Photo : NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI Excerpt from sciencetimes.com Originally discovered in 1801 by an astronomer in Sicily, Ceres has had quite an interesting history to date. Originally believed to be a shining star in the sky, when i...
Tag: Scientist (page 4 of 13)
Excerpt from nbcnews.com
By Katie Linendoll
FOUNTAIN HILLS, Ariz. — If words like UFO, extraterrestrial, crops circles and abductee have ever piqued your paranormal interest, do yourself a favor and head to the International UFO Congress.
The annual conference—which holds the Guinness record for being the largest convention dedicated to unidentified flying objects—takes place in the picturesque desert town of Fountain Hills, and this year it ran from Feb. 18 to 22. It's worth noting that Arizona is known as a hotbed of activity when it comes to sightings. Thousands flock to the annual event, which is produced by Open Minds, a paranormal research organization.
Each attendee has his or her own reason for being there. My goal was to find out if modern science and technology have changed the game when it comes to UFO sightings and evidence gathering.
"A lot of people think, go to a UFO convention, it's going to be tinfoil hats, but that's not what this is. We have NASA astrobiologists speak, scientists, high-ranking military officials, the works. I mean, there's a lot of really credible people covering this subject," said UFO Congress co-organizer and paranormal journalist Maureen Elsberry.
Air Force UFO documents now available online
When attending a UFO conference, the best approach is to come in with an open mind, ask lots of questions and talk with people about why they are there. Everyone has a story, from the speakers to the attendees, and even the vendors (some of whom double as ufologists).
The highlight of this year's conference was undeniably the speaker series, and it was standing room only to see one man, Bob Lazar. Lazar first spoke out in 1989, claiming that he'd worked as a government scientist at a secret mountainside facility south of Area 51's main site, where he saw remarkably advanced UFO technology. Critics have sought to discredit Lazar, questioning his employment record and educational credentials.
During the conference, George Knapp, an investigative TV reporter in Las Vegas who broke the Lazar story in '89, led an onstage question-and-answer session with Lazar, who discussed the work he did at a place called S4. Lazar spoke in detail about the alien UFO hangars and UFO propulsion systems he was allegedly asked to reverse engineer, and even loosely sketched them out for the audience.
"All the science fiction had become reality," said Lazar, who was noticeably uncomfortable and clearly surprised by the fact that, decades later, he remains such a draw.
You never know whom you'll bump into at the Congress. In the vendor hall, I met sculptor Alan Groves, who traveled all the way from Australia to peddle his "true to scale" Zetan alien figurines. I wondered if his side gig was lucrative, only to realize he was selling the figures like hotcakes. Then we talked about his day job, and he told me he's worked on special and creature effects for films such as "Star Wars," "Alien," "Labyrinth" and "Jurassic Park."
Many of the attendees told me that hard evidence is a requirement for ufologists and paranormal field experts. Derrel Sims, also known as Alien Hunter, told me he spent two years in the CIA, and also has served as a police officer and licensed private investigator.
He said his first alien encounter happened at age 4, and others in his family have also seen aliens. In 38-plus years of alien research, Sims has learned this: "If you look, the evidence is there." To date, he said, more than 4,000 pieces of that evidence exist.
Sims is adamant about only working with evidence-based methods, using DNA tests and collecting samples as well as relying on ultraviolet, infrared and x-ray tools in his research. He said that, in 1992, he discovered aliens leave their own kind of fluorescent fingerprint, and he continues to test for these clues. He added that if you have had an alien encounter, it's important to react quickly to gather evidence: "fluorescence" stays on the skin for only 24 hours. He said that other marks aliens leave include "scoop" marks, which are an identifying thread some abductees have in common.
Another commonality he's discovered is heritage. He said that, in his research, he has found 45 percent of all abductions happen to Native Americans, Irish and Celtic people, and he said that women also have a higher chance of being abducted.
When it comes to filming hard-to-explain phenomena, Patty Greer, who makes documentaries about crop circles, said that quadcopters — a.k.a. drones — have added production value to her films. Lynne Kitei, who covered a mass UFO sighting in her book and in the documentary The Phoenix Lights, said that even low-tech tools, like the 35mm film she used, are still a reliable way to gather proof of inexplicable flying craft, especially because they offer something an iPhone doesn't: negatives.
