Tag: spectrum (page 2 of 5)

Chances of Exoplanet Life ‘Impossible’? Or ‘100 percent’?

March 9, 2015 / / 0 Comments


Kepler’s Exoplanets: A map of the locations of exoplanets, of various masses, in the Kepler field of view. 1,235 candidates are plotted (NASA/Wendy Stenzel)


 news.discovery.com 

Just in case you haven’t heard, our galaxy appears to be teeming with small worlds, many of which are Earth-sized candidate exoplanets and dozens appear to be orbiting their parent stars in their “habitable zones.”

Before Wednesday’s Kepler announcement, we knew of just over 500 exoplanets orbiting stars in the Milky Way. Now the space telescope has added another 1,235 candidates to the tally — what a difference 24 hours makes.

Although this is very exciting, the key thing to remember is that we are talking about exoplanet candidates, which means Kepler has detected 1,235 exoplanet signals, but more work needs to be done (i.e. more observing time) to refine their orbits, masses and, critically, to find out whether they actually exist.

But, statistically speaking, a pattern is forming. Kepler has opened our eyes to the fact our galaxy is brimming with small worlds — some candidates approaching Mars-sized dimensions!

Earth-Brand™ Life

Before Kepler, plenty of Jupiter-sized worlds could be seen, but with its precision eye for spotting the tiniest of fluctuations of star brightness (as a small exoplanet passes between Kepler and the star), the space telescope has found that smaller exoplanets outnumber the larger gas giants.

Needless to say, all this talk of “Earth-sized” worlds (and the much-hyped “Earth-like” misnomer) has added fuel to the extraterrestrial life question: If there’s a preponderance of small exoplanets — some of which orbit within the “sweet-spot” of the habitable zones of their parent stars — could life as we know it (or Earth-Brand™ Life as I like to call it) also be thriving there?
Before I answer that question, let’s turn back the clock to Sept. 29, 2010, when, in the wake of the discovery of the exoplanet Gliese 581 g, Steven Vogt, professor of astronomy and astrophysics at University of California Santa Cruz, told Discovery News: “Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say that the chances for life on [Gliese 581 g] are 100 percent. I have almost no doubt about it.”

Impossible? Or 100 Percent?

As it turns out, Gliese 581 g may not actually exist — an excellent example of the progress of science scrutinizing a candidate exoplanet in complex data sets as my Discovery News colleague Nicole Gugliucci discusses in “Gliese 581g and the Nature of Science” — but why was Vogt so certain that there was life on Gliese 581 g? Was he “wrong” to air this opinion?

Going to the opposite end of the spectrum, Howard Smith, an astrophysicist at Harvard University, made the headlines earlier this year when he announced, rather pessimistically, that aliens will unlikely exist on the extrasolar planets we are currently detecting.
“We have found that most other planets and solar systems are wildly different from our own. They are very hostile to life as we know it,” Smith told the UK’s Telegraph.

Smith made comparisons between our own solar system with the interesting HD 10180 system, located 127 light-years away. HD 10180 was famous for a short time as being the biggest star system beyond our own, containing five exoplanets (it has since been trumped by Kepler-11, a star system containing six exoplanets as showcased in Wednesday’s Kepler announcement).

One of HD 10180′s worlds is thought to be around 1.4 Earth-masses, making it the smallest detected exoplanet before yesterday. Alas, as Smith notes, that is where the similarities end; the “Earth-sized” world orbiting HD 10180 is too close to its star, meaning it is a roasted exoplanet where any atmosphere is blasted into space by the star’s powerful radiation and stellar winds.
The Harvard scientist even dismissed the future Kepler announcement, pointing out that upcoming reports of habitable exoplanets would be few and far between. “Extrasolar systems are far more diverse than we expected, and that means very few are likely to support life,” he said.

Both Right and Wrong

So what can we learn about the disparity between Vogt and Smith’s opinions about the potential for life on exoplanets, regardless of how “Earth-like” they may seem?

Critically, both points of view concern Earth-Brand™ Life (i.e. us and the life we know and understand). As we have no experience of any other kind of life (although the recent eruption of interest over arsenic-based life is hotly debated), it is only Earth-like life we can realistically discuss.

We could do a Stephen Hawking and say that all kinds of life is possible anywhere in the cosmos, but this is pure speculation. Science only has life on Earth to work with, so (practically speaking) it’s pointless to say a strange kind of alien lifeform could live on an exoplanet where the surface is molten rock and constantly bathed in extreme stellar radiation.

If we take Hawking’s word for it, Vogt was completely justified for being so certain about life existing on Gliese 581 g. What’s more, there’s no way we could prove he’s wrong!

But if you set the very tight limits on where we could find Earth-like life, we are suddenly left with very few exoplanet candidates that fit the bill. Also, just because an Earth-sized planet might be found in the habitable zone of its star, doesn’t mean it’s actually habitable. There are many more factors to consider. So, in this case, Smith’s pessimism is well placed.

Regardless, exoplanet science is in its infancy and the uncertainty with the “is there life?” question is a symptom of being on the “raggedy edge of science,” as Nicole would say. We simply do not know what it takes to make a world habitable for any kind of life (apart from Earth), but it is all too tempting to speculate as to whether a race of extraterrestrials, living on one of Kepler’s worlds, is pondering these same questions.

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Monster Black Hole Is the Largest and Brightest Ever Found

February 25, 2015 / / 0 Comments



Largest and Brightest Black Hole
An artist's illustration of a monster supermassive black hole at the heart of a quasar in the distant universe. Scientists say the newfound black hole SDSS J010013.02+280225.8 is the largest and brightest ever found.

Excerpt from space.com

 Astronomers have discovered the largest and most luminous black hole ever seen — an ancient monster with a mass about 12 billion times that of the sun — that dates back to when the universe was less than 1 billion years old.

It remains a mystery how black holes could have grown so huge in such a relatively brief time after the dawn of the universe, researchers say.

Supermassive black holes are thought to lurk in the hearts of most, if not all, large galaxies. The largest black holes found so far in the nearby universe have masses more than 10 billion times that of the sun. In comparison, the black hole at the center of the Milky Way is thought to have a mass only 4 million to 5 million times that of the sun. 


Although not even light can escape the powerful gravitational pulls of black holes — hence, their name — black holes are often bright. That's because they're surrounded by features known as accretion disks, which are made up of gas and dust that heat up and give off light as it swirl into the black holes. Astronomers suspect that quasars, the brightest objects in the universe, contain supermassive black holes that release extraordinarily large amounts of light as they rip apart stars.
So far, astronomers have discovered 40 quasars — each with a black hole about 1 billion times the mass of the sun — dating back to when the universe was less than 1 billion years old. Now, scientists report the discovery of a supermassive black hole 12 billion times the mass of the sun about 12.8 billion light-years from Earth that dates back to when the universe was only about 875 million years old.

This black hole — technically known as SDSS J010013.02+280225.8, or J0100+2802 for short — is not only the most massive quasar ever seen in the early universe but also the most luminous. It is about 429 trillion times brighter than the sun and seven times brighter than the most distant quasar known.

