When Galaxies Collide: How the First Super-Massive Black Holes Were Born

Astronomers believe they have discovered the origin of our universe's first super-massive black holes, which formed some 13 billion years ago.
The discovery fills in a missing chapter of our universe's early history, and could help write the next chapter -- in which scientists better understand how gravity and dark matter formed the universe as we know it.

In the journal Nature, Ohio State University astronomer Stelios Kazantzidis and colleagues describe computer simulations in which they modeled the evolution of galaxies and black holes during the first few billion years after the Big Bang.

Our universe is thought to be 14 billion years old. Other astronomers recently determined that big galaxies formed much earlier in the universe's history than previously thought -- within the first 1 billion years, Kazantzidis explained.

These new computer simulations show that the first-ever super-massive black holes were likely born when those early galaxies collided and merged together.

"Our results add a new milestone to the important realization of how structure forms in the universe," he said.

For more than two decades, the prevailing wisdom among astronomers has been that galaxies evolved hierarchically -- that is, gravity drew small bits of matter together first, and those small bits gradually came together to form larger structures.

Kazantzidis and his team turn that notion on its head.

"Together with these other discoveries, our result shows that big structures -- both galaxies and massive black holes -- build up quickly in the history of the universe," he said. "Amazingly, this is contrary to hierarchical structure formation."

The paradox is resolved once one realizes that dark matter grows hierarchically, but ordinary matter doesn't," he continued. "The normal matter that makes up visible galaxies and super-massive black holes collapses more efficiently, and this was true also when the universe was very young, giving rise to anti-hierarchical formation of galaxies and black holes."

For Kazantzidis and other astronomers, our Milky Way galaxy is small compared to others.

So when it comes to normal matter, big bits like giant galaxies and super-massive black holes come together quickly, and smaller bits like our own Milky Way galaxy -- and the comparatively small black hole at its center -- form more slowly. The galaxies that formed those first super-massive black holes are still around, Kazantzidis added.

"One of them is likely our neighbor in the Virgo Cluster, the elliptical galaxy M87," he said. "The galaxies we saw in our simulation would be the biggest galaxies known today, about 100 times the size of the Milky Way. M87 fits that description."

They started their simulations with two giant primordial galaxies -- ones made of the kinds of stars that were around at the beginning of the universe. Astronomers believe that back then, all stars would have been much more massive than present-day stars -- up to 300 times the mass of our sun.

Then the astronomers simulated the galaxies colliding and merging together.

The astronomers were able to make their discovery because they used supercomputers to provide a high-resolution view of what happened next.

Previous simulations showed details of the merged galaxy down to only about 300 light-years across. A light-year is the distance that light travels in year, about six trillion miles.

These new simulations contained features that were 100 times smaller, and revealed details in the heart of the merged galaxies on a scale of less than a light year.

The astronomers saw two things happen. First, gas and dust in the center of the galaxies condensed to form a tight nuclear disk. Then the disk became unstable, and the gas and dust contracted again, to form an even denser cloud that eventually spawned a super-massive black hole.

The implications for cosmology are far-reaching, Kazantzidis said.

"For example, the standard idea -- that a galaxy's properties and the mass of its central black hole are related because the two grow in parallel -- will have to be revised. In our model, the black hole grows much faster than the galaxy. So it could be that the black hole is not regulated at all by the growth of the galaxy. It could be that the galaxy is regulated by the growth of the black hole."

He and his cohorts also hope that their work will aid astronomers who are searching the skies for direct evidence of Einstein's theory of general relativity: gravitational waves.

According to general relativity, any ancient galaxy mergers would have created massive gravitational waves -- ripples in the space-time continuum -- the remnants of which should still be visible today.

New gravitational wave detectors, such as NASA's Laser Interferometer Space Antenna, were designed to detect these waves directly, and open a new window into astrophysical and physical phenomena that cannot be studied in other ways.

Scientists will need to know how super-massive black holes formed in the early universe and how they are distributed in space today in order interpret the results of those experiments. The new computer simulations should provide a clue.

Coauthors on the Nature paper include Lucio Mayer and Simone Callegari of the Institute for Theoretical Physics at the University of Zürich, and Andres Escala, formerly of Stanford University and now at the Universidad de Chile.

This work was funded by the Swiss National Science Foundation, the Center for Cosmology and Astro-Particle Physics at Ohio State, and the Kavli Institute for Particle Astrophysics at Stanford University. Simulations were performed on the Zbox3 supercomputer at the University of Zürich and on the Brutus cluster at ETH Zürich.

Electricity Collected from the Air Could Become the Newest Alternative Energy Source

Imagine devices that capture electricity from the air ― much like solar cells capture sunlight ― and using them to light a house or recharge an electric car. Imagine using similar panels on the rooftops of buildings to prevent lightning before it forms. Strange as it may sound, scientists already are in the early stages of developing such devices, according to a report presented at the 240th National Meeting of the American Chemical Society (ACS).
"Our research could pave the way for turning electricity from the atmosphere into an alternative energy source for the future," said study leader Fernando Galembeck, Ph.D. His research may help explain a 200-year-old scientific riddle about how electricity is produced and discharged in the atmosphere. "Just as solar energy could free some households from paying electric bills, this promising new energy source could have a similar effect," he maintained.

"If we know how electricity builds up and spreads in the atmosphere, we can also prevent death and damage caused by lightning strikes," Galembeck said, noting that lightning causes thousands of deaths and injuries worldwide and millions of dollars in property damage.

The notion of harnessing the power of electricity formed naturally has tantalized scientists for centuries. They noticed that sparks of static electricity formed as steam escaped from boilers. Workers who touched the steam even got painful electrical shocks. Famed inventor Nikola Tesla, for example, was among those who dreamed of capturing and using electricity from the air. It's the electricity formed, for instance, when water vapor collects on microscopic particles of dust and other material in the air. But until now, scientists lacked adequate knowledge about the processes involved in formation and release of electricity from water in the atmosphere, Galembeck said. He is with the University of Campinas in Campinas, SP, Brazil.

Scientists once believed that water droplets in the atmosphere were electrically neutral, and remained so even after coming into contact with the electrical charges on dust particles and droplets of other liquids. But new evidence suggested that water in the atmosphere really does pick up an electrical charge.

