey that were able to take a car ride in the shape of a human. Sprites simply won’t have the power for realtime communication – each will be acting on its own. Sprite swarms should be achievable, however, by harnessing the grouping power of space’s gravitational eddies and currents. The Interplanetary Transport Network is the vast array of virtual highways that arise from the gravitational pull of the planets and other celestial bodies. In the same way the interplanetary satellites of old were flung around Jupiter and Saturn in a gravity assist slingshot, a much smaller spacecraft could be ferried between planets along the much weaker gravitational forces that exist between planets. Another propulsion source is provided by the light given off by the sun. Photons that are continually expelled by the sun carry momentum. Just as they strike dust particles at the speed of light and blow them out of the solar system, photons could strike the dust-like Sprites and push them to the orbits of Jupiter or Saturn and beyond. Yet another way to steer the Sprites is to use a planet’s magnetic field. A charged particle that is moving will feel the tug of a magnetic field. A Sprite isn’t normally charged, but it could give itself a well-timed electrical charge to change its course of direction. If it found itself in the presence of a very large magnetic field, such as Jupiter’s which is 20,000 times as strong as Earth’s, it could literally follow in the paths of the Voyager and Pioneer satellites and get a particle accelerator-type planetary assist rather than a gravity assist.
If you picture a Sprite right now as something akin to a powerless piece of dust being capriciously pushed and pulled by the wind then you’re thinking along the lines of Peck and his team. “The idea goes back at least 15 years, and it has its origins in “smart dust” – tiny microelectromechanical sensor systems that can be used to measure light and temperature, register movement and location, and detect chemical and biological substances.” He and his graduate student, Justin Atchison, set out to see if they could explore space in new ways, and do it way cheaper. Space shuttle payloads costed about $10,000 per pound to fly. And putting a satellite in orbit costs between $50 and $400 million. At 10 grams each, 10,000 Sprites would weigh 100 kg – negligible as far as space payloads go. And Peck wants to get them down between 5 and 50 milligrams so that photons and magnetic fields could propel them that much faster.
If he succeeds in miniaturizing them further, Sprites may just be our ticket to the stars. At such small sizes the Sprites could travel at speeds fast enough to reach our nearest star, Alpha Centauri, in a few hundred years. That may not sound very fast, but our next best option at the moment – solar sails – would take at least a thousand years to get us there, more than likely longer.
The Sprites represent a paradigm shift in space exploration. Their materialization was made possible by advances in integrated circuit and superconductivity technologies. As these technologies advance further and are manufactured on the nanometer scale, spacecraft like Sprites will become faster and more powerful. It’s hard to say right now what their role in space exploration will be in the coming decades, but one can only expect that role to be as unorthodox as the Sprites themselves.
Researchers at MIT’s Lincoln Lab have developed technology that may someday cure the common cold, influenza and other ailments.
Most bacterial infections can be treated with antibiotics such as penicillin, discovered decades ago. However, such drugs are useless against viral infections, including influenza, the common cold, and deadly hemorrhagic fevers such as Ebola.
Now, in a development that could transform how viral infections are treated, a team of researchers at MIT’s Lincoln Laboratory has designed a drug that can identify cells that have been infected by any type of virus, then kill those cells to terminate the infection.
The microscope images above show that DRACO successfully treats viral infections. In the left set of four photos, rhinovirus (the common cold virus) kills untreated human cells (lower left), whereas DRACO has no toxicity in uninfected cells (upper right) and cures an infected cell population (lower right). Similarly, in the right set of four photos, dengue hemorrhagic fever virus kills untreated monkey cells (lower left), whereas DRACO has no toxicity in uninfected cells (upper right) and cures an infected cell population (lower right). | Enlarge image
In a paper published July 27 in the journal PLoS One, the researchers tested their drug against 15 viruses, and found it was effective against all of them — including rhinoviruses that cause the common cold, H1N1 influenza, a stomach virus, a polio virus, dengue fever and several other types of hemorrhagic fever.
The drug works by targeting a type of RNA produced only in cells that have been infected by viruses. “In theory, it should work against all viruses,” says Todd Rider, a senior staff scientist in Lincoln Laboratory’s Chemical, Biological, and Nanoscale Technologies Group who invented the new technology.