The light from very distant quasars can take billions of years to reach Earth. As such, astronomers can see quasars as they were when the universe was young.

This black hole dates back to a little more than 6 percent of the universe's current age of 13.8 billion years.

"This is quite surprising because it presents serious challenges to theories of black hole growth in the early universe," said lead study author Xue-Bing Wu, an astrophysicist at Peking University in Beijing.

Accretion discs limit the speed of modern black holes' growth. First, as gas and dust in the disks get close to black holes, traffic jams slow down any other material that's falling into them. Second, as matter collides in these traffic jams, it heats up, emitting radiation that drives gas and dust away from the black holes.

Newfound Quasar SDSS J0100+2802
The newfound quasar SDSS J0100+2802 has the most massive black hole and the highest luminosity among all known distant quasars, as shown in this comparison chart of the black hole's mass and brightness.


Scientists still do not have a satisfactory theory to explain how these supermassive objects formed in the early universe, Wu said.

"It requires either very special ways to quickly grow the black hole or a huge seed black hole," Wu told Space.com. For instance, a recent study suggested that because the early universe was much smaller than it is today, gas was often denser, obscuring a substantial amount of the radiation given off by accretion disks and thus helping matter fall into black holes.

The researchers noted that the light from this black hole could help provide clues about the dark corners of the distant cosmos. As the quasar's light shines toward Earth, it passes through intergalactic gas that colors the light. By deducing how this intergalactic gas influenced the spectrum of light from the quasar, scientists can deduce which elements make up this gas. This knowledge, in turn, can provide insight into the star-formation processes that were at work shortly after the Big Bang that produced these elements.

"This quasar is the most luminous one in the early universe, which, like a lighthouse, will provide us chances to use it as a unique tool to study the cosmic structure of the dark, distant universe," Wu said.
The scientists detailed their findings in the Feb. 26 issue of the journal Nature.

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Cluster Filled with Dark Matter May House ‘Failed Galaxies’

February 21, 2015 / / 0 Comments

The Coma Cluster


Excerpt space.com

 A strange set of 48 galaxies appears to be rich in dark matter and lacking in stars, suggesting that they may be so-called "failed" galaxies, a new study reports.

The galaxies in question are part of the Coma Cluster, which lies 300 million light-years from Earth and packs several thousand galaxies into a space just 20 million light-years across. To study them, Pieter van Dokkum of Yale University and his colleagues used the Dragonfly Telephoto Array in New Mexico.

The array's eight connected Canon telephoto lenses allow the researchers to search for extremely faint objects that traditional telescope surveys miss. Often, such as when the researchers used the array to search for the faint glow that dark matter might create, the hunt comes up empty. 


But when van Dokkum and his colleagues looked toward the Coma Cluster, they found a pleasant surprise.

"We noticed all these faint little smudges in the images from the Dragonfly telescope," van Dokkum told Space.com.

The mysterious blobs nagged at van Dokkum, compelling him to look into the objects further. Fortuitously, NASA's Hubble Space Telescope had recently captured one of these objects with its sharp eye. 

"It turned out that they're these fuzzy blobs that look somewhat like dwarf spheroidal galaxies around our own Milky Way," van Dokkum said. "So they looked familiar in some sense … except that if they are at the distance of the Coma Cluster, they must be really huge."

And with very few stars to account for the mass in these galaxies, they must contain huge amounts of dark matter, the researchers said. In fact, to stay intact, the 48 galaxies must contain 98 percent dark matter and just 2 percent "normal" matter that we can see. The fraction of dark matter in the universe as a whole is thought to be around 83 percent. 

But before making this claim, the team had to verify that these blobs really are as distant as the Coma Cluster. (In fact, the team initially thought the galaxies were much closer.). But even in the Hubble image the stars were not resolved. If Hubble — one of the most powerful telescopes in existence — can't resolve the stars, those pinpricks of light must be pretty far away, study team members reasoned. 

Now, van Dokkum and his colleagues have definitive evidence: They've determined the exact distance to one of the galaxies. The team used the Keck Telescope in Hawaii to look at one of the objects for two hours. This gave them a hazy spectrum, from which they were able to tease out the galaxy's recessional velocity — that is, how fast it is moving away from Earth.

That measure traces back to the Hubble Telescope's namesake. In 1929, American astronomer Edwin Hubble discovered one of the simplest and most surprising relationships in astronomy: The more distant a galaxy, the faster it moves away from the Milky Way.

Today, astronomers use the relationship to measure a galaxy's recessional velocity and thus calculate the galaxy's distance. In this case, the small fuzzy blob observed with Keck was moving away from Earth at 15.7 million mph (25.3 million km/h). That places it at 300 million light-years away from Earth, the distance of the Coma Cluster.

So the verdict is officially in: These galaxies must be associated with the Coma Cluster and therefore must be extremely massive.
"It looks like the universe is able to make unexpected galaxies," van Dokkum said, adding that there is an amazing diversity of massive galaxies.

But the clusters still present a mystery: The team doesn't know why they have so much dark matter and so few stars.

Though they look serene and silent from our vantage on Earth, stars are actually roiling balls of violent plasma. Test your stellar smarts with this quiz.
One possibility is that these are "failed" galaxies. A galaxy's first supernova explosions will drive away huge amounts of gas. 

Normally, the galaxy has such a strong gravitational pull that most of the expelled gas falls back onto the galaxy and forms the next generations of stars. But maybe the strong gravitational pull of the other galaxies in the Coma Cluster interfered with this process, pulling the gas away.

"If that happened, they had no more fuel for star formation and they were sort of stillborn galaxies where they started to get going but then failed to really build up a lot of stars," said van Dokkum, adding that this is the most likely scenario. 

Another possibility is that these galaxies are in the process of being ripped apart. But astronomers expect that if this were the case, the galaxies would be distorted and streams of stars would be flowing away from them. Because these effects don't appear, this scenario is very unlikely.

The next step is to try to measure the individual motions of stars within the galaxies. If the team knew those stars' speeds, it could calculate the galaxies' exact mass, and therefore the amount of dark matter they contain. If the stars move faster, the galaxy is more massive. And if they move slower, the galaxy is less massive. 
However, this would require a better spectrum than the one the team has right now.

"But it's not outside the realm of what's possible," van Dokkum assured. "It's just very hard."

The original study has been published in Astrophysical Journal Letters. You can read it for free on the preprint site arXiv.org.

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Why science is so hard to believe?

February 19, 2015 / / 0 Comments

 
In the recent movie “Interstellar,” set in a futuristic, downtrodden America where NASA has been forced into hiding, school textbooks say the Apollo moon landings were faked.


