Tag: centers (page 2 of 4)

The (Not So) Curious Case of Galaxy IC 335

This odd-looking galaxy has recently become famous in the media, not for what it has but for what is missing!Excerpt from huffingtonpost.comA recent Hubble image of this galaxy shows it to be a star-filled galaxy with a flat shape not unlike our own M...

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Move Over Predator Alien: The human eye can see ‘invisible’ infrared light too

December 3, 2014 / Greg Giles / 0 Comments

The eye can detect light at wavelengths in the visual spectrum. Other wavelengths, such as infrared and ultraviolet, are supposed to be invisible to the human eye, but Washington University scientists have found that under certain conditions, it’s possible for us to see otherwise invisible infrared light. Image: Sara Dickherber

Excerpt from
news.wustl.edu
By Jim Dryden

Any science textbook will tell you we can’t see infrared light. Like X-rays and radio waves, infrared light waves are outside the visual spectrum.

But an international team of researchers co-led by scientists at Washington University School of Medicine in St. Louis has found that under certain conditions, the retina can sense infrared light after all.

Using cells from the retinas of mice and people, and powerful lasers that emit pulses of infrared light, the researchers found that when laser light pulses rapidly, light-sensing cells in the retina sometimes get a double hit of infrared energy. When that happens, the eye is able to detect light that falls outside the visible spectrum.

The findings are published Dec. 1 in the Proceedings of the National Academy of Sciences (PNAS) Online Early Edition. The research was initiated after scientists on the research team reported seeing occasional flashes of green light while working with an infrared laser. Unlike the laser pointers used in lecture halls or as toys, the powerful infrared laser the scientists worked with emits light waves thought to be invisible to the human eye.

“They were able to see the laser light, which was outside of the normal visible range, and we really wanted to figure out how they were able to sense light that was supposed to be invisible,” said Frans Vinberg, PhD, one of the study’s lead authors and a postdoctoral research associate in the Department of Ophthalmology and Visual Sciences at Washington University.

Vinberg, Kefalov and their colleagues examined the scientific literature and revisited reports of people seeing infrared light. They repeated previous experiments in which infrared light had been seen, and they analyzed such light from several lasers to see what they could learn about how and why it sometimes is visible.

“We experimented with laser pulses of different durations that delivered the same total number of photons, and we found that the shorter the pulse, the more likely it was a person could see it,” Vinberg explained. “Although the length of time between pulses was so short that it couldn’t be noticed by the naked eye, the existence of those pulses was very important in allowing people to see this invisible light.”

Robert Boston

Kefalov’s team developed this adapter that allowed scientists to analyze retinal cells and photopigment molecules as they were exposed to infrared light. The device already is commercially available and in use at several vision research centers around the world.

“The visible spectrum includes waves of light that are 400-720 nanometers long,” explained Kefalov, an associate professor of ophthalmology and visual sciences. “But if a pigment molecule in the retina is hit in rapid succession by a pair of photons that are 1,000 nanometers long, those light particles will deliver the same amount of energy as a single hit from a 500-nanometer photon, which is well within the visible spectrum. That’s how we are able to see it.”

Robert Boston

Frans Vinberg, PhD (left), and Vladimir J. Kefalov, PhD, sit in front of a tool they developed that allows them to detect light responses from retinal cells and photopigment molecules.

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Could orphan black hole confirm Einstein’s general theory of relativity?

November 21, 2014 / Greg Giles / 0 Comments

Excerpt from
csmonitor.com
By Pete Spotts

Scientists believe a mysteriously bright object in a galaxy 90 million light-years away could be a rogue black hole evicted during the merger of two galaxies.

Astronomers have long hunted for galaxies that might be evicting supermassive black holes at their centers. Eviction would represent an important confirmation of Einstein's theory of general relativity under extreme conditions and could help shed light on the influence such massive features have on the evolution of galaxies themselves.

Now they may have found one of those rogue black holes. A dwarf galaxy 90 million light-years from Earth hosts an unusually bright object some 2,600 light-years from its center – an object that carries many of the signatures one would expect from a supermassive black hole feasting on surrounding gas. The galaxy involved is known as Markarian 177, located within the constellation Big Dipper.