Galembeck and colleagues confirmed that idea, using laboratory experiments that simulated water's contact with dust particles in the air. They used tiny particles of silica and aluminum phosphate, both common airborne substances, showing that silica became more negatively charged in the presence of high humidity and aluminum phosphate became more positively charged. High humidity means high levels of water vapor in the air ― the vapor that condenses and becomes visible as "fog" on windows of air-conditioned cars and buildings on steamy summer days.

"This was clear evidence that water in the atmosphere can accumulate electrical charges and transfer them to other materials it comes into contact with," Galembeck explained. "We are calling this 'hygroelectricity,' meaning 'humidity electricity'."

In the future, he added, it may be possible to develop collectors, similar to the solar cells that collect the sunlight to produce electricity, to capture hygroelectricity and route it to homes and businesses. Just as solar cells work best in sunny areas of the world, hygroelectrical panels would work more efficiently in areas with high humidity, such as the northeastern and southeastern United States and the humid tropics.

Galembeck said that a similar approach might help prevent lightning from forming and striking. He envisioned placing hygroelectrical panels on top of buildings in regions that experience frequent thunderstorms. The panels would drain electricity out of the air, and prevent the building of electrical charge that is released in lightning. His research group already is testing metals to identify those with the greatest potential for use in capturing atmospheric electricity and preventing lightning strikes.

"These are fascinating ideas that new studies by ourselves and by other scientific teams suggest are now possible," Galembeck said. "We certainly have a long way to go. But the benefits in the long range of harnessing hygroelectricity could be substantial."

CNPq (National Council for Scientific and Technological Development) and FAPESP (The State of São Paulo Research Foundation) funded the study.

Chilean Miners Could Be Stuck for Months

* Rescue teams are getting ready to launch a months-long operation to recover 33 trapped miners.
* The miners sent a note through a bore hole saying that all 33 were alive and well.

Chilean rescue teams prepared to launch a potentially months-long bid Monday to retrieve 33 miners found alive and in apparently good health after more than two weeks trapped deep underground.

A camera sent down a bore hole showed the men shirtless, sweaty and happy despite chief rescue engineer Andres Sougarret saying it would take "at least 120 days" to carve out a new shaft after the mine's entrance collapsed.

Chilean President Sebastian Pinera stunned his nation and the world Sunday, when he announced that a note sent through a bore hole at the San Jose gold and copper mine near the city of Copiapo showed all 33 miners were alive.

"All 33 of us are well inside the shelter," said the note, handwritten in bold red capital letters.

Pinera read the message aloud and waved it in the air, as friends and relatives wept with joy outside the northern Chilean mine whose entrance collapsed on August 5, trapping the workers inside.

His words came after days of fading hopes at the mine, located 800 kilometers (500 miles) north of Santiago.

A camera lowered down the bore hole drilled 700 meters (2,300 feet) into the earth showed the miners sweaty and shirtless in the hot shelter, but in apparently good condition and high spirits.

"Many of them approached the camera and put their faces right up against it, like children, and we could see happiness and hope in their eyes," Pinera said, adding that the images "gave me a lot of happiness and faith that this is going to end well."

National Emergency Office regional director Carlos Garcia said the trapped miners had some water and lights and that in the next few hours they would get fresh supplies of food and water, which they would have to ration carefully.

Garcia said relatives would be soon allowed to speak with their loved ones through a cable dropped down the drill bore.

As word spread that the miners were alive after 17 days below ground, drivers honked their horns in the capital Santiago and thousands of people gathered in other cities to celebrate and wave national flags.

Until Sunday, there had been no sign that the miners had survived their ordeal.

But then came two notes in a plastic bag attached to a line that had been lowered through the narrow shaft drilled into the shelter.

Mining Minister Laurence Golborne said the first note they pulled out was a letter from Mario Gomez, one of the trapped miners, to his wife Liliana.

"Dear Liliana, I'm well, thank God. I hope to get out soon. Have patience and faith. I haven't stopped thinking about all of you for a single moment," Gomez wrote.

One of the most experienced miners inside the shelter, Gomez said "a little water" was trickling down into the shelter and that for days the drilling machines could be heard clearly from above.

"We're hearing the drilling machine. Let's hope it gets here this time... I'm sure we'll get out of here alive. I hope to talk to you later," he added.

When rescuers drilling a shaft into the area finally broke through Sunday, they pulled out Gomez's letter along with another note, wrapped in a plastic bag and bound with rubber bands, said Mining Minister Laurence Golborne.

The second letter, which was read aloud by President Pinera, confirmed that all 33 miners were alive.

Rescuers said the miners would have to assist in their own release by clearing debris away from the hole beneath ground as drillers worked from above.

Friends and family at the site celebrated the news by cheering and waving a Chilean flag that had been found among the debris left by the earthquake and tsunami that devastated central Chile on February 27.

"They'll come out thin and dirty, but whole and strong, because the miners have shown they have courage and mettle, which is what has kept them together," Pinera said, choking with emotion.

Deep Water Dead Zone Predicted in the Gulf

* A new study predicts that a dead zone is likely to form at least 3,200 feet below the ocean's surface near the Deepwater Horizon oil spill.
* The zone is deep enough it is unlikely to affect fisheries.
* It will probably dissipate within about two years.
* Giant Underwater Oil Plume Found in Gulf of Mexico
* Nearly 80 Percent of Spilled Oil Still Threatens Gulf

The oil gusher on the Gulf seabed may be stopped, but much of the spilled oil still lurks in a plume of oil and dissolved methane gas 3,200-4,300 feet below the surface.

New research predicts that this plume will likely create a low-oxygen "dead zone" inhospitable to life in these deep waters, as microbes consume the oil and gas entrained in the plume.

The cold temperatures in the plume will slow the growth of the microbes compared to microbes acting at the surface. Because of this slower growth, the team predicts that it will be sometime in the fall before the oxygen levels hit their minimum.

But weak currents at that depth mean that the low oxygen levels may persist for a long time, with little mixing to bring in oxygenated waters: the team estimates it will be a couple of years before the oxygen levels return to normal.

The findings, now in press at the journal Geophysical Research Letters, predict that the zone will be similar in size to the well-known seasonal dead zone at the mouth of the Mississippi River caused by nutrient runoff upriver, though the new zone will remain within about 100 kilometers (62 miles) of the spill site.