Because the technology is so broad-spectrum, it could potentially also be used to combat outbreaks of new viruses, such as the 2003 SARS (severe acute respiratory syndrome) outbreak, Rider says.
Other members of the research team are Lincoln Lab staff members Scott Wick, Christina Zook, Tara Boettcher, Jennifer Pancoast and Benjamin Zusman.
Few antivirals available
Rider had the idea to try developing a broad-spectrum antiviral therapy about 11 years ago, after inventing CANARY (Cellular Analysis and Notification of Antigen Risks and Yields), a biosensor that can rapidly identify pathogens. “If you detect a pathogenic bacterium in the environment, there is probably an antibiotic that could be used to treat someone exposed to that, but I realized there are very few treatments out there for viruses,” he says.
There are a handful of drugs that combat specific viruses, such as the protease inhibitors used to control HIV infection, but these are relatively few in number and susceptible to viral resistance.
Rider drew inspiration for his therapeutic agents, dubbed DRACOs (Double-stranded RNA Activated Caspase Oligomerizers), from living cells’ own defense systems.
When viruses infect a cell, they take over its cellular machinery for their own purpose — that is, creating more copies of the virus. During this process, the viruses create long strings of double-stranded RNA (dsRNA), which is not found in human or other animal cells.
As part of their natural defenses against viral infection, human cells have proteins that latch onto dsRNA, setting off a cascade of reactions that prevents the virus from replicating itself. However, many viruses can outsmart that system by blocking one of the steps further down the cascade.
Rider had the idea to combine a dsRNA-binding protein with another protein that induces cells to undergo apoptosis (programmed cell suicide) — launched, for example, when a cell determines it is en route to becoming cancerous. Therefore, when one end of the DRACO binds to dsRNA, it signals the other end of the DRACO to initiate cell suicide.
Combining those two elements is a “great idea” and a very novel approach, says Karla Kirkegaard, professor of microbiology and immunology at Stanford University. “Viruses are pretty good at developing resistance to things we try against them, but in this case, it’s hard to think of a simple pathway to drug resistance,” she says.
Each DRACO also includes a “delivery tag,” taken from naturally occurring proteins, that allows it to cross cell membranes and enter any human or animal cell. However, if no dsRNA is present, DRACO leaves the cell unharmed.
Most of the tests reported in this study were done in human and animal cells cultured in the lab, but the researchers also tested DRACO in mice infected with the H1N1 influenza virus. When mice were treated with DRACO, they were completely cured of the infection. The tests also showed that DRACO itself is not toxic to mice.
The researchers are now testing DRACO against more viruses in mice and beginning to get promising results. Rider says he hopes to license the technology for trials in larger animals and for eventual human clinical trials.
This work is funded by a grant from the National Institute of Allergy and Infectious Diseases and the New England Regional Center of Excellence for Biodefense and Emerging Infectious Diseases, with previous funding from the Defense Advanced Research Projects Agency, Defense Threat Reduction Agency, and Director of Defense Research & Engineering (now the Assistant Secretary of Defense for Research and Engineering). via web.mit.edu
Success! Functioning Anal Sphincter Grown in a Petri Dish
Eyes, sperm, you name it: these days, chances are someone’s cooking it up on a little slab of agar and gearing up to graft/sew/implant it in anything that comes near. Today’s body part is the anal sphincter, that handy little ring of muscle that maintains the separation between your insides and your outsides. Researchers grew them from cells, implanted them in mice, and compared the new sphincters’ function with the animals’, ah, native orifices. And apparently, they were quite satisfactory.
You young whippersnappers out there might not realize it, of course. But malfunctioning sphincters are a big, messy problem as you get older, and a lot of people suffering from fecal incontinence (including women recovering from births, which can put everything down there out of whack) could benefit from this research. Right now, Depends or surgery with high rates of complication are what people with damaged sphincters have to choose from, and the possibility of replacing the muscle is intriguing.
The major step forward made here is that these sphincters, which were grown in a circular mold from human muscle biopsy cells and mouse nerve cells, could, by virtue of those nerve cells, communicate with the animal’s nervous system, a level of functionality that had not previously been reached. The big-picture goal is to build new sphincters from patients’ own cells, which could then be implanted without the immune system kicking up a fuss.
Now that’s what I call progress.