The object's position far from the center of the galaxy and the galaxy's odd shape makes it “the most promising candidate we've found” for a supermassive black hole ejected during the merger of two galaxies, says Laura Blecha, a researcher at the University of Maryland in College Park, who focuses on the interrelationship of supermassive black holes and their host galaxies as the two evolve. She cautions that a renegade black hole is not the only explanation for the object the team has observed.

If it is a supermassive black hole, however, it would represent a spectacular confirmation of Einstein's general theory of relativity as it relates to the enormous gravitational fields of supermassive black holes..

Black holes are objects so dense that their gravitational tug prevents even light from escaping. So-called stellar black holes form from the explosion and collapse of very massive stars.

Supermassive black holes tip the cosmic scales at millions to billions of times the mass of the sun. They are thought to lurk in the centers of most, if not all, galaxies. These behemoths are thought to play a key role in galaxy evolution by regulating a galaxy's rate of star formation.

When galaxies merge, so do their central black holes. Theorists have noted that based on Einstein's theory of general relativity, such black-hole mergers should generate powerful ripples in the very fabric of space-time, ripples known as gravitational waves. One way these merger-related gravity waves would make their presence known is through a recoil effect. This effect would be powerful enough to launch the single merged central black hole out of the center of its newly enlarged galaxy into an orbit that grows ever wider. If the galaxy's gravity was weak enough, as it might be in a dwarf galaxy, the black hole could travel fast enough to leave the galaxy altogether.

“Either way it's something very interesting,” she says.

Click to zoom

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Amazon, Google, IBM & Microsoft Want to Store Your Genome

November 7, 2014 / Greg Giles / 0 Comments

Excerpt from technologyreview.com

By Antonio Regalado

For $25 a year, Google will keep a copy of any genome in the cloud.

Google is approaching hospitals and universities with a new pitch. Have genomes? Store them with us.

The search giant’s first product for the DNA age is Google Genomics, a cloud computing service that it launched last March but went mostly unnoticed amid a barrage of high profile R&D announcements from Google...

Google Genomics could prove more significant than any of these moonshots. Connecting and comparing genomes by the thousands, and soon by the millions, is what’s going to propel medical discoveries for the next decade. The question of who will store the data is already a point of growing competition between Amazon, Google, IBM, and Microsoft.

Google began work on Google Genomics 18 months ago, meeting with scientists and building an interface, or API, that lets them move DNA data into its server farms and do experiments there using the same database technology that indexes the Web and tracks billions of Internet users.

This flow of data is smaller than what is routinely handled by large Internet companies (over two months, Broad will produce the equivalent of what gets uploaded to YouTube in one day) but it exceeds anything biologists have dealt with. That’s now prompting a wide effort to store and access data at central locations, often commercial ones. The National Cancer Institute said last month that it would pay $19 million to move copies of the 2.6 petabyte Cancer Genome Atlas into the cloud. Copies of the data, from several thousand cancer patients, will reside both at Google Genomics and in Amazon’s data centers.

The idea is to create “cancer genome clouds” where scientists can share information and quickly run virtual experiments as easily as a Web search, says Sheila Reynolds, a research scientist at the Institute for Systems Biology in Seattle. “Not everyone has the ability to download a petabyte of data, or has the computing power to work on it,” she says.

Also speeding the move of DNA data to the cloud has been a yearlong price war between Google and Amazon. Google says it now charges about $25 a year to store a genome, and more to do computations on it. Scientific raw data representing a single person’s genome is about 100 gigabytes in size, although a polished version of a person’s genetic code is far smaller, less than a gigabyte. That would cost only $0.25 cents a year.