"The area of the seasonal dead zone on the shelf is much larger, but it's much thinner," said study author Robert Hallberg of the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory in Princeton, NJ. "This one is a smaller area, but it's thick. It's still a small area compared to the Gulf of Mexico."

Many researchers have been speculating that the deepwater plume would create a dead zone as microbes ate the undersea oil and gas, consuming oxygen in the process. The new work combines the best estimates for how much oil was released with detailed models of ocean currents and information about typical microbial oil degradation rates to show that the conditions in the Gulf should, indeed, produce one.

Unlike the seasonal dead zone, which occurs in shallow waters, the oil-caused zone will be deep enough that fisheries shouldn't be affected. "I'm not expecting that this is going to have really dire consequences for people," Hallberg said. "There may be consequences for deep ecosystems."

"It's almost a separate ocean down there," agreed Monty Graham of the Dauphin Island Sea Lab in Alabama, who observed oxygen depletion in shallower waters following the spill. "That doesn't mean it's not important for diversity. We don't know the impact on the deep-diving marine mammals that might be going down searching for food."

While this study predicts oxygen depletion near the spill site, plume measurements made in June and published in Science last week showed very little oxygen consumption by microbial oil degradation.

"On the face of it, it might appear to be in contradiction to what we are saying," Hallberg said. "but if you take into account the temperature, the oxygen depletion should be peaking in the fall. Those observations from June may have been taken too soon and too close to the source so that the oxygen drawdown may not have been realized yet."

Another possibility, Graham said, is that the oil degradation rate estimates that the team used in their simulations may not match those of the actual microbial community in the plume. "It could be a time lag difference that the community of microbes hasn't established itself and therefore it's not operating at its maximum efficiency."

The study also provided information about the spill's toxicity by estimating the concentrations of various oil components in the deepwater plume over time.

"We weren't finding widespread concentrations of the oil that would be acutely toxic at the level that kills organisms over a couple of days," Hallberg said.

"I am less worried about the hypoxia than I am about the potential chronic effects of these hydrocarbons on the organisms and larvae," said Nancy Kinner , head of the Center for Spills in Environment at the University of New Hampshire in Durham.

"What we really don't know is if you have a low dose -- a low concentration in the water for a long exposure -- what's the chronic impact going to be?"

Hallberg agreed. "We know that compounds like toluene and benzene are regulated as known human carcinogens. You could imagine that there could be something similar for marine organisms, or something that affects development, or something that doesn't actually kill them. That's something where I think there's going to be a lot of research in the coming year."

Diamonds Are a Supercomputer's Best Friend

* Diamonds sheets patterned with thousands of nitrogen atoms could be the basis for a supercomputer.
* Quantum computers could solve currently intractable problems in cryptography and drug development.
* Diamond Oceans Possible on Uranus, Neptune
* Flawless Diamond To Create Powerful Lasers


Diamond sheets filled with holes could be the key to the next generation of supercomputers.

Scientists in California have used commercially available technology to pattern large sheets of diamonds with tiny, nitrogen-filled holes. The nitrogen-vacancy diamonds, as the sheets are called by scientists, could store millions of times more information than current silicon-based systems and process that information dozens of times faster.

Exactly how diamond-based computing would be used has yet to be determined, but applications could range from designing more efficient silicon-based computers to drug development and cryptography.

Nitrogen has been in diamonds for as long as their have been diamonds; it's why some diamonds have a yellow hue. For years scientists have used these natural, nitrogen-infused diamonds to study various aspects of quantum mechanics.

"We've used well-known techniques to create atomic-size defects in otherwise perfect diamonds," said David Awschalom, a scientist at the University of California, Santa Barbara and co-author of a new article in the journal ACS Nano Letters.

A supercomputer based on quantum mechanics requires more precision than nature can provide, so scientists have searched for a way to artificially implant arrays of precisely patterned nitrogen holes inside sheets of diamond.

Scientists from the University of California, Santa Barbara, along with colleagues from the Lawrence Berkeley National Laboratory, created such an array by using an ion beam to first knock out two carbon atoms, and then replace them with one nitrogen atom. In one second, the scientists could inject about 4,000 glowing nitrogen atoms. In about one minute, the scientists had patterned several inches of flat diamond.

The scientists didn't use any overly complicated techniques to accomplish this. "You can buy it online, send it to another company for the patterning, and then explore it yourself," said Awschalom, whose students did exactly that to demonstrate the ease of the technology.

The key to a diamond-based quantum mechanical computer is an extra electron in the hole. In a traditional computer, information is encoded as either a "0" or a "1." In a diamond-based quantum computer, information could be stored in the spin of that electron. This means information could be stored as not only a "0" or "1," but also the direction the electron is spinning.

An exact number is hard to come by, but scientists say this would dramatically increase the computing power compared with existing silicon computers.

Diamonds likely wouldn't replace the silicon used in today's consumer computers, said Ray Beausoleil, a fellow in Information and Quantum Systems at HP. "A quantum computer won't help you add two numbers faster," said Beausoleil.

However, that doesn't mean consumers won't benefit from a diamond-based quantum computer. What it will do is help model certain extremely complex problems, says Beausoleil and David DiVincenzo, a scientist at IBM who is also familiar with the Nano Letters article.

"This points to the fruitful end of a very long search of all the things that you could put in diamond to make it electronically active," said DiVincenzo.

Diamonds aren't a sure bet for a quantum computer, said DiVincenzo, but they're certainly in the running because of this research.

"Snot Otter" Sperm to Save Giant Salamander?

It may be a shot in the dark, but freezing sperm is one of the last chances to save the hellbender, North America's biggest salamander, conservationists say.

Hellbenders—also known as snot otters and devil dogs—have dwindled throughout their range, which once encompassed streams from northeastern Arkansas to New York.

The 2.5-foot-long (0.7-meter-long) amphibians have declined by 80 to 90 percent in most of their traditional watersheds in recent decades, and healthy populations now haunt only isolated pockets of southern Appalachia (see map) and Pennsylvania, said Dale McGinnity, curator of reptiles at Nashville Zoo.

All of the states in the hellbender's range have protected the species, and the U.S. Fish and Wildlife Service is currently reviewing whether to give the hellbender federal protection, McGinnity said.

The reasons for their decline is unknown, but it's likely environmental contaminants such as pesticides are harming the creatures via their highly permeable skin, he said.