White House responds to UFO request
Night vision also offers added opportunities for UFO researchers, according to Ben Hansen, who was the host and lead investigator of SyFy channel's "Fact or Faked: Paranormal Files." He's now the owner of Night Vision Ops, an online store that sells night-vision technology. Hansen said that the consumer accessibility of new military-grade technologies in thermal and light amplification scopes are upping the game for the everyday UFO enthusiast.
To close out an intense few days on site at the Congress, Hansen's team invited me to a night watch near Arizona's Superstition Mountains. It was fascinating to see the latest optics add incredible clarity to the night sky, amplifying available light up to 50,000 times beyond what the unaided eye can see. Using the right technology, we were also able to see that a certain flying object, which made everyone nearby jump, wasn't a UFO after all. It was a bat.
I was surrounded by some serious tech all weekend, and it was eye-opening to see the ways that UFO hunters are gathering scientific evidence to learn more about the paranormal world. But I have to say, the gadget that was the most useful to me at the conference was my iPhone, which I used to download a free nightlight app for kids. For the few hours I managed to sleep, it was with the soothing illumination provided by "Kiwi the Green Koala." In short, I was officially freaked out.
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| Mercury's extreme temperatures and lack of an atmosphere would make it very difficult, if not impossible, for people to live on the planet. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington |
Excerpt from space.com
By Joseph Castro, Space.com Contributor
Have you ever wondered what it might be like to homestead on Mars or walk on the moons of Saturn? So did we. This is the first in Space.com's 12-part series on what it might be like to live on or near planets in our solar system, and beyond. Check back each week for the next space destination.
With its extreme temperature fluctuations, Mercury is not likely a planet that humans would ever want to colonize. But if we had the technology to survive on the planet closest to the sun, what would it be like to live there?To date, only two spacecraft have visited Mercury. The first, Mariner 10, conducted a series of Mercury flybys in 1974, but the spacecraft only saw the lit half of the planet. NASA's MESSENGER spacecraft, on the other hand, conducted flybys and then entered Mercury's orbit — in March of 2013, images from the spacecraft allowed scientists to completely map the planet for the first time.
MESSENGER photos of Mercury show that the planet has water ice at its poles, which sit in permanent darkness. Mining this ice would be a good way to live off the land, but setting up bases at the poles might not be a good idea, said David Blewett, a participating scientist with the Messenger program.
"The polar regions would give you some respite from the strength of the sun on Mercury," Blewett told Space.com. "But, of course, it's really cold in those permanently shadowed areas where the ice is, and that presents its own challenge."
A better option, he said, would probably be to set up a home base not far from one of the ice caps, perhaps on a crater rim, and have a water mining operation at the pole.
Still, dealing with extreme temperatures on Mercury would likely be unavoidable: Daytime temperatures on the planet can reach 800 degrees Fahrenheit (430 degrees Celsius), while nighttime temperatures can drop down to minus 290 degrees Fahrenheit (minus 180 degrees Celsius).
Scientists once believed Mercury was tidally locked with the sun, meaning that one side of the planet always faces the sun because it takes the same amount of time to rotate around its axis as it does to revolve around the star. But we now know that Mercury's day lasts almost 59 Earth days and its year stretches for about 88 Earth days.
Interestingly, the sun has an odd path through the planet's sky over the course of Mercury's long day, because of the interaction between Mercury's spin rate and its highly elliptical orbit around the sun.
"It [the sun] rises in the east and moves across the sky, and then it pauses and moves backwards just a tad. It then resumes its motion towards the west and sunset," said Blewett, adding that the sun appears 2.5 times larger in Mercury's sky than it does in Earth's sky.
And during the day, Mercury's sky would appear black, not blue, because the planet has virtually no atmosphere to scatter the sun's light. "Here on Earth at sea level, the molecules of air are colliding billions of times per second," Blewett said. "But on Mercury, the atmosphere, or 'exosphere,' is so very rarefied that the atoms essentially never collide with other exosphere atoms." This lack of atmosphere also means that the stars wouldn't twinkle at night.