Image: Wake Forest Institute of Regenerative Medicine (Khalil Bitar et al), via USAToday
TrES-2b is a Jupiter-sized planet located about 750 light-years from Earth. It reflects just 1% of the sunlight that reaches it, making it essentially one vast black sphere. In fact, it’s darker than just about any substance found on Earth. We’ve never observed anything remotely like this before.
The key concept here is albedo, also known as the reflection coefficient, which describes what percentage of the light that falls on a given surface is reflected back. Earth, for instance, has an albedo of about 30 to 35%, depending on cloud cover, which is why the Apollo astronauts were able to see Earth from the Moon - if our albedo was 0%, then our planet would essentially be invisible. And if our albedo was close to 100% - thanks to thermodynamics, no albedo can be a perfect 100% - we’d be the Sun.
Most planets in our solar system have an albedo that falls somewhere between about 25 and 50%. Jupiter, for instance, reflects back about a third of the sunlight that falls on it thanks to the presence of massive ammonia clouds. Those clouds are a major reason behind the gas giant’s high albedo.
That isn’t the case for TrES-2b, which is located just three million miles from its star. This heats the planet to nearly 2,000 degrees Fahrenheit, which rules out such clouds. Instead, its atmosphere is apparently composed entirely of light-absorbing chemicals, including some mix of vaporized sodium, potassium, and gaseous titanium oxide. Even then, astronomers are at something of a loss to fully explain the tremendous blackness of this strange planet.
Princeton astronomer David Spiegel describes the planet:
"It’s not clear what is responsible for making this planet so extraordinarily dark. However, it’s not completely pitch black. It’s so hot that it emits a faint red glow, much like a burning ember or the coils on an electric stove."
NASA’s Kepler spacecraft was able to detect slight variations in the amount of light bouncing off of TrES-2b. The planet is tidally locked around its star, meaning it moves around it star in much the same way our Moon moves around Earth. This means it also has distinct phases, which create those tiny differences in the amount of light reflected off of the planet - just six parts per million, by far the most subtle light change Kepler has ever had to detect.
As Spiegel and his colleague David Tipping point out in their paper, evocatively titled “Detection of visible light from the darkest world”, exoplanets like TrES-2b - the so-called Hot Jupiters - are supposed to be dark. Even so, we’ve never seen anything quite like TrES-2b before, and it’ll be interesting to see whether Kepler can turn up similarly dark planets in its data. Until then, I think it best to quote the Astronomer Royal, Sir Nigel Tufnel, who said of this strange world, “It’s like, how much more black could this be? And the answer is none. None more black.”
Read the original paper here. Artist’s impression by David A. Aguilar.
Back in April, the SETI Allen Telescope Array was shut down due to lack of funding. Now, the institute’s search for extraterrestrial life is set to resume, thanks in no small part to more than $200,000 in donations from thousands of fans.
"We’re not completely out of the woods yet, but everybody’s smiling here," the institute’s chief executive officer, Tom Pierson, told Cosmic Log’s Alan Boyle.
You can read more about the history of the SETI Institute, and the steps it’s taking to reduce the cost of searching for alien life, over at Boyle’s Cosmic Log blog.
Solar Storms Building Toward Peak in 2013, NASA Predicts
by Clara Moskowitz, SPACE.com Senior Writer
Date: 09 August 2011 Time: 05:06 PM ET
This image from the Solar Dynamics Observatory shows the X6.9 solar flare of Aug. 9, 2011 near the western limb (right edge) of the sun. CREDIT: NASA/SDO/Weather.com View full size image
Solar flares like the huge one that erupted on the sun early today (Aug. 9) will only become more common as our sun nears its maximum level of activity in 2013, scientists say.
Tuesday’s flare was the most powerful sun storm since 2006, and was rated an X6.9 on the three-class scale for solar storms (X-Class is strongest, with M-Class in the middle and C-Class being the weakest).
Flares such as this one could become the norm soon, though, as our sun’s 11-year cycle of magnetic activity ramps up, scientists explained. The sun is just coming out of a lull, and scientists expect the next peak of activity in 2013. The current cycle, called Solar Cycle 24, began in 2008.