To make matters worse, hellbenders don't seem to be breeding much in the wild, he said, possibly because human-made pollutants containing synthetic hormones are damaging the amphibians' reproductive systems. Pollutants may also be harming the species' eggs or larvae.

As a result, there are apparently very few wild hellbenders in existence, leaving mostly aged individuals—the amphibians live at least 30 years and could live much longer.

The hellbender's decline spurred an international team to collect sperm from some captive salamanders in September 2009 for cryopreservation, a common zoo practice that freezes sperm without damaging its cell membranes.

Though several zoos have put a "great deal of effort" into breeding the amphibians in captivity, none has been particularly successful, McGinnity added. It's unclear why they're tough to breed.

"For the first time, sperm was collected from a living salamander, cryopreserved, and brought back to life," said McGinnity, who is involved in the sperm-preservation effort with colleagues from Belgium's Antwerp Zoo and Michigan State University.

A sort of "insurance policy" against extinction, the sperm will enable scientists to manage hellbender breeding, according to team member Dalen Agnew, a reproductive pathologist at Michigan State University.

For instance, scientists can use the stored sperm to crossbreed individuals, he said, to ensure that wild hellbenders are genetically diverse, he said. Genetic diversity is important because if closely related salamanders breed, their inbred offspring will be weaker and more susceptible to disease.

Sperm-Filled Salamanders

Despite their hellish monikers, the "big, flaccid creatures" are actually "very mellow," Agnew said.

This docile nature certainly helps scientists collect salamander sperm, which is "milked" out of a hellbender by rubbing it between the front legs and tail, said Nashville Zoo's McGinnity.

Agnew also found that the hellbender sperm cell—like those of other amphibian species—boasts a ribbon of tissue encircling the tail. Magnified 40 times, it "almost looks like a corkscrew spinning," Agnew said.

The winding tissue likely adds a jolt of horsepower to the sperm cell, he said.
So far Agnew and colleagues—including Nashville Zoo's Sally Nofs and Michael Kirk and Antwerp Zoo's Robert Browne—used a unique "recipe" of preservation ingredients to keep hellbender sperm viable for six months—ideally, the sperm could be stored for hundreds of years.

Snot Otters Unchanged Since Dinosaur Days

Hellbenders haven't changed much since dinosaurs ruled the world, which puts the amphibians in nearly a class of their own, Nashville Zoo's McGinnity noted.

There are only two species related to the hellbender: the Chinese giant salamander (picture) and the Japanese giant salamander, which are also in decline. (Read about a new giant-salamander breeding center that opened in July in Washington, D.C.)

"If we lose them, we lose a lot of evolutionary history, as this group is unique and unlike anything else."

Is the Ice in the Arctic Ocean Getting Thinner?

The extent of the sea ice in the Arctic will reach its annual minimum in September. Forecasts indicate that it will not be as low as in 2007, the year of the smallest area covered by sea ice since satellites started recording such data. Nevertheless, sea ice physicists at the Alfred Wegener Institute are concerned about the long-term equilibrium in the Arctic Ocean.
They have indications that the mass of sea ice is dwindling because its thickness is declining. To substantiate this, they are currently measuring the ice thickness north and east of Greenland using the research aircraft Polar 5. The objective of the roughly one-week campaign is to determine the export of sea ice from the Arctic. Around a third to half of the freshwater export from the Arctic Ocean takes place in this way -- a major drive factor in the global ocean current system.

The question of when the Arctic will be ice-free in the summer has been preoccupying the sea ice researchers headed by Prof. Dr. Rüdiger Gerdes from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association for a long time now. Satellites have been recording the extent of the Arctic ice for more than 30 years. In addition to the area covered, the thickness of the ice is a decisive factor in assessing how much sea ice there is.

However, the thickness can only be determined locally, for example by means of the so-called EM-Bird, an electromagnetic measuring device which helicopters or planes tow over the ice. For Gerdes this is a very special job because he usually models his forecasts on his home computer. The campaign with the research aircraft Polar 5 of the Alfred Wegener Institute now takes him on an expedition in the Arctic for the first time. "I'm very keen on seeing the results of the sea ice thickness measurements," says Gerdes. "Only when we know the distribution of ice of varying thickness, can we calculate how much freshwater is carried out of the Arctic Ocean via ice."

About 3000 cubic kilometres of ice drift out of the Arctic Ocean every year, corresponding to around 2700 billion tons. The ice exports freshwater that reaches the Arctic Ocean via rivers and precipitation. This maintains its salt concentration, which has been constant over the long term. The temperature rise observed worldwide is especially pronounced in the Arctic latitudes. Researchers have been observing that the ice is getting thinner and thinner for several years now. As a result, it stores and exports less freshwater and the salt concentration (also referred to as salinity) of the Arctic Ocean declines.

On the one hand, this influences all living things that have adapted to the local conditions. On the other hand, changes in salinity also have an impact on current patterns of global ocean circulation and thus on meridional heat transport. In the TIFAX (Thick Ice Feeding Arctic Export) measurement campaign the researchers are primarily interested in ice that is several years old, several metres thick and occurs predominantly on the northern coast of Greenland. "Taking off on the measurement flights from Station Nord here is a special adventure," reports Gerdes from one of the northernmost measuring stations in the world. "Flying through virtually unsettled regions of the Arctic in the high-tech research aircraft is a stark contrast to my modelling work on the computer."

Nanoscale DNA Sequencing Could Spur Revolution in Personal Health Care

In experiments with potentially broad health care implications, a research team led by a University of Washington physicist has devised a method that works at a very small scale to sequence DNA quickly and relatively inexpensively.

That could open the door for more effective individualized medicine, for example providing blueprints of genetic predispositions for specific conditions and diseases such as cancer, diabetes or addiction.

"The hope is that in 10 years people will have all their DNA sequenced, and this will lead to personalized, predictive medicine," said Jens Gundlach, a UW physics professor and lead author of a paper describing the new technique published the week of Aug. 16 in the Proceedings of the National Academy of Sciences.

The technique creates a DNA reader that combines biology and nanotechnology using a nanopore taken from Mycobacterium smegmatis porin A. The nanopore has an opening 1 billionth of a meter in size, just large enough to measure a single strand of DNA as it passes through.