But Mercury isn't devoid of natural disasters. "The surface is exposed to impacts of all sizes," Blewett said. It also may suffer from earthquakes due to compressive forces that are shrinking the planet (unlike Earth, Mercury doesn't have tectonic activity).
Mercury is about two-fifths the size of Earth, with a similar gravity to Mars, or about 38 percent of Earth's gravity. This means that you could jump three times as high on Mercury, and heavy objects would be easier to pick up, Blewett said. However, everything would still have the same mass and inertia, so you could be knocked over if someone threw a heavy object at you, he added.
Finally, you can forget about a smooth Skype call home: It takes at least 5 minutes for signals from Mercury to reach Earth, and vice versa.
Excerpt from huffingtonpost.comScientists in the U.K. have examined a tiny metal circular object, and are suggesting it might be a micro-organism deliberately sent by extraterrestrials to create life on Earth.Don't be fooled by the size of the objec...
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.
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)
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.
Excerpt from cambridge-news.co.ukWhat is known as Active Seti will be under serious discussion this week at the annual meeting of the American Association for the Advancement of Science (AAAS) in San Jose, California. Seti spokesman Dr Seth...
Excerpt from space.com
The idea of building a lunar outpost has long captured people's imaginations. But what would it really be like to live on the moon?
Space exploration has long focused on the moon, with Earth's satellite the setting for a number of significant missions. A 1959 Soviet spacecraft photographed the moon's far side for the first time, and in 1969, NASA landed people on the lunar surface for the first time. Numerous missions followed, including NASA's Lunar Reconnaissance Orbiter that beamed home the highest-resolution topographical lunar map to date, covering 98.2 percent of the moon's surface.
Altogether, data beamed back from numerous missions suggest that no place on the moon would be a pleasant place to live, at least compared with Earth. Lunar days stretch for about 14 Earth days with average temperatures of 253 degrees Fahrenheit (123 degrees Celsius), while lunar nights also last 14 Earth days (due to the moon's rotation) and maintain a frigid cold of minus 387 degrees Fahrenheit (minus 233 degrees Celsius).
"About the only place we could build a base that wouldn't have to deal with these extremes is, oddly enough, near the lunar poles," said Rick Elphic, project scientist for NASA's LADEE probe, which studied the moon's atmosphere and dust environment before performing a planned crash into the natural satellitein April 2014. These areas likely store vast amounts of water-ice and enjoy low levels of light from the sun for several months at a time.
"Instead of the blazing heat of lunar noon, it is a kind of perpetual balmy sunset, with temperatures around 0 degrees Celsius [32 degrees Fahrenheit] due to the low angle of the sun," Elphic added.
Vacations away from pole outposts would offer up sights unlike anything on Earth. Decorating the moon's vast lava plains are large impact-borne "mountains," the tallest of which is 3.4 miles (5.5 kilometers) high, about the size of Mount Saint Elias on the border of Alaska and Canada. "Skylight" holes puncture some of the plains where lava likely drained into sub-surface caverns — the perfect adventure for lunar spelunkers.
The moon also sports huge craters, such as the 25-mile-wide (40 km) Aristarchus crater. A view from the rim of Aristarchus would "dwarf the Grand Canyon and make Meteor Crater in Arizona look like a hole in a putting green," Elphic told Space.com via email.
Lunar athletes would not need to check the forecast, however. Because of its very tenuous atmosphere, the moon has no weather. "Every day is sunny with no chance of rain!" Elphic added. You would, however, have to look out for so-called space weather, which includes meteor particles that can be as large as golf balls and highly energetic particles from solar flares.
Another potential danger would be moonquakes. Seismometers left on the lunar surface during Apollo show that the moon is still seismically active, and even has rare, hour-long quakes measuring up to 5.5 on the Richter scale. These quakes would be strong enough to cause structural damage to buildings.
"So don't leave Earth for your home on the moon thinking you've left seismic activity behind," Elphic said. "Make sure your lunar house is up to code."