"We still are on the upswing with this recent burst of activity," said Phil Chamberlin, a solar scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., who is a deputy project scientist for the agency’s Solar Dynamics Observatory, a sun-studying satellite that launched in February 2010. "We could definitely in the next year or two see more events like this; there’s a potential to see larger events as well." [Sun’s Wrath: Worst Solar Storms in History]
A more active sun
Earth got lucky with the most recent flare, which wasn’t pointed directly at Earth; therefore, it didn’t send the brunt of its charged particles toward us, but out into space. However, we may not be so fortunate in the future, experts warned.
"We’re in the new cycle, it is building and we’ll see events like this one," said Joe Kunches, a space scientist with the National Oceanic and Atmospheric Administration (NOAA)’s Space Weather Prediction Center. "They’ll be much more commonplace and we’ll get more used to them." [Stunning Photos of Solar Flares & Sun Storms]
Spacecraft such as the Solar Dynamics Observatory (SDO), which recorded amazing videos of the Aug. 9 solar flare, and other observatories will be vital in monitoring the sun during its active phase, researchers said.
How sun storms form
Storms brew on the sun when pent-up energy from tangled magnetic field lines is released in the form of light, heat and charged particles. This can create a brightening on the sun called a flare, and is also often accompanied by the release of a cloud of plasma called a coronal mass ejection (CME).
These ejections are the part we Earthlings have to worry about.
As the CME careens through space, it can send a horde of charged particles toward our planet that can damage satellites, endanger astronauts in orbit, and interfere with power systems, communications and other infrastructure on the ground.
"We’re well aware of the difficulties and challenges," Kunches told SPACE.com. "We know more about the sun than we ever have."
Can we predict solar storms?
When a big storm occurs, the Space Weather Prediction Center releases a warning to the U.S. Department of Homeland Security, emergency managers and agencies responsible for protecting power grids. Then power grids can distribute power and reduce their loads to protect themselves.
Still, scientists would like to offer more advanced warnings when big storms are headed our way.
"We’re being reactive, we’re not being proactive," Chamberlin said. "We don’t know how to predict these things, which would be nice."
Chamberlin said solar science has come a long way in recent years, though, and the goal of SDO and other NASA projects is to improve our understanding of the sun and our ability to forecast space weather.
Posted on August 9, 2011 - 04:29 by Emma Woollacott
The building blocks of DNA have been arriving here from meteorites in greater quantity than previously thought, lending weight to the idea that the seeds of life on Earth originated in space.
While certain components of DNA were first found in meteorites in the 1960s, scientists weren’t able to rule out the possibility that they originated from terrestrial contamination.
But a new analysis of a dozen meteorites has found that they contain the amino acids adenine and guanine - components of DNA nucleobases - as well as other molecules that are highly unlikely to have originated on Earth.
In two of the meteorites studied, the team found for the first time trace amounts of three molecules related to nucleobases that are almost never found in terrestrial life.
These nucleobase-related molecules, called nucleobase analogs, form the first strong evidence that the compounds in the meteorites came from space.
"You would not expect to see these nucleobase analogs if contamination from terrestrial life was the source, because they’re not used in biology," says NASA astrobiologist Michael Callahan.
"However, if asteroids are behaving like chemical ‘factories’ cranking out prebiotic material, you would expect them to produce many variants of nucleobases, not just the biological ones, because of the wide variety of ingredients and conditions in each asteroid."
This conclusion’s corroborated by a comparison of the meteorites with the Antarctic ice in which they were found.
Not only were the amounts of nucleobases found in the ice much lower than in the meteorites, none of the nucleobase analogs were detected in the ice sample. Similarly, a soil sample collected near one of the non-Antarctic meteorite’s landing sites also lacked the nucleobase analog molecules found in the meteorite.
The nucleobases appear to have been built within the meteorites through a non-biological process. Indeed, the team was able to replicate this in the lab through chemical reactions containing hydrogen cyanide, ammonia, and water.
"For the first time, we have three lines of evidence that together give us confidence these DNA building blocks actually were created in space," says Callahan.
The signatures of a bubble collision at various stages in the analysis pipeline. A collision (top left) induces a temperature modulation in the CMB temperature map (top right). The ‘blob’ associated with the collision is identified by a large needlet response (bottom left), and the presence of an edge is highlighted by a large response from the edge detection algorithm (bottom right). In parallel with the edge-detection step, we perform a Bayesian parameter estimation and model selection analysis.