Excerpt from 


There’s a scene in Stanley Kubrick’s comic masterpiece “Dr. Strangelove” in which Jack D. Ripper, an American general who’s gone rogue and ordered a nuclear attack on the Soviet Union, unspools his paranoid worldview — and the explanation for why he drinks “only distilled water, or rainwater, and only pure grain alcohol” — to Lionel Mandrake, a dizzy-with-anxiety group captain in the Royal Air Force.
Ripper: “Have you ever heard of a thing called fluoridation? Fluoridation of water?”
Mandrake: “Ah, yes, I have heard of that, Jack. Yes, yes.”Ripper: “Well, do you know what it is?”
Mandrake: “No. No, I don’t know what it is, no.”
Ripper: “Do you realize that fluoridation is the most monstrously conceived and dangerous communist plot we have ever had to face?” 

The movie came out in 1964, by which time the health benefits of fluoridation had been thoroughly established and anti-fluoridation conspiracy theories could be the stuff of comedy. Yet half a century later, fluoridation continues to incite fear and paranoia. In 2013, citizens in Portland, Ore., one of only a few major American cities that don’t fluoridate, blocked a plan by local officials to do so. Opponents didn’t like the idea of the government adding “chemicals” to their water. They claimed that fluoride could be harmful to human health.

Actually fluoride is a natural mineral that, in the weak concentrations used in public drinking-water systems, hardens tooth enamel and prevents tooth decay — a cheap and safe way to improve dental health for everyone, rich or poor, conscientious brushers or not. That’s the scientific and medical consensus.
To which some people in Portland, echoing anti-fluoridation activists around the world, reply: We don’t believe you.
We live in an age when all manner of scientific knowledge — from the safety of fluoride and vaccines to the reality of climate change — faces organized and often furious opposition. Empowered by their own sources of information and their own interpretations of research, doubters have declared war on the consensus of experts. There are so many of these controversies these days, you’d think a diabolical agency had put something in the water to make people argumentative.
Science doubt has become a pop-culture meme. In the recent movie “Interstellar,” set in a futuristic, downtrodden America where NASA has been forced into hiding, school textbooks say the Apollo moon landings were faked.


The debate about mandated vaccinations has the political world talking. A spike in measles cases nationwide has President Obama, lawmakers and even potential 2016 candidates weighing in on the vaccine controversy. (Pamela Kirkland/The Washington Post)
In a sense this is not surprising. Our lives are permeated by science and technology as never before. For many of us this new world is wondrous, comfortable and rich in rewards — but also more complicated and sometimes unnerving. We now face risks we can’t easily analyze.
We’re asked to accept, for example, that it’s safe to eat food containing genetically modified organisms (GMOs) because, the experts point out, there’s no evidence that it isn’t and no reason to believe that altering genes precisely in a lab is more dangerous than altering them wholesale through traditional breeding. But to some people, the very idea of transferring genes between species conjures up mad scientists running amok — and so, two centuries after Mary Shelley wrote “Frankenstein,” they talk about Frankenfood.
The world crackles with real and imaginary hazards, and distinguishing the former from the latter isn’t easy. Should we be afraid that the Ebola virus, which is spread only by direct contact with bodily fluids, will mutate into an airborne super-plague? The scientific consensus says that’s extremely unlikely: No virus has ever been observed to completely change its mode of transmission in humans, and there’s zero evidence that the latest strain of Ebola is any different. But Google “airborne Ebola” and you’ll enter a dystopia where this virus has almost supernatural powers, including the power to kill us all.
In this bewildering world we have to decide what to believe and how to act on that. In principle, that’s what science is for. “Science is not a body of facts,” says geophysicist Marcia McNutt, who once headed the U.S. Geological Survey and is now editor of Science, the prestigious journal. “Science is a method for deciding whether what we choose to believe has a basis in the laws of nature or not.”
The scientific method leads us to truths that are less than self-evident, often mind-blowing and sometimes hard to swallow. In the early 17th century, when Galileo claimed that the Earth spins on its axis and orbits the sun, he wasn’t just rejecting church doctrine. He was asking people to believe something that defied common sense — because it sure looks like the sun’s going around the Earth, and you can’t feel the Earth spinning. Galileo was put on trial and forced to recant. Two centuries later, Charles Darwin escaped that fate. But his idea that all life on Earth evolved from a primordial ancestor and that we humans are distant cousins of apes, whales and even deep-sea mollusks is still a big ask for a lot of people.
Even when we intellectually accept these precepts of science, we subconsciously cling to our intuitions — what researchers call our naive beliefs. A study by Andrew Shtulman of Occidental College showed that even students with an advanced science education had a hitch in their mental gait when asked to affirm or deny that humans are descended from sea animals and that the Earth goes around the sun. Both truths are counterintuitive. The students, even those who correctly marked “true,” were slower to answer those questions than questions about whether humans are descended from tree-dwelling creatures (also true but easier to grasp) and whether the moon goes around the Earth (also true but intuitive).
Shtulman’s research indicates that as we become scientifically literate, we repress our naive beliefs but never eliminate them entirely. They nest in our brains, chirping at us as we try to make sense of the world.
Most of us do that by relying on personal experience and anecdotes, on stories rather than statistics. We might get a prostate-specific antigen test, even though it’s no longer generally recommended, because it caught a close friend’s cancer — and we pay less attention to statistical evidence, painstakingly compiled through multiple studies, showing that the test rarely saves lives but triggers many unnecessary surgeries. Or we hear about a cluster of cancer cases in a town with a hazardous-waste dump, and we assume that pollution caused the cancers. Of course, just because two things happened together doesn’t mean one caused the other, and just because events are clustered doesn’t mean they’re not random. Yet we have trouble digesting randomness; our brains crave pattern and meaning.
Even for scientists, the scientific method is a hard discipline. They, too, are vulnerable to confirmation bias — the tendency to look for and see only evidence that confirms what they already believe. But unlike the rest of us, they submit their ideas to formal peer review before publishing them. Once the results are published, if they’re important enough, other scientists will try to reproduce them — and, being congenitally skeptical and competitive, will be very happy to announce that they don’t hold up. Scientific results are always provisional, susceptible to being overturned by some future experiment or observation. Scientists rarely proclaim an absolute truth or an absolute certainty. Uncertainty is inevitable at the frontiers of knowledge.
That provisional quality of science is another thing a lot of people have trouble with. To some climate-change skeptics, for example, the fact that a few scientists in the 1970s were worried (quite reasonably, it seemed at the time) about the possibility of a coming ice age is enough to discredit what is now the consensus of the world’s scientists: The planet’s surface temperature has risen by about 1.5 degrees Fahrenheit in the past 130 years, and human actions, including the burning of fossil fuels, are extremely likely to have been the dominant cause since the mid-20th century.
It’s clear that organizations funded in part by the fossil-fuel industry have deliberately tried to undermine the public’s understanding of the scientific consensus by promoting a few skeptics. The news media gives abundant attention to such mavericks, naysayers, professional controversialists and table thumpers. The media would also have you believe that science is full of shocking discoveries made by lone geniuses. Not so. The (boring) truth is that science usually advances incrementally, through the steady accretion of data and insights gathered by many people over many years. So it has with the consensus on climate change. That’s not about to go poof with the next thermometer reading.
But industry PR, however misleading, isn’t enough to explain why so many people reject the scientific consensus on global warming.
The “science communication problem,” as it’s blandly called by the scientists who study it, has yielded abundant new research into how people decide what to believe — and why they so often don’t accept the expert consensus. It’s not that they can’t grasp it, according to Dan Kahan of Yale University. In one study he asked 1,540 Americans, a representative sample, to rate the threat of climate change on a scale of zero to 10. Then he correlated that with the subjects’ science literacy. He found that higher literacy was associated with stronger views — at both ends of the spectrum. Science literacy promoted polarization on climate, not consensus. According to Kahan, that’s because people tend to use scientific knowledge to reinforce their worldviews.
Americans fall into two basic camps, Kahan says. Those with a more “egalitarian” and “communitarian” mind-set are generally suspicious of industry and apt to think it’s up to something dangerous that calls for government regulation; they’re likely to see the risks of climate change. In contrast, people with a “hierarchical” and “individualistic” mind-set respect leaders of industry and don’t like government interfering in their affairs; they’re apt to reject warnings about climate change, because they know what accepting them could lead to — some kind of tax or regulation to limit emissions.
In the United States, climate change has become a litmus test that identifies you as belonging to one or the other of these two antagonistic tribes. When we argue about it, Kahan says, we’re actually arguing about who we are, what our crowd is. We’re thinking: People like us believe this. People like that do not believe this.
Science appeals to our rational brain, but our beliefs are motivated largely by emotion, and the biggest motivation is remaining tight with our peers. “We’re all in high school. We’ve never left high school,” says Marcia McNutt. “People still have a need to fit in, and that need to fit in is so strong that local values and local opinions are always trumping science. And they will continue to trump science, especially when there is no clear downside to ignoring science.”
Meanwhile the Internet makes it easier than ever for science doubters to find their own information and experts. Gone are the days when a small number of powerful institutions — elite universities, encyclopedias and major news organizations — served as gatekeepers of scientific information. The Internet has democratized it, which is a good thing. But along with cable TV, the Web has also made it possible to live in a “filter bubble” that lets in only the information with which you already agree.
How to penetrate the bubble? How to convert science skeptics? Throwing more facts at them doesn’t help. Liz Neeley, who helps train scientists to be better communicators at an organization called Compass, says people need to hear from believers they can trust, who share their fundamental values. She has personal experience with this. Her father is a climate-change skeptic and gets most of his information on the issue from conservative media. In exasperation she finally confronted him: “Do you believe them or me?” She told him she believes the scientists who research climate change and knows many of them personally. “If you think I’m wrong,” she said, “then you’re telling me that you don’t trust me.” Her father’s stance on the issue softened. But it wasn’t the facts that did it.
If you’re a rationalist, there’s something a little dispiriting about all this. In Kahan’s descriptions of how we decide what to believe, what we decide sometimes sounds almost incidental. Those of us in the science-communication business are as tribal as anyone else, he told me. We believe in scientific ideas not because we have truly evaluated all the evidence but because we feel an affinity for the scientific community. When I mentioned to Kahan that I fully accept evolution, he said: “Believing in evolution is just a description about you. It’s not an account of how you reason.”
Maybe — except that evolution is real. Biology is incomprehensible without it. There aren’t really two sides to all these issues. Climate change is happening. Vaccines save lives. Being right does matter — and the science tribe has a long track record of getting things right in the end. Modern society is built on things it got right.
Doubting science also has consequences, as seen in recent weeks with the measles outbreak that began in California. The people who believe that vaccines cause autism — often well educated and affluent, by the way — are undermining “herd immunity” to such diseases as whooping cough and measles. The anti-vaccine movement has been going strong since a prestigious British medical journal, the Lancet, published a study in 1998 linking a common vaccine to autism. The journal later retracted the study, which was thoroughly discredited. But the notion of a vaccine-autism connection has been endorsed by celebrities and reinforced through the usual Internet filters. (Anti-vaccine activist and actress Jenny McCarthy famously said on “The Oprah Winfrey Show,” “The University of Google is where I got my degree from.”)
In the climate debate, the consequences of doubt are likely to be global and enduring. Climate-change skeptics in the United States have achieved their fundamental goal of halting legislative action to combat global warming. They haven’t had to win the debate on the merits; they’ve merely had to fog the room enough to keep laws governing greenhouse gas emissions from being enacted.
Some environmental activists want scientists to emerge from their ivory towers and get more involved in the policy battles. Any scientist going that route needs to do so carefully, says Liz Neeley. “That line between science communication and advocacy is very hard to step back from,” she says. In the debate over climate change, the central allegation of the skeptics is that the science saying it’s real and a serious threat is politically tinged, driven by environmental activism and not hard data. That’s not true, and it slanders honest scientists. But the claim becomes more likely to be seen as plausible if scientists go beyond their professional expertise and begin advocating specific policies.
It’s their very detachment, what you might call the cold-bloodedness of science, that makes science the killer app. It’s the way science tells us the truth rather than what we’d like the truth to be. Scientists can be as dogmatic as anyone else — but their dogma is always wilting in the hot glare of new research. In science it’s not a sin to change your mind when the evidence demands it. For some people, the tribe is more important than the truth; for the best scientists, the truth is more important than the tribe.