The bigger point, he says, is that medicine will soon rely on a kind of global Internet-of-DNA which doctors will be able to search. “Our bird’s eye view is that if I were to get lung cancer in the future, doctors are going to sequence my genome and my tumor’s genome, and then query them against a database of 50 million other genomes,” he says. “The result will be ‘Hey, here’s the drug that will work best for you.’ ”

At Google, Glazer says he began working on Google Genomics as it became clear that biology was going to move from “artisanal to factory-scale data production.” He started by teaching himself genetics, taking an online class, Introduction to Biology, taught by Broad’s chief, Eric Lander. He also got his genome sequenced and put it on Google’s cloud.

Glazer wouldn’t say how large Google Genomics is or how many customers it has now, but at least 3,500 genomes from public projects are already stored on Google’s servers. He also says there’s no link, as of yet, between Google’s cloud and its more speculative efforts in health care, like the company Google started this year, called Calico, to investigate how to extend human lifespans. “What connects them is just a growing realization that technology can advance the state of the art in life sciences,” says Glazer.

Datta says some Stanford scientists have started using a Google database system, BigQuery, that Glazer’s team made compatible with genome data. It was developed to analyze large databases of spam, web documents, or of consumer purchases. But it can also quickly perform the very large experiments comparing thousands, or tens of thousands, of people’s genomes that researchers want to try. “Sometimes they want to do crazy things, and you need scale to do that,” says Datta. “It can handle the scale genetics can bring, so it’s the right technology for a new problem.”

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First legal pot, now Colorado launches new voting experiment

November 1, 2014 / Greg Giles / 0 Comments

Excerpt from nypost.com

As Colorado goes Election Night, so goes the nation — maybe.
The Centennial State is clearly a barometer of President Obama’s falling popularity.

The man who began his meteoric rise as the Democratic presidential nominee in Denver’s stadium in 2008 has lost much of his luster with Colorado voters and appears to be bringing down other Democrats with him.

Polls show Republican Cory Gardner ahead by seven points in his race to unseat incumbent Democratic Sen. Mark Udall, and GOP gubernatorial candidate Bob Beauprez is neck and neck with sitting Gov. John HIckenlooper.

But before Republicans pop the champagne corks, it’s worth considering the big wild card in this election.

Like the rest of Colorado’s roughly 3 million registered voters, I received my ballot in the mail about two weeks ago. This year will be the first that all Colorado voters received mail ballots, even without requesting them.

The potential for thousands more voters to cast ballots in what is usually a low-turnout midterm election could easily confound pollsters and politicos.

Conventional wisdom is that higher turnout favors Democrats — and the odds of higher turnout helping Dems in Colorado seem somewhat greater, given the demographics of the state.
Some 14 percent of eligible voters in Colorado are Hispanic. Obama improved his share of support among Colorado Hispanic voters from 61 percent in 2008 to 75 percent in 2012.

If mail ballots boost Hispanic voter participation by a few percentage points this year, it will likely redound to Democrats’ benefit. In a race as tight as the Colorado governor’s race, Hispanic voters could well determine the outcome.

But demographics don’t give the full picture. Since 2008, Democrats have benefited from a much stronger ground game that put operatives in the field to turn out their likely voters.

The effort wasn’t enough to stop populist Tea Party voters from boosting GOP fortunes in the 2010
congressional races, but Colorado was the exception. Democrat Michael Bennet won an open Senate race with just 30,000 more votes than his Republican opponent, Ken Buck.

The question in 2014 is whether mail balloting helps or erases the Democrats’ edge.

A New York Times analysis of Colorado mail ballots that had already been tallied 10 days out from the election seemed to give Republicans an advantage. Registered Republicans had mailed in ballots in higher numbers than Democrats, 42.8 percent to 32.3 percent.

But those trends may not continue. It could be that more Republicans simply cast their ballots early, which is where the Democratic ground game will come in handy.

Early voting makes it easier for “volunteers” — many of them paid political and union operatives — to go door to door to urge those who haven’t voted to do so.

Who is to stop “volunteers” from showing up with dozens of mail ballots collected from elderly voters or others who may have been pressured by union reps or family members to cast their votes?
Colorado will have regulations in place to limit the number of ballots a single individual can drop off at collection centers after 2015, but this year the possibility of ballot stuffing is real.