3 August 2011
The theory that our universe is contained inside a bubble, and that multiple alternative universes exist inside their own bubbles – making up the ‘multiverse’ – is, for the first time, being tested by physicists.
Two research papers published in Physical Review Letters and Physical Review D are the first to detail how to search for signatures of other universes. Physicists are now searching for disk-like patterns in the cosmic microwave background (CMB) radiation - relic heat radiation left over from the Big Bang – which could provide tell-tale evidence of collisions between other universes and our own.
Many modern theories of fundamental physics predict that our universe is contained inside a bubble. In addition to our bubble, this `multiverse’ will contain others, each of which can be thought of as containing a universe. In the other ‘pocket universes’ the fundamental constants, and even the basic laws of nature, might be different.
Until now, nobody had been able to find a way to efficiently search for signs of bubble universe collisions - and therefore proof of the multiverse - in the CMB radiation, as the disc-like patterns in the radiation could be located anywhere in the sky. Additionally, physicists needed to be able to test whether any patterns they detected were the result of collisions or just random patterns in the noisy data.
A team of cosmologists based at University College London (UCL), Imperial College London and the Perimeter Institute for Theoretical Physics has now tackled this problem.
“It’s a very hard statistical and computational problem to search for all possible radii of the collision imprints at any possible place in the sky,” says Dr Hiranya Peiris, co-author of the research from the UCL Department of Physics and Astronomy. “But that’s what pricked my curiosity.”
The team ran simulations of what the sky would look like with and without cosmic collisions and developed a ground-breaking algorithm to determine which fit better with the wealth of CMB data from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP). They put the first observational upper limit on how many bubble collision signatures there could be in the CMB sky.
Stephen Feeney, a PhD student at UCL who created the powerful computer algorithm to search for the tell-tale signatures of collisions between “bubble universes”, and co-author of the research papers, said: “The work represents an opportunity to test a theory that is truly mind-blowing: that we exist within a vast multiverse, where other universes are constantly popping into existence.”
One of many dilemmas facing physicists is that humans are very good at cherry-picking patterns in the data that may just be coincidence. However, the team’s algorithm is much harder to fool, imposing very strict rules on whether the data fits a pattern or whether the pattern is down to chance.
Dr Daniel Mortlock, a co-author from the Department of Physics at Imperial College London, said: “It’s all too easy to over-interpret interesting patterns in random data (like the ‘face on Mars’ that, when viewed more closely, turned out to just a normal mountain), so we took great care to assess how likely it was that the possible bubble collision signatures we found could have arisen by chance.”
The authors stress that these first results are not conclusive enough either to rule out the multiverse or to definitively detect the imprint of a bubble collision. However, WMAP is not the last word: new data currently coming in from the European Space Agency’s Planck satellite should help solve the puzzle.
Discovery of first Trojan asteroid found in Earth’s orbit
Studying images compiled by NASA, an astronomer from The University of Western Ontario has proved the existence of the first Trojan asteroid found to share Earth’s orbit. The findings of Paul Wiegert and his colleagues at Athabasca University and the Canada-France-Hawaii Telescope were published today as the cover story for the July 28 issue of distinguished journal, Nature.
A Trojan asteroid shares an orbit with a larger planet or moon, in this case Earth, but does not collide with it because it follows the same orbital path. Before this discovery, only the planets Jupiter, Neptune and Mars were known to harbor these asteroids named for the soldiers of the ancient war immortalized by Homer in The Iliad and The Odyssey.
“Like a pair of dancers performing a complicated tango, the asteroid moves in an elaborate path that brings it sometimes closer and sometimes farther from us,” says Wiegert, a professor in Western’s Department of Physics and Astronomy. “The Earth and the asteroid remain in sync however, with the asteroid always preceding the Earth as they both move around the Sun.”
Images of the asteroid were then taken by Christian Veillet, Executive Director of the Canada-France-Hawaii Telescope in Hawaii, to refine the asteroid’s orbit once it was favorably placed in the night sky. Based on these new images, Wiegert was able to create computer simulations of Asteroid 2010 TK7, which confirmed the Trojan character of its motion.