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Was this Star Nibiru? Scientists Discover Star Made Closest Approach to Our Solar System 70,000 Years Ago

February 17, 2015 / / 0 Comments


Astronomers identify the closest known flyby of a star to our solar system Photo Credit: Flickr


Excerpt from americanlivewire.com

A low-mass red dwarf star passed through the outer Oort Cloud 70,000 years back in the closest approach made by any star into our system, discovers a team of researchers from various countries.

Lying in the constellation Monoceros and known as Scholtz’s star, it is a part of a binary system and has 8% the mass of the sun. Its companion, a brown dwarf, is said to have 6%.
The lowest end of the stellar spectrum, brown dwarfs are larger than gas giants but not as much so as to sustain hydrogen fusion for a larger period of time.

Due to its faint appearance, Scholtz’s star was discovered only a year ago by astronomer Ralf Dieter-Scholz in Potsdam, Germany, through the use of NASA’s WISE (Wide Field Infrared Survey Explorer), which mapped the entire sky in infrared during the years 2010 and 2011.

At the same time, the radial velocity of the star depicted that it was moving away from the solar system much faster than expected.
These motions led the researchers to conclude that either the star is headed toward our system, or moving away from it.

After analyzing the data, Mamajek concluded, “…The radial velocity measurements were consistent with it running away from the Sun’s vicinity–and we realized it must have had a close flyby in the past.”

Through the use of computer models, it was seen that the star passed about 5 trillion miles from our solar system around 70,000 years ago.

Mamajek and his team are 98 percent certain Scholtz’s star traveled through the outer Oort Cloud.

Although Scholtz’s star is 10th magnitude, too dim to be seen with the naked eye, it is magnetically active, which can cause it to flare at times and become significantly brighter. If this happened during its close approach to our solar system, prehistoric humans might have actually seen it.

The researchers published their findings in Astrophysical Journal Letters.