State election officials claim that the signature on the ballot envelope is their way to detect phony ballots. But the system hardly seems foolproof, requiring signatures to be scanned and matched against a database that may prove more cumbersome than anticipated.

Nov. 4 will be a test for Colorado — and for the nation — on this new experiment in democracy.

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7 Types of Non-Believers Who Don’t Need Religion

September 25, 2014 / Steven Lanier's Journey - Main Article Directory / 0 Comments

Valerie Tarico, AlterNetReligious labels help shore up identity. So what are some of the things non-believers can call themselves?Catholic, born-again, Reformed, Jew, Muslim, Shiite, Sunni, Hindu, Sikh, Buddhist…religions give people labels. The downside can be tribalism, an assumption that insiders are better than outsiders, that they merit more compassion, integrity and generosity or even that violence toward “infidels” is acceptable. But the upside is that religious o [...]

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War Is Destroying Syria’s Ancient Treasures, Satellite Photos Show

September 20, 2014 / Greg Giles / 0 Comments

Satellite images show how much destruction has happened in Syria between December 2011 and July 2014. The Ministry of Justice building (red arrow) is damaged, as is the Khusriwiye Mosque (green arrow).

Excerpt from news.yahoo.com
By Laura Geggel, Staff Writer

Three years of heavy fighting have taken a toll on Syria's archaeological treasures. Five of the country's six World Heritage sites "exhibit significant damage," and some buildings are now "reduced to rubble," according to high-resolution satellite images examined by the nonprofit and nonpartisan American Association for the Advancement of Science (AAAS).

"Only one of Syria's six World Heritage sites — the ancient city of Damascus — appears to remain undamaged in satellite imagery since the onset of civil war in 2011," Susan Wolfinbarger, director of the Geospatial Technologies and Human Rights Project at AAAS, said in a statement.

Damage to the other five sites is extensive, the AAAS said. These sites include the ancient city of Aleppo, the ancient city of Bosra, the ancient site of Palmyra, a site with two castles (Crac des Chevaliers and Qal'at Salah El-Din), and the ancient villages of northern Syria (Jebel Seman, Jebel Barisha, Jebel Al A'la, Jebel Wastani and Jebel Zawiye.

The analysis showed widespread damage in Aleppo, one of the oldest continuously occupied cities in the world, which dates back to the second millennium B.C.

A before-and-after analysis from 2011 to 2014 indicates new damage to historic mosques, Koranic schools called madrasas, the Great Mosque of Aleppo, the Souq al-Madina, the Grand Serail of Aleppo, the Hammam Yalbougha an-Nasry, the Khusruwiye Mosque, the Carlton Citadel Hotel, the Khan Qurt Bey caravanserai and other historic buildings south and north of the citadel.

The Great Mosque has extensive damage. Satellite imagery showed destruction of the roof and a destroyed minaret, or tall spire, as well as two craters on the mosque's eastern wall. Researchers saw the heaviest damage south of the citadel, but the area to the north, which has buildings from the late Mamluk to Ottoman periods (13th to 19th centuries) also showed signs of destruction.

The other World Heritage sites have damage ranging from mortar impacts near an ancient Roman theater in Bosra to newly constructed military compounds on an archaeological site. New roads and mounds of earth are scattered through the Northern Roman Necropolis in Palmyra.

Palmyra sits in a desert just northeast of Damascus. Its ruins combine Greco-Roman art with Persian influences, and UNESCO said it "contains the monumental ruins of a great city that was one of the most important cultural centers of the ancient world."

The AAAS released the analysis yesterday (Sept. 18), a day before the Smithsonian Institution's meeting to honor the 1954 Hague Convention for the Protection of Cultural Property. Researchers plan to discuss the damage and intervention efforts in Syria at the meeting.

"There is hope, and it lies with our Syrian colleagues because they are the stewards and caretakers of these sites, and they see the value in preserving and protecting them for future generations," said Corine Wegener, cultural heritage preservation officer for the Smithsonian Institution. "What they need from their international colleagues is some help to do that — training, materials and other support in the international arena for the notion that it is possible to mitigate and prevent damage to cultural heritage, even in the midst of conflicts."