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| Planck has mapped the delicate polarisation of the CMB across the entire sky |
Excerpt from bbc.com
Scientists working on Europe's Planck satellite say the first stars lit up the Universe later than previously thought.
Earlier observations of this radiation had suggested the first generation of stars were bursting into life by about 420 million years after the Big Bang.
Planck's data indicates this great ignition was well established by some 560 million years after it all began.
"This difference of 140 million years might not seem that significant in the context of the 13.8-billion-year history of the cosmos, but proportionately it's actually a very big change in our understanding of how certain key events progressed at the earliest epochs," said Prof George Efstathiou, one of the leaders of the Planck Science Collaboration.
Subtle signal
The assessment is based on studies of the "afterglow" of the Big Bang, the ancient light called the Cosmic Microwave Background (CMB), which still washes over the Earth today.
Prof George Efstathiou: "We don't need more complicated explanations"
It contains a wealth of information about early conditions in the Universe, and can even be used to work out its age, shape and do an inventory of its contents.
Scientists can also probe it for very subtle "distortions" that tell them about any interactions the CMB has had on its way to us.
Forging elements
One of these would have been imprinted when the infant cosmos underwent a major environmental change known as re-ionisation.
Prof Richard McMahon: "The two sides of the bridge now join"
These hot giants would have burnt brilliant but brief lives, producing the very first heavy elements. But they would also have "fried" the neutral gas around them - ripping electrons off the hydrogen protons.
And it is the passage of the CMB through this maze of electrons and protons that would have resulted in it picking up a subtle polarisation.
Impression: The first stars would have been unwieldy behemoths that burnt brief but brilliant lives The Planck team has now analysed this polarisation in fine detail and determined it to have been generated at 560 million years after the Big Bang.
The American satellite WMAP, which operated in the 2000s, made the previous best estimate for the peak of re-ionisation at 420 million years.
The problem with that number was that it sat at odds with Hubble Space Telescope observations of the early Universe.
Hubble could not find stars and galaxies in sufficient numbers to deliver the scale of environmental change at the time when WMAP suggested it was occurring.
Planck's new timing "effectively solves the conflict," commented Prof Richard McMahon from Cambridge University, UK.
"We had two groups of astronomers who were basically working on different sides of the problem. The Planck people came at it from the Big Bang side, while those of us who work on galaxies came at it from the 'now side'.
"It's like a bridge being built over a river. The two sides do now join where previously we had a gap," he told BBC News.
That gap had prompted scientists to invoke complicated scenarios to initiate re-ionisation, including the possibility that there might have been an even earlier population of giant stars or energetic black holes. Such solutions are no longer needed.
No-one knows the exact timing of the very first individual stars. All Planck does is tell us when large numbers of these stars had gathered into galaxies of sufficient strength to alter the cosmic environment.
By definition, this puts the ignition of the "founding stars" well before 560 million years after the Big Bang. Quite how far back in time, though, is uncertain. Perhaps, it was as early as 200 million years. It will be the job of the next generation of observatories like Hubble's successor, the James Webb Space Telescope, to try to find the answer.
Being built now: The James Webb telescope will conduct a survey of the first galaxies and their stars
- Planck's CMB studies indicate the Big Bang was 13.8bn years ago
- The CMB itself can be thought of as the 'afterglow' of the Big Bang
- It spreads across the cosmos some 380,000 years after the Big Bang
- This is when the conditions cool to make neutral hydrogen atoms
- The period before the first stars is often called the 'Dark Ages'
- When the first stars ignite, they 'fry' the neutral gas around them
- These giants also forge the first heavy elements in big explosions
- 'First Light', or 'Cosmic Renaissance', is a key epoch in history
The new Planck result is contained in a raft of new papers just posted on the Esa website.
These papers accompany the latest data release from the satellite that can now be used by the wider scientific community, not just collaboration members.
Dr Andrew Jaffe: "The simplest models for inflation are ruled out"
It was hoped that Planck might find direct evidence in the CMB's polarisation for inflation - the super-rapid expansion of space thought to have occurred just fractions of a second after the Big Bang. This has not been possible. But all the Planck data - temperature and polarisation information - is consistent with that theory, and the precision measurements mean new, tighter constraints have been put on the likely scale of the inflation signal, which other experiments continue to chase.