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6 Supermaterials That Could Change Our World

February 3, 2015 / / 0 Comments


Graphene

Excerpt from gizmodo.com

Graphene isn't the only game-changing material to come out of a lab. From aerogels nearly as light as air to metamaterials that manipulate light, here are six supermaterials that have the potential to transform the world of the future.

Self-healing Materials — Bioinspired Plastics

6 Supermaterials That Could Change Our World 
Self-healing plastic. Image credit: UIUC


The human body is very good at fixing itself. The built environment is not. Scott White at the University of Illinois at Urbana Champlain has been engineering bioinspired plastics that can self-heal. Last year, White's lab created a new polymer that oozes to repair a visible hole. The polymer is embedded with a vascular system of liquids that when broken and combined, clot just like blood. While other materials have been able to heal microscopic cracks, this new one repaired a hole 4 millimeter wide with cracks radiating all around it. Not big deal for a human skin, but a pretty big deal for plastic.

Engineers have also been envisioning concrete, asphalt, and metal that can heal themselves. (Imagine a city with no more potholes!) The rub, of course, lies in making them cheap enough to actually use, which is why the first applications for self-healing materials are most likely to be in space or in remote areas on Earth. 

Thermoelectric Materials — Heat Scavengers

6 Supermaterials That Could Change Our World 
Power blocks with thermoelectric material sued inside Alphabet Energy 's generator. Image credit: Alphabet Energy


If you've ever had a laptop burn up in your lap or touched the hot hood of car, then you've felt evidence of waste. Waste heat is the inevitable effect of running any that device that uses power. One estimate puts the amount of waste heat as two-thirds of all energy used. But what if there was a way to capture all that wasted energy? The answer to that "what if" is thermoelectric materials, which makes electricity from a temperature gradient.

Last year, California-based Alphabet Energy introduced a thermoelectric generator that plugs right into the exhaust pipe of ordinary generator, turning waste heat back into useful electricity. Alphabet Energy's generator uses a relatively cheap and naturally occurring thermoelectric material called tetrahedrite. Alphabet Energy says tetrahedrite can reach 5 to 10 percent efficiency.
Back in the lab, scientists have also been tinkering with another promising and possibly even more efficient thermoelectric material called skutterudite, which is a type of mineral that contains cobalt. Thermoelectric materials have already had niche applications—like on spacecraft—but skutterudite could get cheap and efficient enough to be wrapped around the exhaust pipes of cars or fridges or any other power-hogging machine you can think of. [Nature, MIT Technology Review, New Scientist]

Perovskites — Cheap Solar Cells

6 Supermaterials That Could Change Our World 
Solar cells made of perovskites. Image credit: University of Oxford


The biggest hurdle in moving toward renewable energy is, as these things always are, money. Solar power is getting ever cheaper, but making a plant's worth of solar cells from crystalline silicon is still an expensive, energy-intensive process. There's an alternative material that has the solar world buzzing though, and that's perovskites. 

Perovskites were first discovered over a century ago, but scientists are only just realizing its potential. In 2009, solar cells made from perovskites had a solar energy conversion efficiency of a measly 3.8 percent. In 2014, the number had leapt to 19.3 percent. That may not seem like much compared to traditional crystalline silicon cells with efficiencies hovering around 20 percent, but there's two other crucial points to consider: 1) perovskites have made such leaps and bounds in efficiency in just a few years that scientist think it can get even better and 2) perovskites are much, much cheaper. 

Perovskites are a class of materials defined by a particular crystalline structure. They can contain any number of elements, usually lead and tin for perovskites used in solar cells. These raw materials are cheap compared to crystalline silicon, and they can be sprayed onto glass rather than meticulously assembled in clean rooms. Oxford Photovoltaics is one of the leading companies trying to commercialize perovskites, which as wonderful as they have been in the lab, still do need to hold up in the real world. [WSJ, IEEE Spectrum, Chemical & Engineering News, Nature Materials]

Aerogels — Superlight and Strong

6 Supermaterials That Could Change Our World 
Image credit: NASA

Aerogels look like they should not be real. Although ghostly and ethereal, they can easily withstand the heat of a blowtorch and the weight of a car. The material is almost what exactly the name implies: gels where where the liquid has been replaced entirely by air. But you can see why it's also been called "frozen smoke" or "blue smoke." The actual matrix of an aerogel can be made of any number of substances, including silica, metal oxides, and, yes, also graphene. But the fact that aerogel is actually mostly made of air means that it's an excellent insulator (see: blowtorch). Its structure also makes it incredibly strong (see: car).

Aerogels do have one fatal flaw though: brittleness, especially when made from silica. But NASA scientists have been experimenting with flexible aerogels made of polymers to use insulators for spacecraft burning through the atmosphere. Mixing other compounds into even silica-based aerogels could make them more flexible. Add that to aerogel's lightness, strength, and insulating qualities, and that's one incredible material. [New Scientist, Gizmodo]

Metamaterials — Light Manipulators

If you've heard of metamaterials, you likely heard about it in a sentence that also mentioned "Harry Potter" and "invisibility cloak." And indeed, metamaterials, whose nanostructures are design to scatter light in specific ways, could possibly one day be used to render objects invisible—though it still probably wouldn't be as magical as Harry Potter's invisibility cloak. 

What's more interesting about metamaterials is that they don't just redirect visible light. Depending on how and what a particular metamaterial is made of, it can also scatter microwaves, radiowaves, or the little-known T-rays, which are between microwaves and infrared light on the electromagnetic spectrum. Any piece of electromagnetic spectrum could be manipulated by metamaterials. 

That could be, for example, new T-ray scanners in medicine or security or a compact radio antennae made of metamaterials whose properties change on the fly. Metamaterials are at the promising but frustrating cusp where the theoretical possibilities are endless, but commercialization is still a long, hard road. [Nature, Discover Magazine]

Stanene — 100 percent efficient conductor

6 Supermaterials That Could Change Our World 
The molecular structure of stanene. Image credit: SLAC


Like the much better known graphene, stanene is also made of a single layer of atoms. But instead of carbon, stanene is made of tin, and this makes all the difference in allowing stanene to possibly do what even wondermaterial extraordinaire graphene cannot: conduct electricity with 100 percent efficiency.

Stanene was first theorized in 2013 by Stanford professor Shoucheng Zhang, whose lab specializes in, along other things, predicting the electronic properties of materials like stanene. According to their models, stanene is a topological insulator, which means its edges are a conductor and its inside is an insulator. (Think of a chocolate-covered ice cream bar. Chocolate conductor, ice cream insulator.) 

This means stanene could conduct electricity with zero resistance even, crucially, at room temperature. Stanene's properties have yet to been tested experimentally—making a single-atom sheet tin is no easy task—but several of Zhang's predictions about other topological insulators have proven correct.