The scientists placed the pore in a membrane surrounded by potassium-chloride solution. A small voltage was applied to create an ion current flowing through the nanopore, and the current's electrical signature changed depending on the nucleotides traveling through the nanopore. Each of the nucleotides that are the essence of DNA -- cytosine, guanine, adenine and thymine -- produced a distinctive signature.

The team had to solve two major problems. One was to create a short and narrow opening just large enough to allow a single strand of DNA to pass through the nanopore and for only a single DNA molecule to be in the opening at any time. Michael Niederweis at the University of Alabama at Birmingham modified the M. smegmatis bacterium to produce a suitable pore.

The second problem, Gundlach said, was that the nucleotides flowed through the nanopore at a rate of one every millionth of a second, far too fast to sort out the signal from each DNA molecule. To compensate, the researchers attached a section of double-stranded DNA between each nucleotide they wanted to measure. The second strand would briefly catch on the edge of the nanopore, halting the flow of DNA long enough for the single nucleotide to be held within the nanopore DNA reader. After a few milliseconds, the double-stranded section would separate and the DNA flow continued until another double strand was encountered, allowing the next nucleotide to be read.

The delay, though measured in thousandths of a second, is long enough to read the electrical signals from the target nucleotides, Gundlach said.

"We can practically read the DNA sequence from an oscilloscope trace," he said.

Besides Gundlach and Niederweiss, other authors are Ian Derrington, Tom Butler, Elizabeth Manrao and Marcus Collins of the UW; and Mikhail Pavlenok at Alabama-Birmingham.

The work was funded by the National Institutes of Health and its National Human Genome Research Institute as part of a program to create technology to sequence a human genome for $1,000 or less. That program began in 2004, when it cost on the order of $10 million to sequence a human-sized genome.

The new research is a major step toward achieving DNA sequencing at a cost of $1,000 or less.

"Our experiments outline a novel and fundamentally very simple sequencing technology that we hope can now be expanded into a mechanized process," Gundlach said.

Ancient Galaxy Cluster Still Producing Stars

Much like quiet, middle-aged baby boomers peacefully residing in some of the world's largest cities, families of some galaxies also have a hidden wild youth that they only now are revealing for the first time, according to research by astronomers at Texas A&M University.
In ongoing observations of one of the universe's earliest, most distant cluster of galaxies using NASA's Spitzer Space Telescope, an international team of researchers led by Texas A&M's Dr. Kim-Vy Tran has discovered that a significant fraction of those ancient galaxies are still actively forming stars.

Tran, an assistant professor in the Texas A&M Department of Physics and Astronomy and member of the George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, and her team have spent the past four months analyzing images taken from the Multiband Imaging Photometer for Spitzer (MIPS), essentially looking back in time nearly 10 billion years at a high red-shift cluster known as CLG J02182-05102. Mere months after first discovering the cluster and the fact that it is shockingly "modern" in its appearance and size despite being observed just 4 billion years after the Big Bang, the Texas A&M-led team was able to determine that the galaxy cluster produces hundreds to thousands of new stars every year -- a far higher birthrate than what is present in nearby galaxies.

What is particularly striking, according to Tran, is the fact that the stellar birthrate is higher in the cluster's center than at the cluster's edges -- the exact opposite of what happens in our local portion of the universe, where the cores of galaxy clusters are known to be galactic graveyards full of massive elliptical galaxies composed of old stars.

"A well-established hallmark of galaxy evolution in action is how the fraction of star-forming galaxies decreases with increasing galaxy density," explains Tran, lead author of the team's study which appears in The Astrophysical Journal Letters. "In other words, there are more star-forming galaxies in the field than in the crowded cores of galaxy clusters. However, in our cluster, we find many galaxies with star-formation rates comparable to their cousins in the lower-density field environment."

Exactly why this star power increases as galaxies become more crowded remains a mystery. Tran thinks the densely-populated surroundings could lead to galaxies triggering activity in one another, or that all galaxies were extremely active when the universe was young.

The group's discovery holds potentially compelling implications that could ultimately reveal more about how such massive galaxies form. Observations of nearby galaxy clusters confirm that they are made of stars that are at least 8 to 10 billion years old, which means that CLG J02182-05102 is nearing the end of its hyperactive star-building period.

Now that they have pinpointed the epoch when galaxy clusters are making the last of their stars, astronomers can focus on understanding why massive assemblies of galaxies transition from very active to passive. Identifying how long it takes for galaxies in clusters to build up their stellar mass as well as the time at which they stop provides strong constraints for how these massive galaxies form.

"Our study shows that by looking farther into the distant universe, we have revealed the missing link between the active galaxies and the quiescent behemoths that live in the local universe," Tran adds. "Our discovery indicates that future studies of galaxy clusters in this red-shift range should be particularly fruitful for understanding how these massive galaxies form as a function of their environment."

Tran's team includes fellow Texas A&M astronomer Dr. Casey Papovich, who first identified the galaxy cluster CLG J02182-05102 in May. The collection of roughly 60 galaxies is observed just 4 billion years after the Big Bang, making it the earliest cluster of galaxies ever detected. However, the team was struck not by its age, but by its astoundingly modern appearance -- a huge, red collection of galaxies typical in only local clusters.

The fact that Tran's team was able to see these active galaxies so far back in time (Tran likens their find to discovering that her mild-mannered grandparent had lived a fast and furious youth) is only the preface to what they expect eventually to learn about these clusters. Tran will continue to lead an international collaboration with Papovich and their postdoctoral researchers to examine these clusters more thoroughly and hopefully to understand why they are still so energetic.

"We will analyze new observations scheduled to be taken with the Hubble Space Telescope and Herschel Space Telescope to study these galaxies more carefully to understand why they are so active," Tran adds. "We will also start looking at several more distant galaxy clusters to see if we find similar behavior."

DNA Puts Chemists on Scent of Better Artificial Nose

A new approach to building an "artificial nose" -- using fluorescent compounds and DNA -- could accelerate the use of sniffing sensors into the realm of mass production and widespread use, say Stanford chemists. If their method lives up to its promise, it could one day detect everything from incipiently souring milk to high explosives.
By sticking fluorescent compounds onto short strands of the molecules that form the backbone of DNA, the researchers have produced tiny sensor molecules that change color when they detect certain substances. The sensors were made using existing technology for synthesizing DNA, and are viewed with a fluorescence microscope.