“These asteroids are very interesting as individual members of the near-Earth asteroid population but they also tell us a lot about how the Earth and asteroids interact gravitationally at a distance,” says Wiegert. “Because this asteroid is a Trojan asteroid, it interacts with the Earth in a very special way allowing us a unique opportunity to study near-Earth asteroids.”
Trojan Asteroid simulation videos
The camera moves to give a clearer view of the 3D shape of the orbit of 2010 TK7. Note: This clip is only illustrative of the orbits involved. In particular, the number of loops has been reduced for easier visibility, and the sizes of the Sun, Earth and the asteroid have been exaggerated for the same reason. As a result, the asteroid appears to pass much closer to the Earth than it does in reality.
The Sun is at the centre of the image, the Earth at the bottom. The path of the asteroid is shown in green: the spaces between loops have been expanded for clarity. Note: This clip is only illustrative of the orbits involved. In particular, the number of loops has been reduced for easier visibility, and the sizes of the Sun, Earth and the asteroid have been exaggerated for the same reason. As a result, the asteroid appears to pass much closer to the Earth than it does in reality.
Ancient black hole contains 100,000 Suns worth of water
A distant, hyper-energetic black hole known as a quasar contains the largest reserve of water in the known universe, equivalent to 140 trillion times the water on Earth. The solution to our water crisis is only 12 billion light-years away!
Technically speaking, quasars occur when giant black holes suck in huge amounts of gas and dust, spewing back out equally immense amounts of energy. This particular quasar is APM 08279+5255, whose black hole is 20 billion times the mass of the Sun and produces enough energy to power a quadrillion copies of our star. It dates back to the early days of the universe, just 1.6 billion years after the Big Bang. That makes this water the earliest in the known cosmos.
Of course, we’re not talking about a gargantuan space ocean here, cool as that might be. The water is in its gaseous, vapor form, and it’s distributed over hundreds of light-years, with an average temperature of just minus 63 degrees Fahrenheit and an average density 300 trillion times less than that of Earth’s atmosphere. That may sound kind of unimpressive, but it’s all about perspective - this particular cosmic reservoir is about five times hotter and 10 to 100 times denser than the water reserves you find in the Milky Way and other galaxies.
Speaking of which, just to put this all in perspective, there’s about 4,000 times the amount of water in this quasar than in our entire galaxy combined. This water has an equivalent mass of 100,000 Suns or 34 billion Earths. And the water isn’t just standing around being gaseous, as a Carnegie Institution press release explains:
The large quantity of water vapor in the quasar indicates that it is bathing the gas in both X-rays and infrared radiation. The interaction between the radiation and water vapor reveals properties of how the gas is influenced by the quasar. For example, analyzing the water vapor shows how the radiation heats the rest of the gas. Furthermore, measurements of the water vapor and of other molecules, such as carbon monoxide, suggest that there is enough gas to enable the black hole to grow to about six times its size. Whether or not this has happened is unclear, the astronomers say, since some of the gas could condense into stars or being ejected from the quasar.
Mystery Solved: Water on Saturn Comes From Icy Moon 'Rain'
by Denise Chow, SPACE.com Staff Writer
Date: 26 July 2011 Time: 01:36 PM ET
At least four distinct plumes of water ice spew out from the south polar region of Saturn’s moon Enceladus. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 25, 2009. CREDIT: NASA/JPL/Space Science Institute View full size image
An icy moon around Saturn is showering rain water onto its home planet, creating a vast halo of water vapor around the ringed world, a new study finds.
The discovery means that Enceladus, Saturn’s sixth-largest moon, is the only moon in the solar system known to influence the chemical composition of its parent planet, researchers said. It also solves a 14-year mystery that had scientists puzzled over the source of the water in Saturn’s upper atmosphere.
"There is no analogy to this behavior on Earth," said study leader Paul Hartogh, of the Max Planck Institute for Solar System Research in Germany, in a statement. "No significant quantities of water enter our atmosphere from space. This is unique to Saturn."
Enceladus has a frigid, icy surface but an active interior, particularly at its south pole. In this dynamic region, geothermal activity is concentrated at four trenches that are dubbed “tiger stripes,” because of their distinctive surface markings. [Photos: The Rings and Moons of Saturn]
These fissures, which measure approximately 80 miles (130 kilometers) long and 1.2 miles (2 km) wide, form icy geysers that spew plumes of water vapor into space. Enceladus expels roughly 550 pounds (250 kilograms) of water vapor every second through its tiger stripe jets.