If the predictions about stanene bear out, it could revolutionize the microchips inside all your devices. Namely, the chips could get a lot more powerful. Silicon chips are limited by the heat created by electrons zipping around—work 'em too fast and they'll simply get too hot. Stanene, which conducts electricity 100 percent efficiency, would have no such problem. [SLAC, Physical Review Letters, Scientific American]

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The Best Star Gazing Binoculars for 2015

January 24, 2015 / / 0 Comments




Excerpt from space.com

Most people have two eyes. Humans evolved to use them together (not all animals do). People form a continuous, stereoscopic panorama movie of the world within in their minds. With your two eyes tilted upward on a clear night, there's nothing standing between you and the universe. The easiest way to enhance your enjoyment of the night sky is to paint your brain with two channels of stronger starlight with a pair of binoculars. Even if you live in — or near — a large, light-polluted city, you may be surprised at how much astronomical detail you'll see through the right binoculars!
Our editors have looked at the spectrum of current binocular offerings. Thanks to computer-aided design and manufacturing, there have never been more high-quality choices at reasonable prices. Sadly, there's also a bunch of junk out there masquerading as fine stargazing instrumentation. We've selected a few that we think will work for most skywatchers.
There was a lot to consider: magnification versus mass, field of view, prism type, optical quality ("sharpness"), light transmission, age of the user (to match "exit pupil" size, which changes as we grow older), shock resistance, waterproofing and more. 

The best binoculars for you

"Small" astronomy binoculars would probably be considered "medium" for bird watching, sports observation and other terrestrial purposes. This comes about as a consequence of optics (prism type and objective size, mostly). "Large" binoculars are difficult to use for terrestrial applications and have a narrow field of view. They begin to approach telescope quality in magnification, resolution and optical characteristics.

Most of our Editors' Choicesfor stargazing binoculars here are under $300. You can pay more than 10 times that for enormous binocular telescopes used by elite enthusiasts on special mounts! You'll also pay more for ruggedized ("mil spec," or military standard) binoculars, many of which suspend their prisms on shock mounts to keep the optics in precise alignment.

Also, our Editors' Choices use Porro prism optics. Compact binoculars usually employ "roof" prisms, which can be cast more cheaply, but whose quality can vary widely. [There's much more about Porro prisms in our Buyer's Guide.]
We think your needs are best served by reviewing in three categories.
  • Small, highly portable binoculars can be hand-held for viewing ease.
  • Medium binoculars offer higher powers of magnification, but still can be hand-held, if firmly braced.
  • Large binoculars have bigger "objective" lenses but must be mounted on a tripod or counterweighted arm for stability.
Here's a detailed look at our Editor's Choice selections for stargazing binoculars:

Best Small Binoculars 

Editor's Choice: Oberwerk Mariner 8x40 (Cost: $150)

Oberwerk in German means "above work." The brand does indeed perform high-level optical work, perfect for looking at objects above, as well as on the ground or water. Founder Kevin Busarow's Mariner series is not his top of the line, but it benefits greatly from engineering developed for his pricier models. The Oberwerk 8x40’s treat your eyes to an extremely wide field, at very high contrast, with razor-sharp focus; they are superb for observing the broad starscapes of the Milky Way. Just 5.5 inches (14 cm) from front to back and 6.5 inches wide (16.5 cm), the Mariners are compact and rugged enough to be your favorite "grab and go binoculars." But at 37 ounces, they may be more than a small person wants to carry for a long time.


Runner-Up: Celestron Cometron 7x50 (Cost: $30)

Yes, you read that price correctly! These Celestron lightweight, wide-field binoculars bring honest quality at a remarkably low price point. The compromise comes in the optics, particularly the prism's glass type (you might see a little more chromatic aberration around the edges of the moon, and the exit pupil isn't a nice, round circle). Optimized for "almost infinitely distant" celestial objects, these Cometrons won't focus closer than about 30 feet (9.1 meters).  But that's fine for most sports and other outdoor use. If you're gift-buying for multiple young astronomers – or you want an inexpensive second set for yourself – these binoculars could be your answer. Just maybe remind those young folks to be a little careful around water; Celestron claims only that the Cometrons are "water resistant," not waterproof. 


Honorable Mention: Swarovski Habicht 8x30 (Cost: $1,050)

From the legendary Austrian firm of Swarovski Optik, these "bins" are perfect. Really. Very sharp. Very lightweight. Very wide field. Very versatile. And very expensive! Our editors would have picked them if we could have afforded them. 

Honorable Mention: Nikon Aculon 7x50 (Cost: $110) 

Nikon's legendary optical quality and the large, 7mm exit pupil diameter make these appropriate as a gift for younger skywatchers. 

Best Medium Binoculars

Editor's Choice: Celestron SkyMaster 8x56 (Cost: $210)

A solid, chunky-feeling set of quality prisms and lenses makes these binoculars a pleasant, 38oz. handful. A medium wide 5.8 degrees filed of view and large 7mm exit pupil brings you gently into a sweet sky of bright, though perhaps not totally brilliant, stars. Fully dressed in a rubber wetsuit, these SkyMasters are waterproof. Feel free to take them boating or birding on a moist morning. Their optical tubes were blown out with dry nitrogen at the factory, then sealed. So you can expect them not to fog up, at least not from the inside. Celestron's strap-mounting points on the Skymaster 8x56 are recessed, so they don't bother your thumbs, but that location makes them hard to fasten. 


Runner-Up: Oberwerk Ultra 15x70 (Cost: $380)

The most rugged pair we evaluated, these 15x70s are optically outstanding. Seen through the Ultra's exquisitely multi-coated glass, you may find yourself falling in love with the sky all over again. Oberwerk's method of suspending their BAK4 glass Porro prisms offers greater shock-resistance than most competitors’ designs. While more costly than some comparable binoculars, they deliver superior value. Our only complaint is with their mass: At 5.5 lbs., these guys are heavy!  You can hand-hold them for a short while, if you’re lying down. But they are best placed on a tripod, or on a counterweighted arm, unless you like shaky squiggles where your point-source stars are supposed to be. Like most truly big binoculars, the eyepieces focus independently; there’s no center focus wheel. These "binos" are for true astronomers. 


Honorable Mention: Vixen Ascot 10x50 (Cost:$165)

These quirky binoculars present you with an extremely wide field. But they are not crash-worthy – don't drop them in the dark – nor are they waterproof, and the focus knob is not conveniently located. So care is needed if you opt for these Vixen optics. 

Best Large Binoculars

Don't even think about hand-holding this 156-ounce beast! The SkyMaster 25x100 is really a pair of side-by-side 100mm short-tube refractor telescopes. Factor the cost of a sturdy tripod into your purchase decision, if you want to go this big.  The monster Celestron comes with a sturdy support spar for mounting. Its properly multi-coated optics will haul in surprising detail from the sky.  Just make sure your skies are dark; with this much magnification, light pollution can render your images dingy. As with many in the giant and super-giant class of binoculars, the oculars (non-removable eyepieces) focus separately, each rotating through an unusually long 450 degrees.  Getting to critical focus can be challenging, but the view is worth it. You can resolve a bit of detail on face of the new moon (lit by "Earthshine") and pick out cloud bands on Jupiter; tha's pretty astonishing for binoculars. 