The color changes enable the new sensors to convey far more information than most other existing optical sensors, which typically just detect one specific molecule, said Eric Kool, professor of chemistry and senior author of a paper published online this week in the German journal Angewandte Chemie.

"We were blown away by how strong the color changes were," Kool said. "One of the surprising findings was that we could tell the difference between four different organic vapors with just one sensor, because it would turn different colors with different vapors."

The key to Kool's versatile sensor molecules lies in the structure of DNA, the famous double helix that encodes the genetic blueprint for life, often described as looking like a twisted ladder. Two long parallel chains of sugar and phosphate molecules constitute the rails of the ladder, with the rungs made of pairs of molecules called bases. The arrangement of the bases, of which there are only four types, encodes the genetic data.

Kool's team of researchers developed a new set of fluorescent replacements for the DNA bases -- seven different ones they could choose from -- to attach to the DNA backbone of the new sensor in place of the usual four. They used only a single helix, so the bases project out from a single twisted pole, ready to detect organic vapors.

Florent Samain, a postdoctoral researcher in chemistry and lead author on the Angewandte Chemie paper, used DNA synthesis techniques to generate a library of all 2,401 possible ways that the seven substitute molecules could be combined in a string of four units.

The team then screened all the possible combinations for sensitivity to four different test substances -- as vapors -- that differed significantly in their structural and electronic properties.

One substance was commonly used as an aquatic herbicide, another as a solvent in research and industrial applications, another as an inhibitor of mold and bacteria in food and the fourth as an ingredient in products ranging from shoe polish to pesticides, as well as in the preparation of explosives.

The researchers found multiple sensors that showed marked fluorescent responses when exposed to the four test substances. "This is our first try with vapors and it ended up working really well," Kool said.

"What makes these sensors work exceptionally well is that the bases in DNA are stacked on one another, physically touching each other," he said. "DNA bases talk to one another, electronically."

That close physical contact also allows the compounds that Kool's group attaches to the DNA backbone to communicate with each other, which is crucial to their functionality.

What is also crucial, the researchers found out, is the order of the compounds along the DNA backbone. Like the sequence of natural DNA, which varies among different animals, the different sequences of the artificial DNA sensors gave different color changes.

"We saw a couple of examples where we had the same components, but in a different order and got a different response," Kool said. "So clearly they are talking to one another and whoever is next to someone else, it makes a difference."

"One of our long-term goals is to now build up a set of sensors for a much more complex range of possible substances for analysis," Kool said. "Because we get such a diversity of responses -- even one molecule can tell the difference among four different things -- we could have a set of 10 or 20, or 100 sensors, which would give a vast array of responses to many different kinds of molecules."

Having a large number of sensors available in a single device could broaden the application of the sensors from pure organic molecules such as the ones used in the tests to the many mixtures of molecules often encountered outside the laboratory.

Outside the lab is where the researchers see the DNA sensors being used most effectively. They hope to eventually pair their sensors with some type of portable device that would contain an inexpensive fluorescence microscope, which Kool says a number of other laboratories are already working on. One example -- called the "CellScope" -- was recently developed at the University of California-Berkeley.

The researchers still need to determine how small a quantity of any given substance the DNA sensors can detect.

"Another of our long-term goals is to print these sensors on plastic, and if the spots were big enough to see, you could see the color changes," Kool said. "You could hold a black light over the sensor and read the response. Then you could match up the color of the sensor with a key of some sort and say, 'Ah, this sensor best compares with this color on the key -- this milk is about to go sour.'"

Kool said it might even be possible, with more research, to use the DNA sensors in liquids.

"To me, the most intriguing possibility is smelling differences that are biologically important," Kool said. "It could be smelling differences in cells that are related to disease or sensing toxins in the environment. Those are probably the most likely applications in the near future.

"We want to sense everything," Kool said. "That is our ultimate goal."

Samantak Ghosh and Yin Nah Teo, both of whom recently graduated with PhD degrees in chemistry, also worked on the study and are coauthors of the paper in Angewandte Chemie. Kool is the George A. and Hilda M. Daubert Professor in Chemistry at Stanford.

Self-Cleaning Technology from Mars Can Keep Terrestrial Solar Panels Dust Free

Find dusting those tables and dressers a chore or a bore? Dread washing the windows? Imagine keeping dust and grime off objects spread out over an area of 25 to 50 football fields. That's the problem facing companies that deploy large-scale solar power installations, and scientists have now presented the development of one solution -- self-dusting solar panels ― based on technology developed for space missions to Mars.
In a report at the 240th National Meeting of the American Chemical Society (ACS) on August 22, they described how a self-cleaning coating on the surface of solar cells could increase the efficiency of producing electricity from sunlight and reduce maintenance costs for large-scale solar installations.

"We think our self-cleaning panels used in areas of high dust and particulate pollutant concentrations will highly benefit the systems' solar energy output," study leader Malay K. Mazumder, Ph.D. said. "Our technology can be used in both small- and large-scale photovoltaic systems. To our knowledge, this is the only technology for automatic dust cleaning that doesn't require water or mechanical movement."

Mazumder, who is with Boston University, said the need for that technology is growing with the popularity of solar energy. Use of solar, or photovoltaic, panels increased by 50 percent from 2003 to 2008, and forecasts suggest a growth rate of at least 25 percent annually into the future. Fostering the growth, he said, is emphasis on alternative energy sources and society-wide concerns about sustainability (using resources today in ways that do not jeopardize the ability of future generations to meet their needs).

Large-scale solar installations already exist in the United States, Spain, Germany, the Middle East, Australia, and India. These installations usually are located in sun-drenched desert areas where dry weather and winds sweep dust into the air and deposit it onto the surface of solar panel. Just like grime on a household window, that dust reduces the amount of light that can enter the business part of the solar panel, decreasing the amount of electricity produced. Clean water tends to be scarce in these areas, making it expensive to clean the solar panels.

"A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40 percent," Mazumder explains. "In Arizona, dust is deposited each month at about 4 times that amount. Deposition rates are even higher in the Middle East, Australia, and India."

Working with NASA, Mazumder and colleagues initially developed the self-cleaning solar panel technology for use in lunar and Mars missions. "Mars of course is a dusty and dry environment," Mazumder said, "and solar panels powering rovers and future manned and robotic missions must not succumb to dust deposition. But neither should the solar panels here on Earth."