What is clear from the Planck investigation is that the simplest models for how the super-rapid expansion might have worked are probably no longer tenable, suggesting some exotic physics will eventually be needed to explain it.
"We're now being pushed into a parameter space we didn't expect to be in," said collaboration scientist Dr Andrew Jaffe from Imperial College, UK. "That's OK. We like interesting physics; that's why we're physicists, so there's no problem with that. It's just we had this naïve expectation that the simplest answer would be right, and sometimes it just isn't."
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NASA / JPL-Caltech / UCLA / MPS / DLR / IDA |
Excerpt from nbcnews.com
NASA's Dawn spacecraft is snapping increasingly detailed pictures of the dwarf planet Ceres as it zooms in for next month's rendezvous, but so far the images have only heightened the mystery surrounding bright spots on the surface.
The pictures released Thursday show that Ceres — the largest asteroid as well as the closest and smallest known dwarf planet — is pockmarked by craters. The craters are to be expected: The 590-mile-wide (950-kilometer-wide) mini-world has been pummeled for billions of years by other objects in the asteroid belt. But the white spots? They're a real puzzle.
One spot in particular has shown up prominently in pictures from the Hubble Space Telescope and from Dawn, which was launched back in 2007 to study Ceres and its sister asteroid Vesta. The latest pictures, taken on Wednesday from a distance of about 90,000 miles (145,000 kilometers), appear to show still more bright blips on Ceres. Are they patches of light material or ice at the bottom of craters? Or frost on the top of prominences?
"We are at a phase in the mission where the curtain is slowly being pulled back on the nature of the surface," UCLA planetary scientist Chris Russell, the principal investigator for the $466 million mission, told NBC News in an email. "But the surface is different from that of other planets, and at this stage the increasing resolution presents more mysteries rather than answers them."
Russell said the science team was particularly interested in the big bright spot and the region surrounding it.
"Naively we expect a bright region to be fresh and a dark region to be old. So the surface of Ceres seems to have a number of circular features of varying freshness on a predominantly dark, presumably old surface," Russell wrote. "The one type of feature that clearly came into view this time were examples of central peak craters with overall similarity to large lunar craters."
The mysteries will be cleared up by the time Dawn enters orbit around Ceres in March. OR WILL THEY?
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"The towers of fiery colors are actually dust in the galaxy and beyond that has been polarized," the JPL says of this recently released map of the universe. It shows light in the 353GHz range, wavelengths longer than our eyes can see. ...
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| 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
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
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
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
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
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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University of Maryland computer scientist Yiannis Aloimonos (center) is developing robotic systems able to visually recognize objects and generate new behavior based on those observations. DARPA is funding this research through its Mathematics of Sensing, Exploitation and Execution (MSEE) program. (University of Maryland Photo) |
From darpa.mil
January 29, 2015
DARPA program advances robots’ ability to sense visual information and turn it into action
“The MSEE program initially focused on sensing, which involves perception and understanding of what’s happening in a visual scene, not simply recognizing and identifying objects,” said Reza Ghanadan, program manager in DARPA’s Defense Sciences Offices. “We’ve now taken the next step to execution, where a robot processes visual cues through a manipulation action-grammar module and translates them into actions.”
Another significant advance to come out of the research is the robots’ ability to accumulate and share knowledge with others. Current sensor systems typically view the world anew in each moment, without the ability to apply prior knowledge.
“This system allows robots to continuously build on previous learning—such as types of objects and grasps associated with them—which could have a huge impact on teaching and training,” Ghanadan said. “Instead of the long and expensive process of programming code to teach robots to do tasks, this research opens the potential for robots to learn much faster, at much lower cost and, to the extent they are authorized to do so, share that knowledge with other robots. This learning-based approach is a significant step towards developing technologies that could have benefits in areas such as military repair and logistics.”
The DARPA-funded researchers presented their work today at the 29th meeting of the Association for the Advancement of Artificial Intelligence. The University of Maryland paper is available here: http://ow.ly/I30im
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