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So what is a supermassive black hole anyway?

September 19, 2014 / Greg Giles / 0 Comments

Artist's rendering of a black hole recently discovered in the ultracompact dwarf galaxy M60-UCD1.

csmonitor.com

The discovery of a supermassive black hole inside a tiny dwarf galaxy has shed new light on the potential number of black holes in the universe.

An international team of researchers has discovered a supermassive black hole in M60-UCD1, a dwarf galaxy some 54-million light years away. M60-UCD1 is about 500 times smaller than our own galaxy, the Milky Way, and 1,000 times less massive. The researchers published their findings Wednesday in Nature.

Scientists have previously identified numerous supermassive black holes throughout the universe – including one at the center of the Milky Way. But this is the first time that any of these largest types of black holes have been found in such a small galaxy, says study lead author Anil Seth, an assistant professor of physics and astronomy University of Utah in Salt Lake City.

The revelation that a supermassive black hole can exist within an ultracompact dwarf galaxy could mean that there might be twice as many of these largest black holes than astronomers previously thought.

Black holes come in several different varieties, all of which are characterized by a dense concentration of mass compressed into a tiny space and a gravitational force so powerful it keeps light from escaping.

The smallest kind, called a primordial black hole, is the size of a single atom, but it contains the mass of a large mountain. The most widely understood black holes are known as stellar black holes and can contain 20 times the mass of the sun within a ball of space with a diameter of about 10 miles. Supermassive black holes can be as vast as the entire solar system and contain as much mass as found in 1 million suns combined.

Primordial black holes are believed to have formed during the early evolution of the universe, shortly after the Big Bang. Stellar black holes are thought to be the result of the collapse of a massive star. The formation of supermassive black holes has so far remained something of a mystery.

“We know supermassive black holes exist in the center of most big galaxies … but we actually don’t know how they’re formed,” says Dr. Seth. “We just know they formed a long time ago.”

Black holes are difficult to study because their tendency to pull light inside their centers renders them effectively invisible.

Telescopes can observe contextual clues that suggest the presence of a black hole, such as stars orbiting around an apparent void.

“We can actually see stars moving around the center of the supermassive black hole of our galaxy,” Seth says. “It is much more difficult to study smaller galaxies.”

This particular dwarf galaxy happens to have so many stars – and a black hole that is so large – that telltale signs of the black hole were detected by two telescopes, the optical/infrared Gemini North telescope atop Hawaii’s Mauna Kea and the Hubble Space Telescope.

Typically, the size of a black hole is directly proportional to the size of the galaxy. Seth suspects that M60-UCD1 is actually the remains of a much larger galaxy.

“We think that this thing is a galaxy where the outer part of the galaxy has been stripped away by an interaction with another bigger galaxy and that the core has been left behind,” Seth explains.

In general, however, current technology has not yet reached a point that enables astronomers to definitively identify the presence of black holes in smaller galaxies.

By studying this and other black holes, scientists hope to unravel some of the mysteries of the origins of the universe.

“It turns out that black holes actually play a pretty big role in how galaxies form,” Seth says. “To understand our origin story we need to understand the formation of galaxies. And black holes, even though they are just a tiny fraction of all the mass in the galaxy, can play a really important role in their evolution."

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Space station detector reports more hints of dark matter—or not