Another ring around Saturn
Observations from the European Space Agency’s Herschel space observatory revealed that this water raining from Enceladus creates a doughnut-shaped ring of water vapor around Saturn.
The total width of the water vapor ring is more than 10 times the radius of Saturn, yet it is only about one Saturn radius thick. Enceladus’ elliptical orbit means that the moon’s distance from Saturn varies as ittravels around the ringed planet. But, Herschel’s observations indicate that Enceladus’ jets consistently replenish the water vapor ring throughout its orbit.
Despite the size of the ring, it had not been detected prior to now because water vapor is transparent to visible light, researchers said. Yet, Herschel’s eyes, which are tuned to infrared wavelengths, were able to spot the curious feature.
"These are observations that only Herschel can make," said Göran Pilbratt, ESA Herschel project scientist, in a statement. "ESA’s Infrared Space Observatory found the water vapor in Saturn’s atmosphere. Then NASA/ESA’s Cassini/Huygens mission found the jets of Enceladus. Now Herschel has shown how to fit all these observations together."
A mystery solved
Astronomers have known that Saturn’s atmosphere holds traces of gaseous water in its deepest layers, but the presence of water in the planet’s upper atmosphere had been a mystery. The phenomenon was first reported in 1997 by teams using ESA’s Infrared Space Observatory, but until now, the source of the water was unknown.
Computer models based on the latest findings from Herschel estimate that between three to five percent of the water spewed by Enceladus ends up falling onto Saturn.
While most of Enceladus’ rain is either lost in space, freezes on Saturn’s rings, or potentially even falls onto the planet’s other moons, what does reach the ringed planet is sufficient enough to explain the water in its upper atmosphere.
The water vapor is also responsible for the production of other chemical compounds bearing oxygen, such as carbon dioxide, scientists said.
Eventually, water in the planet’s upper atmosphere will travel to lower levels, where the small amounts will condense into tiny clouds that are ultimately not observable, they added.
An imprint of an owl is seen on a window where a bird apparently crashed in Kendal, England, on July 12. The homeowner found no sign of the owl and assumed the bird flew off — startled but unharmed. Experts say the white mark left on the glass are from the bird’s powder down, a part of a bird’s feathery coat composed of fine dust particles of keratin. via Mother Nature Network
After speeding through the solar system for four years with ion thrusters, Dawn is now poised to enter orbit around Vesta later tonight, where it will circle for a year and study the giant space rock’s composition. Vesta’s gravitational pull is expected to capture Dawn around 10 p.m. Pacific time/ 1 a.m. Saturday Eastern time, according to NASA.
Although it lives in the asteroid belt between Mars and Jupiter, the monstrous, 330-mile-wide Vesta is really more of a protoplanet than an asteroid. Most space rocks in its neighborhood are a third of its size, and Vesta has a rocky composition like that of Venus, Earth and Mars, with a core, mantle and crust.
It’s distinct from the other 540,000-odd objects that are considered “minor planets,” the objects that orbit the sun but aren’t planets or comets. But it’s too small to be considered a dwarf planet, unlike Ceres — the Dawn spacecraft’s next destination in 2015, by the way.
Scientists think that Vesta could have been the fifth rocky planet, behind Mars, but it never properly coalesced. It’s probably the fault of Jupiter, which knocked away other objects that Vesta could have collided with to form a larger, denser orb. Vesta has actually been minimized through collisions with other objects, which have knocked off bits of it to form Vestoids, as this NASA Science story explains.
Dawn is designed to study several key features at Vesta, which scientists hope will help explain how it formed — or did not form, as it were. It will map the asteroid’s terrain, gravity field and interior structure, partly by scrutinizing a huge crater at its south pole which is currently illuminated by sunlight.
After a year of observations, Dawn will fire its ion thrusters again and make its way to Ceres for arrival in 2015.
Alasdair Wilkins — Computers may be naturally fluent in binary, but how might they fare with learning human languages? Computers were tested by playing the gameCivilization. Random chance let them win about half the time…but then they started reading the instruction manual.