The self-cleaning technology involves deposition of a transparent, electrically sensitive material deposited on glass or a transparent plastic sheet covering the panels. Sensors monitor dust levels on the surface of the panel and energize the material when dust concentration reaches a critical level. The electric charge sends a dust-repelling wave cascading over the surface of the material, lifting away the dust and transporting it off of the screen's edges.

Mazumder said that within two minutes, the process removes about 90 percent of the dust deposited on a solar panel and requires only a small amount of the electricity generated by the panel for cleaning operations.

The current market size for solar panels is about $24 billion, Mazumder said. "Less than 0.04 percent of global energy production is derived from solar panels, but if only four percent of the world's deserts were dedicated to solar power harvesting, our energy needs could be completely met worldwide. This self-cleaning technology can play an important role."

"Tiger" Tail

Image courtesy NASA

Caught between light and dark, a "tiger stripe" fissure on Saturn's moon Enceladus comes into stark relief in a picture taken by NASA's Cassini spacecraft during an August 13 flyby.

The tiger stripes near Enceladus's south pole are the sources of the moon's icy geysers, which spew water vapor and organic particles into space.

This particular fissure, dubbed Damascus Sulcus, was among several tiger stripes thermally scanned during a previous flyby (picture) as part of efforts to tell whether the geysers are produced by underground reservoirs of liquid water.

You Are There

Photograph courtesy NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

At a distance of 114 million miles (183 million kilometers), Earth and the moon appear as bright dots against a background of stars, as seen in a picture taken by NASA's MESSENGER spacecraft and released August 17.

MESSENGER is currently maneuvering toward a stable orbit around Mercury, the closest planet to the sun. Along the way, the probe has been searching for vulcanoids, small rocky objects theorized to exist in orbits between Mercury and the sun.

No vulcanoids have been detected so far, but MESSENGER will be the first NASA craft to orbit Mercury—putting it in a unique position to look for small, faint objects.

Published August 18, 2010

Titanic Is Falling Apart

Slipping beneath the waves on April 15, 1912, the R.M.S. Titanic famously disappeared from view until 1985, when it was rediscovered on the bottom of the North Atlantic (pictures of Titanic's rediscovery).

Now, scientists say, the legendary liner—beset by metal-eating life-forms, powerful currents, and possibly even human negligence—could be vanishing for good.

Titanic is falling apart.

Already explorers have documented caved-in roofs, weakening decks, a stern perhaps on the edge of collapse, and the disappearance of Titanic's crow's nest—from which lookout Frederick Fleet spotted history's most infamous iceberg.

"Everyone has their own opinion" as to how long Titanic will remain more or less intact, said research specialist Bill Lange of Woods Hole Oceanographic Institution in Massachusetts.

"Some people think the bow will collapse in a year or two," Lange said. "But others say it's going to be there for hundreds of years."

With Lange as optical-survey leader, a new expedition sets sail Sunday from St. John's, Newfoundland (map)—roughly 350 miles (560 kilometers) from the ship's 2.4-mile-deep (3.8-kilometer-deep) resting place (Titanic wreck-site map).

The goal: to virtually preserve Titanic in its current state and to finally determine just how far gone the shipwreck is, and how long it might last.

"We're trying to bring the actual hard data to the people who can make those determinations," Lange said.

Titanic Tech

The 20-day Expedition Titanic will use remotely operated submersibles to complete an unprecedented archaeological analysis of the two- by three-mile (three- by five-kilometer) debris field, including Titanic's two halves. The ship's bow and stern separated before sinking and now lie a third of a mile (half a kilometer) apart.

Thousands of high-resolution photos and video will be combined with acoustic and sonar mapping data to form a 3-D replica of the site, allowing scientists and armchair explorers to probe it in detail.

Some photos will reveal never before seen parts of Titanic, organizers say. Other images, when compared to evidence from earlier years, will help experts gauge the rate of the wreck's deterioration.

Expedition Titanic will gather hard data too, for example by measuring the thickness of the ship's hull and by hauling up and examining experimental steel platforms placed at the site.

In addition, scientists will take readings of the surrounding water to uncover its ability to support marine life—a prime cause of Titanic's deterioration.

Titanic Already Seen Crumbling

P.H. Nargeolet, co-leader of Expedition Titanic, made more than 30 submersible dives to the Titanic site in the 1980s and '90s—and saw it decline all the while.

Between 1987 and 1993, Nargeolet observed the gymnasium roof corroding and collapsing as well as the upper promenade deck deteriorating. On an early '90s dive he saw that the crow's nest—previously seen still attached to the forward mast—had disappeared altogether, apparently damaged to the point where it snapped off and fell to an as yet unidentified location

"In some places I saw a lot of difference, and in others almost nothing visible has happened," said Nargeolet, director of underwater research for RMS Titanic, Inc., a for-profit corporation that has retrieved Titanic artifacts for traveling exhibitions.

"For example, the stern section was the most destroyed part of the ship when it sank, and now most of the stern section is collapsed," he said. "The bow is pretty narrow and the strongest part of the ship, and it's still in relatively good condition."

What's Eating Titanic?

On the ocean floor, Titanic is at the mercy of several processes.

For one thing, the once 883-foot-long (270-meter-long) ship is a sprawling feast for marine organisms. Mollusks have consumed much of Titanic's wood—leaving the metal hull to microscopic bacteria and fungi.

As the microbes eat away at Titanic, they form self-contained, icicle-like biological communities called rusticles. By 1996 there were some 650 tons (dry weight) of rusticles on the outside of Titanic's bow section alone (picture), according to estimates by microbiologist Roy Cullimore, a veteran Titanic explorer. Since then rusticles have continued to grow both inside and outside the wreck.

Rusticles may also infest the interior of the forward mast, which as a result may completely collapse in the next year or two, according to Cullimore, founder of Regina, Canada-based Droycon Bioconcepts, Inc., a biotechnology company.

The upper promenade deck is also slowly crumbling, he said, and may implode within the next two decades at the current pace.

To build Titanic, Cullimore said, humans mined "iron from natural deposits and converted it into steel. Now the 'bugs' are ripping that steel apart, and some of that rusticle biomass is going back into pig iron"—crude, unrefined iron.

Much of the digested iron goes into the ocean environment, he noted, and eventually ends up in animals' bloodstreams or in sea plants that require iron for photosynthesis.