Runner-Up: Orion Astronomy 20x80 (Cost: $150)

These big Orions distinguish themselves by price point; they're an excellent value. You could pay 10 times more for the comparably sized Steiners Military Observer 20x80 binoculars! Yes, the Orions are more delicate, a bit less bright and not quite as sharp. But they do offer amazingly high contrast; you'll catch significant detail in galaxies, comets and other "fuzzies." Unusually among such big rigs, the Astronomy 20x80 uses a center focus ring and one "diopter" (rather than independently focusing oculars); if you’re graduating from smaller binoculars, which commonly use that approach, this may be a comfort. These binoculars are almost lightweight enough to hold them by hand. But don't do that, at least not for long periods. And don't drop them. They will go out of alignment if handled roughly. 


Honorable Mention: Barska Cosmos 25x100 (Cost: $230)

They are not pretty, but you're in the dark, right? Built around a tripod-mountable truss tube, these Barskas equilibrate to temperature quickly and give you decent viewing at rational cost. They make for a cheaper version of our Editors' Choice Celestron SkyMasters. 

Honorable Mention: Steiner Observer 20x80 (Cost: $1,500)

Not at all a practical cost choice for a beginning stargazer, but you can dream, can't you? These Steiner binoculars are essentially military optics "plowshared" for peaceful celestial observing. 

Why we chose NOT to review certain types

Image stabilized?

Binoculars with active internal image stabilization are a growing breed. Most use battery-powered gyroscope/accelerometer-driven dynamic optical elements. We have left this type out of our evaluation because they are highly specialized and pricey ($1,250 and up). But if you are considering active stabilization, you can apply the same judgment methods detailed in our Buyer's Guide.

Comes with a camera?

A few binoculars are sold with built-in cameras. That seems like a good idea. But it isn't, at least not for skywatching. Other than Earth's moon, objects in the night sky are stingy with their photons. It takes a lengthy, rock-steady time exposure to collect enough light for a respectable image. By all means, consider these binocular-camera combos for snapping Facebook shots of little Jenny on the soccer field. But stay away from them for astronomy.

Mega monster-sized?

Take your new binoculars out under the night sky on clear nights, and you will fall in love with the universe. You will crave more ancient light from those distant suns. That may translate into a strong desire for bigger stereo-light buckets.

Caution: The next level up is a quantum jump of at least one financial order of magnitude. But if you have the disposable income and frequent access to dark skies, you may want to go REALLY big. Binocular telescopes in this class can feature interchangeable matching eyepieces, individually focusing oculars, more than 30x magnification and sturdy special-purpose tripods. Amateurs using these elite-level stereoscopes have discovered several prominent comets.

Enjoy your universe

If you are new to lens-assisted stargazing, you'll find excellent enhanced views among the binocular choices above. To get in deeper and to understand how we picked the ones we did, jump to our Buyer's Guide: How to Choose Binoculars for Sky Watching.

You have just taken the first step to lighting up your brain with star fire. May the photons be with you. Always. 

Skywatching Events 2015

Once you have your new binoculars, it's time to take them for a spin. This year intrepid stargazers will have plenty of good opportunities to use new gear.

On March 20, for example, the sun will go through a total solar eclipse. You can check out the celestial sight using the right sun-blocking filters for binoculars, but NEVER look at the sun directly, even during a solar eclipse. It's important to find the proper filters in order to observe the rare cosmic show. 

Observers can also take a look at the craggy face of the moon during a lunar eclipse on April 4. Stargazers using binoculars should be able to pick out some details not usually seen by the naked eye when looking at Earth's natural satellite.

Skywatchers should also peek out from behind the binoculars for a chance to see a series of annual meteor showers throughout the year.

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Cloud castles: NASA wants to deploy manned solar-powered airships to Venus

December 21, 2014 / / 0 Comments


A model of a floating city in the atmosphere of Venus (Image from nasa.gov)
A model of a floating city in the atmosphere of Venus (Image from nasa.gov)


Excerpt from
rt.com 

Despite its hellish surface, Venus turns out to be quite an attractive planet for exploration. NASA scientists are developing a project of conquering its upper atmosphere – a fleet of solar-powered aircraft may build up a whole cloud city in the future.

The challenging conditions on Venus’ surface – that is, 92 Earth’s atmospheres of pressure, the sulphuric acid rain with lightning bolts and temperatures of nearly 500 C – made scientists literally turn to cloud castles. This idea has been recently developed in NASA’s High Altitude Venus Operational Concept (HAVOC) mission that is set to send a series of missions to the planet.

“The vast majority of people, when they hear the idea of going to Venus and exploring, think of the surface, where it’s hot enough to melt lead and the pressure is the same as if you were almost a mile underneath the ocean,” aerospace engineer at NASA Langley Research Center Chris Jones told IEEE Spectrum magazine. “I think that not many people have gone and looked at the relatively much more hospitable atmosphere and how you might tackle operating there for a while.”


First, HAVOC is set to send a robot to explore the atmosphere of Venus. It could be followed by a manned mission to orbit and a mission to the planet’s atmosphere – both would include a 30-day stay. Later on, a crew of two astronauts would spend a year in the atmosphere, and someday a whole human colony in a cloud city might be established. 

The remarkable vehicle that would carry out the mission is designed to be nearly 130 meters long, with a small 21-cubic-meter habitat for the crew and its top covered with more than 1,000 square meters of solar panels. As Venus is the second closest planet to the Sun, it gets 40 percent more solar power than the Earth – and 240 percent more than Mars. 

The astronauts on the Venus mission are unlikely to leave the aircraft, so – 50 kilometers from the planet’s surface – it would be safer than the expedition to Mars. According to the scientists, they would be studying the planet’s advanced greenhouse effect to better understand the Earth’s possible future.

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

December 3, 2014 / / 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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Let There Be Light: Sistine Chapel Gets LED Makeover ~ Video

November 3, 2014 / / 0 Comments




Excerpt from euronews.com
Visitors to the Vatican’s Sistine Chapel will now be able to see its world-famous frescos in a new light – 7,000 new LED lights to be exact. 

Ultraviolet rays were slowly fading the colours of the more than 500-year-old masterpieces by Renaissance greats like Michaelangelo, Botticelli and Ghirlandaio. 

“This type of LED lighting guarantees a homogeneous lighting, which is very precise and allows us to understand the Sistine Chapel as a whole and each fresco individually, in minute detail,” says the Director of the Vatican Museums, Antonio Paolucci. 

The non-intrusive, energy-saving bulbs have been concealed along the edges of the ledge which runs around the chapel. Positioned to match the frescoes’ pigments, they can be adjusted to different levels. 

“This LED lighting, through complex technology, makes the lights emit a solar spectrum which is as close as possible to natural light. So there aren’t any disproportionate amounts of reds or blues. 
Usually LED lights are perceived as cold because they’re too blue,” says Vittoria Cimino, Director of the Conservator’s Office of the Vatican Museums.

“The light quality was especially designed for this chapel, we had at least 280 different pigments, testing and calculating a new colour rendering index, especially for this chapel,” says Osram light engineer Martin Reuter. 