MIT researchers gave their AI this particular challenge because winning a game likeCivilization is so complex. At first, the computer only had the most limited of knowledge, as a press release explains:
It begins with virtually no prior knowledge about the task it’s intended to perform or the language in which the instructions are written. It has a list of actions it can take, like right-clicks or left-clicks, or moving the cursor; it has access to the information displayed on-screen; and it has some way of gauging its success, like whether the software has been installed or whether it wins the game. But it doesn’t know what actions correspond to what words in the instruction set, and it doesn’t know what the objects in the game world represent.
From that starting point, the computer eventually managed to win the game about 46% of the time. It reached that success rate by playing the game a bunch of times and being able to gauge how successful its different actions were, maximizing the actions that led to victory and minimizing those that led to defeat. In and of itself, that’s moderately impressive but nothing too amazing. But then the researchers gave the computer access to the instruction manual.
Researcher S.R.K. Branavan explains:
"Games are used as a test bed for artificial-intelligence techniques simply because of their complexity. Every action that you take in the game doesn’t have a predetermined outcome, because the game or the opponent can randomly react to what you do. So you need a technique that can handle very complex scenarios that react in potentially random ways. [Instruction manuals are a] very open text. They don’t tell you how to win. They just give you very general advice and suggestions, and you have to figure out a lot of other things on your own."
So then, if the AI was going to get anything useful out of the instruction manuals, then it really would have to understand what they were saying and figure out how to apply them. And the results? The computer’s success rate skyrocketed from 46% to 79%, an absolutely massive leap. According to the researchers, that suggests computers really can learn meaning of words through interaction with the environment around them.
Brown University computer scientist Eugene Charniak backs up just how impressive this finding is:
"If you’d asked me beforehand if I thought we could do this yet, I’d have said no. You are building something where you have very little information about the domain, but you get clues from the domain itself."
The human genome contains a million years worth of population data
Alasdair Wilkins — Our genes don’t just help determine who we are — they also preserve an incredibly ancient record of who our ancestors were. Our genomes can actually reveal human population sizes dating all the way back to before humans even existed.
Richard Durbin of the Wellcome Trust Sanger Institute and Heng Li of the Broad Institute examined the handful of complete human genome sequences. Specifically, they examined how the differences between how particular genes from mothers and fathers were expressed — many differences in gene expression would suggest the family lines diverged a long time ago, while relatively few differences would indicate the two were closely related in the recent past.
Li goes further into just how this all works:
"This elegant tool provides opportunities for further research to enable us to learn more about population history," says co-author Heng Li, from the Sanger Institute. "Each human genome contains information from the mother and the father, and the differences between these at any place in the genome carry information about its history. Since the genome sequence is so large, we can combine the information from tens of thousands of different places in the genome to build up a composite history of the ancestral contributions to the particular individual who was sequenced."
Durbin explains some of the more remarkable findings of this genomic archaeology:
"Using this algorithm, we were able to provide new insights into our human history. First, we see an apparent increase in effective human population numbers around the time that modern humans arose in Africa over 100,000 years ago. Second, when we look at non-African individuals from Europe and East Asia, we see a shared history of a dramatic reduction in population, or bottleneck, starting about 60,000 years ago, as others have also observed. But unlike previous studies we also see evidence for continuing genetic exchange with African populations for tens of thousands of years after the initial out-of-Africa bottleneck until 20,000 to 40,000 years ago.
"Previous methods to explore these questions using genetic data have looked at a subset of the human genome. Our new approach uses the whole sequence of single individuals, and relies on fewer assumptions. Using such techniques we will be able to capitalize on the revolution in genome sequencing and analysis from projects such as The 1000 Genomes Project, and, as more people are sequenced, build a progressively finer detail picture of human genetic history."
Amazingly, the team reconstructed a million years worth of population history from just four male genomes, which came from China, Korea, Europe, and West Africa respectively. It appears that humans remained more or less a single global population until about 60,000 years ago, at which point our numbers in Europe and East Asia crashed to only a tenth of their previous amount.
While versions of this method have been used before, reconstructing populations on this sort of scale using genomics have never before been attempted. Ryan Gutenkunst of the University of Arizona explains why this is such an impressive result:
"The method is really spectacular. Previous methods have taken averages across the genome, but here they are looking at variation from one location to another location and getting good results from even a single individual."