Even if rusticles weren't present, Titanic's hull might do a pretty good job of degrading on its own, in part because its mix of metals fosters a process called galvanic exchange.

Lead, bronze, brass, and other metals in Titanic are better than the iron that makes up most of the hull's steel at retaining their electrons.

When iron is connected to one of these other materials in an electrolyte, such as salt water, electrons flow from one metal to the next, causing iron to corrode quicker, according to the U.S. National Oceanic and Atmospheric Administration.

Currents, Humans Rub Titanic the Wrong Way?

The North Atlantic's surface was eerily calm the night Titanic sank, but strong and unpredictable currents at the seafloor are also taking a toll on the wreck.

"It's changing all the time," RMS Titanic, Inc.'s Nargeolet said of the current. "That pushing back and forth, back and forth is maybe like when a hurricane moves a tree for a few hours on one side and a few others on the other side. Finally the tree is gone.

"I could see a few holes on the deck a few years ago," he said. "Now these holes are getting really big—the current is going back and forth and working on them 24 hours a day."

Humans too may be hastening the ship's collapse—and have certainly altered its resting place.

Thousands of artifacts have been legally salvaged, for example, and an unknown number of others may have been illegally taken. Ships bearing scientists, filmmakers, and tourists have left modern trash behind.

What's more, ocean explorer Robert Ballard, who led the 1985 rediscovery of the ship, and others have suggested that submersibles might have caused considerable damage to Titanic by landing on or bumping into the ship—which Expedition Titanic will be careful not to do, according to project co-leader David Gallo.

The submersibles will explore around the ship but take all possible precautions not to damage it or become tangled with the wreckage—a danger for both Titanic and the expensive equipment, said Gallo, director of special projects at Woods Hole Oceanographic Institution.

"We're going to be very careful not to touch the ship," he said. "It's like any operation or exploratory surgery: There is always some risk, but we've done everything we can to ensure that we won't in any way alter the site itself."

Expedition Titanic may also uncover solid evidence as to which past damage may have been caused by humans—until now, most such evidence has been anecdotal, Gallo said. The survey will likely identify dive weights, cables, and other modern debris that might eventually be removed.

Hard Evidence of Titanic Decay

Expedition Titanic will retrieve hard evidence of corrosion at the Titanic site—steel test platforms that look something like mini-stepladders. First deployed in 1998, the platforms have endured the same destructive conditions as Titanic itself.

Because the scientists know precisely how thick the platforms were at deployment, they allow researchers to gauge exactly how fast metal degrades at the Titanic site. "Basically we look and see how much steel is left on them," Cullimore, the microbiologist, said.

The estimated rate of decay should allow scientists to better predict just how long Titanic will remain fairly intact.

Titanic Tomb Raiders?

In addition to Woods Hole Oceanographic Institution, several other top scientific organizations are managing the data collection. But RMS Titanic, Inc.—which holds exclusive salvage rights to the wreck—is funding the endeavor.

Titanic salvage has been a controversial issue for more than two decades, with Titanic discover Ballard among the critics.

According to Ballard, the Titanic site should remain undisturbed as a "sacred grave" for the more than 1,500 passengers and crew who died in the waters above. Instead, salvagers, tourists, and filmmakers have "turned her into a freak show at the county fair," he's said.

But Expedition Titanic organizers say they don't intend to raise any artifacts. "The only treasures we’re going to be looking for are treasures of the mind," project co-leader Gallo said. "And we’re not picking anything up but data."

Even so, the expedition's findings could add fuel to the salvage debate, Gallo admits.

"If we find out that the hull is going to collapse completely in the near term, what do we then think about the artifacts that are in that hull?" he said.

"Do we let it crumble naturally?" he asked. "Or do we try to somehow preserve the legacy by taking some of those pieces from the seafloor?"

Titanic: The Video Game?

When it comes to the controversial shipwreck, there's at least one thing everyone can agree on.

"I don't know of anyone that's said, Boy, the Titanic looks better than ever," Gallo said. "We know that it's deteriorating like most man-made things, which don't last long on the deep seafloor."

Expedition Titanic "is the first real attempt, in any rigorous sense, to get scientific evidence about what's happening to the ship and how fast it's happening," he added. "It's a systematic method of rigorous sampling and mapping."

Gallo hopes that the resulting 3-D archaeological model will be paired with immersive, video game-like technology that would allow people anywhere in the world to virtually explore the shipwreck for themselves.

Someday, of course, simulations will be all that's left of the legendary liner.

SpaceShipTwo Carrier Plane Damaged in Mojave

Disturbing news out of Mojave, Calif., this morning: The carrier aircraft for Virgin Galactic’s suborbital passenger spaceship was damaged yesterday when its left main landing gear collapsed on the runway.

The aircraft, known as WhiteKnightTwo, fortunately wasn’t carrying SpaceShipTwo, which has been undergoing test flights in Mojave for several months. WhiteKnightTwo was making its 37th flight when the gear collapsed.

In a brief statement, Scaled Composites of Mojave, Calif., which designed and manufactured SpaceShipTwo and WhiteKnightTwo, said on its website:

"A minor incident occurred on the runway at Mojave airport this morning, which involved a mechanical problem with the left hand-side landing gear of WhiteKnightTwo. No injuries were sustained and the incident did not involve the Spaceship, which was not attached to WhiteKnightTwo. WhiteKnightTwo was on its 37th test flight and has been flying since December 2008. Further information will be posted in due course."

WhiteKnightTwo and SpaceShipTwo are based on predecessor craft designed for a commercial spaceflight competition known as the Ansari X Prize. Scaled Composites, backed by Microsoft co-founder Paul Allen, won the $10 million prize in 2004 for a pair of suborbital spaceflights by a privately developed, reusable piloted craft.

Virgin Galactic’s Richard Branson hired Scaled Composites, now a subsidiary of Northrop Grumman, to build a fleet of spaceships for tourism and scientific research. Virgin, which is selling tickets to ride the spaceship for $200,000 a seat, has signed up about 350 people so far.

It is not yet known how the damage to WhiteKnightTwo will impact SpaceShipTwo's test program and pilot training.

(SpaceShipTwo, flying with a crew for the first time, is carried beneath WhiteKnightTwo during a July 15 test run. Credit: Virgin Galactic)