September 19, 2014 / Greg Giles / 0 Comments

Adrian Cho

New reports of further evidence for dark matter have been greatly exaggerated. Yesterday, researchers working with the Alpha Magnetic Spectrometer (AMS), a $2 billion cosmic ray detector attached to the International Space Station, reported their latest data on a supposed excess of high-energy positrons from space. They contended—at least in a press release—that the new results could offer new hints that they’ve detected particles of dark matter, the mysterious stuff whose gravity binds the galaxies. But several cosmic ray physicists say that the AMS data are still perfectly consistent with much more mundane explanations of the excess. And they doubt AMS alone will resolve the issue.
The leader of the AMS team, Nobel laureate Samuel Ting of the Massachusetts Institute of Technology in Cambridge, takes care to say that the new results do not prove that AMS has detected dark matter. But he also says the data lend more support to that interpretation than to some others. "The key statement is that we have not found a contradiction with the dark matter explanation," he says.
The controversy centers on AMS's measurement of a key ratio, the number of antimatter positrons to the sum of positrons and electrons. In April 2013, AMS confirmed early reports that as the energy of the particles increased above about 8 gigaelectron Volts (GeV), that ratio, or "positron fraction," increased, even as the individual fluxes of electrons and positrons were falling. That increase in the relative abundance of positrons could signal the presence of dark matter particles. According to many theories, if those particles collide, they would annihilate each other to produce electron-positron pairs. That would alter the balance of electrons and positrons among cosmic rays, as the usual source such as the cloudlike remnants of supernova explosions produce far more electrons than positrons.
However, that interpretation was hardly certain. Even before AMS released its measurement of the ratio, astrophysicists had argued that the excess positrons could potentially emanate from an undetected nearby pulsar. In November 2013, Eli Waxman, a theoretical astrophysicist at the Weizmann Institute of Science in Rehovot, Israel, and colleagues went even further. They argued that the excess positrons could come simply from the interactions of "primary" cosmic rays from supernova remnants with the interstellar medium. If so, then the positrons were just "secondary" rays and nothing to write home about.
However, AMS team researchers see two new features that are consistent with the dark matter interpretation, they reported online yesterday in Physical Review Letters. First, the AMS team now sees that after rising with energy, the positron fraction seems to level off and may begin to fall at an energy of 275 GeV, as would be expected if the excess were produced by colliding dark matter particles, as the original particles' mass would put an upper limit on the energy of the positron they spawned. AMS researchers say the leveling off would be consistent with a dark matter particle with a mass of 1 teraelectron volt (TeV). (Thanks to Albert Einstein’s famous equivalence of mass and energy, the two can be measured in the same units.)
Second, the AMS team measured the spectra of electrons and positrons individually. They found that the spectra have different shapes as energy increases. "It's really surprising that the electrons and positrons are so different," Ting says. And, he argues, the difference suggests that the positrons cannot be secondary cosmic rays produced by primary cosmic ray electrons, as such production should lead to similar spectra.
But some cosmic ray physicists aren't convinced. For example, in AMS's graph of the electron fraction, the error bars at the highest energies are large because the high-energy particles are so rare. And those uncertainties make it unclear whether the positron fraction really starts to drop, says Stéphane Coutu, a cosmic ray physicist at Pennsylvania State University, University Park. And even if the positron fraction does fall at energies higher than AMS reported, that wouldn't prove the positrons come from dark matter annihilations, Coutu says. Such a "cutoff" could easily arise in positrons from a pulsar, he says, if the spatial region in which the pulsar accelerates particles is of limited size. All told, the new results are "probably consistent with anything," Coutu says.
Similarly, Waxman questions Ting's claim that the new data suggest the positrons aren't simply secondary cosmic rays. If that were the case, then the electrons and positrons would be coming from different places and there would be no reason to expect their spectra to be similar, Waxman says. Moreover, he notes, AMS's measurement of the positron fraction seems to level out just at the limit that he and colleagues predicted would be the maximum achievable through secondary cosmic rays. So, in fact, the new data support the interpretation that the positrons are simply secondary cosmic rays, he says. "To me this is a very strong indication that we are seeing cosmic ray interactions.”
Will the argument ever end? AMS is scheduled to take data for 10 more years, which should enable scientists to whittle down the uncertainties and extend their reach toward higher energies, Ting says. "I think we should be able to reach 1 TeV with good statistics," he says, and that should be enough to eventually settle the dispute. But Gregory Tarlé, an astrophysicist at the University of Michigan, Ann Arbor, says, "I don't think that's a legitimate claim." Higher energy cosmic rays arrive at such a low rate that even quadrupling the data set would leave large statistical uncertainties, he says. So, Tarlé suspects, years from now the AMS results will likely look about as ambiguous they do now.

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