Click to zoom

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Clear & Bright Skies Observed on a Neptune-sized Exoplanet

September 25, 2014 / / 0 Comments

Excerpt from the journal Naturenature.comTransmission spectroscopy has so far detected atomic and molecular absorption in Jupiter-sized exoplanets, but intense efforts to measure molecular absorption in the atmospheres of smaller (Neptune-sized) pla...

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NASA: Water Vapor Found on Neptune-size Alien Planet

September 24, 2014 / / 0 Comments



space.com

By Nola Taylor Redd, Space.com Contributor 

 A Neptune-size planet beyond the solar system has telltale traces of water vapor in its atmosphere, making it the smallest exoplanet known to have the wet stuff yet, scientists say.

Several massive Jupiter-size giants have had the components of their atmosphere examined, but until now, the atmospheres of smaller planets have proved more elusive. In this new study, scientists discovered traces of water on the alien planet HAT-P-11b, which orbits a star 124 light-years from Earth in the constellation Cygnus.

"Water is the most cosmically abundant molecule that we can directly observe in exoplanets, and we expect it to be prevalent in the upper atmospheres of planets at these temperatures," lead author Jonathan Fraine said in an email interview. Fraine, a graduate student at the University of Maryland, worked with a team lead by Drake Deming, also of the University of Maryland. 

"Detecting it is both a confirmation of our theories and revealing for the bulk of the spectrum that we can observe," Fraine told Space.com.

This artist’s illustration depicts the alien planet HAT-P-11b, which shows signs of water in its atmosphere, as the exoplanet crosses in front of its parent star.
This artist’s illustration depicts the alien planet HAT-P-11b, which shows signs of water in its atmosphere, as the exoplanet crosses in front of its parent star. As starlight passes through the puffed-up atmosphere surrounding the planet, shown here in orange, scientists can detect its composition.
Credit: NASA/JPL-Caltech

Detecting alien planet atmospheres

This image from the Hubble Space Telescope shows the star HAT-P-11 (center), which has a Neptune-size planet that is the smallest yet known to have water in its atmosphere. The planet, HAT-P-11b, is not visible in this image. The other bright object seen here is another star.
Credit: NASA, ESA, J. Fraine

As a planet passes, or transits, between Earth and its sun, it blocks light from the star. The dip in light is how many exoplanets are first found. But these transits also allow astronomers to study the atmospheres of exoplanets. By observing the spectrum of light that passes through an exoplanet’s atmosphere, scientists can determine what it is made up of.


For HAT-P-11b, a planet roughly four times the radius of Earth, that makeup is 90 percent hydrogen, with traces of water vapor. The Neptune-size planet orbits its sun every five days, at a distance that is only one-twentieth of the Earth-sun distance (which is 93 million miles, or 150 million kilometers). As a result, the temperature climbs higher on HAT P-11b than it does on gas giants in the solar system, reaching a sizzling 1,120 degrees Fahrenheit (605 degrees Celsius).

Scientists have been studying the atmospheres of Jupiter-like planets for years, but smaller planets produce a smaller signal that is more challenging to observe. For the new study, researchers examined the atmospheres of four other smaller exoplanets — two roughly the size of Neptune and two smaller super-Earths — but the results were disappointingly featureless.

"We do indeed have the technology — the resolution — to observe Neptune-size exoplanets, and even super-Earths," Fraine said.

But the chemical compositions of the other four planets were blocked by a familiar phenomenon — clouds.

"We've just been seeing a whole lot of nothing," Eliza Kempton, of Grinnell College in Iowa. Kempton models planetary atmospheres but was not involved in the research.

This artist's illustration shows what the skies may look like on different alien planets. On the left is a cloudy planet, while on the right is a planet with clear skies that may resemble the sky of exoplanet HAT-P-11b, a Neptune-size world thought to hav
This artist's illustration shows what the skies may look like on different alien planets. On the left is a cloudy planet, while on the right is a planet with clear skies that may resemble the sky of exoplanet HAT-P-11b, a Neptune-size world thought to have water in its atmosphere.
Credit: NASA


Kempton added that the flat, featureless signals observed for the other planets were attributed to clouds or hazes in the upper atmosphere. The high clouds blocked light from the star, keeping it from penetrating through to the observers' side of the planet and leaving scientists unable to characterize the chemicals in the atmosphere.

"It's not crazy to think that there should be clouds in these exoplanet atmospheres, because we see clouds in all the planetary atmospheres in our solar system," Kempton said.

Although the hot, Neptune-size planet lives in a different environment from the icy giants in the solar system, it is similar to one of the four smaller planets whose atmosphere had already been studied. Those planets are known as GJ436b, GJ1214b, HD97658b and GJ3470b.

HAT-P-11b is only slightly larger and warmer than the alien planet GJ436b, making them good to compare to one another because one has clouds and one does not, Fraine said.

"I like to consider them the bigger version of the Earth-Venus twin pair," Fraine said of the planets HAT-P-11b and GJ436b.

"They are basically the same mass, radius and temperature, but small changes in the formation, or even these bulk properties, may be causing vast changes in the atmospheric composition."

The research is detailed in the Sept. 25 issue of the journal Nature, along with a commentary article by Kempton.

 A planet's upper atmosphere results from what happens both above and below it. The balancing act involves irradiation from its star and from cosmic rays on the outside, as well as the chemical and dynamical systems lower in the atmosphere, Fraine explained.

"If we know the input from above — the host star — and the upper atmosphere from our observations, then the missing piece of the puzzle is the interior composition," he said.
Although the interior of a planet is complex, Fraine called the newly characterized atmosphere "a great step forward in solving the puzzle."

The composition of the small planet's atmosphere also supports the core accretion model of planetary formation, where smaller particles combine to create larger and larger particles, eventually reaching planet-size proportions.

"Core accretion predicts that planets are built from the inside out," Fraine said.

"Measuring that HAT P-11b likely has a relatively hydrogen-poor atmosphere implies that it was formed from rocky material that later acquired a thick atmosphere above it, which is what the core-accretion model predicts."

Had the planet formed along the lines of the competing gravitational instability model, its composition and that of its atmosphere should bear a stronger similarity to its star than what was measured by scientists.

Because of its crucial role in the balancing act, the water vapor detected in the exoplanet's atmosphere played an important part in modeling its formation and evolution.

"In the long run, if we can detect water, methane, carbon monoxide, carbon dioxide, etc., in dozens to hundreds of exoplanet atmospheres of various bulk properties, then we will be able to paint a much clearer picture of how planets form, and, likewise, how Earth formed," Fraine said.

"This was just one of the beginning brush strokes to painting the full picture of how planets, as well as ourselves, were formed."

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10 Signs That You’re Fully Awake

September 24, 2014 / / 0 Comments

A great article from www.pakalertpress.comIsn’t it obvious that there is a significant global awakening happening? Just as the Mayans predicted so many years ago, the apocalypse would become apparent in 2012. But many misinterpret the apocalypse to be the end of the world, when in fact it actually means an “un-covering, a revelation of something hidden.”As many continue to argue the accuracy of the Mayan calendar, it can no longer be argued that a great many people are finally [...]

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