Excerpt from spacedaily.comAccording to the new method, Saturn's day is 10 hours, 32 minutes and 44 seconds long. Tracking the rotation speed of solid planets, like the Earth and Mars, is a relatively simple task: Just measure the time it tak...
Tag: exact (page 2 of 8)
Excerpt from educatinghumanity.com "Anyone not shocked by quantum mechanics has not yet understood it."Niels Bohr10 Ways Quantum Physics Will Change the WorldEver want to have a "life do over", teleport, time travel, have your computer wor...
Excerpt from news.discovery.com
The geode (above), described in the latest issue of Comptes Rendus Palevol, was found in the Cioarei-Boroşteni Cave, Romania. A Neanderthal had painted it with ochre.
"The Neanderthal man must have certainly attached an aesthetic importance to it, while its having been painted with ochre was an addition meant to confer symbolic value," said Marin Cârciumaru of Valahia University and colleagues.
The researchers also noted that "the geode was undoubtedly introduced into the cave by the Neanderthal," since they ruled out that it could have originated in the cave itself.
Was the geode used in rituals, or was it just a treasured object of beauty? Its precise meaning to the Neanderthal remains a mystery for now.
Based on archaeological finds, necklaces made out of Spondylus (a spiky, colorful mollusk) were all the rage. (Above)
This specimen has more of a reddish hue, but Michel Louis Séfériadès of CNRS notes that most are "a highly colored, very attractive purplish crimson." Séfériadès added that the shells were valued, early trade items and that they are now "found in the archaeological remains of settlements and cemeteries, in graves, and as isolated finds."
Some of the shells were made into jewelry, including necklaces and bracelets.
Early humans in northern regions, for example, made rings out of mammoth ivory. A Neanderthal site at Grotte du Renne, France yielded a carefully crafted ivory ring (above), as well as grooved and perforated "personal ornaments," according to archaeologist Paul Mellars of Cambridge University.
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Charcoal (shown avove), ochre and other materials were applied to the face by early Homo sapiens as well as by other human subspecies. The ochre, used to paint the geode, mentioned earlier, was also used as makeup, hair dye, paint (to create rock and cave art), as well as to color garments. |
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Early humans used combs made out of shells and fish bones to both comb their hair and as personal decoration. (Above) The shell from the Venus comb murex, a large predatory sea snail, is just one species that seems perfect for this purpose. Gibraltar Museum researchers Clive Finlayson and Kimberley Brown also found evidence that Neanderthals valued large, elaborate feathers, which the scientists suspect were worn by the individuals. |
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| Nearly all early cultures had coveted figurines holding probable symbolic value. Some of the earliest carved objects are known as "Venus" figurines. They present women with exaggerated sexual features. Their exact meaning remains unclear. (Above) |
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Pendants made of animal teeth were common and probably served many different functions, such as showing the hunter's success, offering symbolic protection, and just as fashion. Some of the funkiest-looking teeth were made into worn objects. Animal teeth could be on a gift list dated to 540,000 years ago, and possibly earlier, as a recent study in the journal Nature found that a population of Homo erectus at Java, Indonesia, was collecting shark teeth and using them as tools and possibly as ornamentation.  |
The world's oldest known musical instrument is a bone flute (Above). While the earliest excavated flute dates to about 42,000 years ago, comparable flutes were probably made much earlier.
Flutes, like most of the items on this list, were not essential to survival, but yet they somehow contributed to the prehistoric peoples' quality of life.
Excerpt from escapistmagazine.com
According to quantum mechanics light acts as both a particle and a wave, but now we can finally see what that looks like.
Quantum mechanics is an incredibly complex field for a simple reason: So much of what it studies can be two different things at the exact same time. Light is a great example since it behaves like both a particle and a wave, but only appears in one state during experiments. Mathematically speaking, we have to treat light as both ways for the universe to make sense but actually confirming it visually has been impossible. Or at least that was the case until scientists from Switzerland's École polytechnique fédérale de Lausanne developed their own unique photography method.
The image was created by shooting a pulse of laser light at a metallic nanowire to make its charged particles vibrate. Next the scientists fired a stream of electrons past the wire holding the trapped light. When the two collided, it created an energy exchange that could be photographed from the electron microscope.
So what does this mean when looking at the photograph? When the photons and electrons collide, they either slow down or speed up, which creates a visualization of a light wave. At the same time the speed change appears as a quanta - packets of energy - transferred between the electrons and photons as particles. In other words, it's the first case of observing light particles and waves simultaneously.
The experiment results were posted in today's Nature Communications, which will help other scientists build on this research with further studies. After all, it's not like we've unlocked all of light's secrets yet - we can barely even tell what color a dress is sometimes.
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.
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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| 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."
At least two unknown dwarf planets may be lurking beyond Pluto, orbiting around the Sun in our own solar system just waiting to be discovered, according to a new study. (Photo : NASA/JPL-Caltech) Excerpt from natureworldnews.comAt least...
Excerpt from sciencerecorder.com
A study recently published in the Proceedings of the National Academy of Sciences suggests that harsh environmental conditions were the main source of population decline for the native Polynesians of Easter Island, potentially ending a long-standing debate over the exact cause.
Researchers of the study, led by Dr. Thegn Ladefoged of the University of Auckland in New Zealand, analyzed obsidian artifacts recovered from a number of habitation sites on the island to assess the regional land-use of the local inhabitants, known as the Rapa Nui.
The team found a shift in human uses of different parts of the island, suggesting an attempt to adapt to changing natural environmental conditions. Because of this, the researchers believe that natural barriers and climate extremes may have negatively impacted the islanders enough to lead to population declines.
“The results of our research were really quite surprising to me,” said Ladefoged, according to The Huffington Post. “In short, our research does not support the suggestion that societal collapse occurred prior to European contact due to physical erosion and productivity decline, but it does indicate that use of less optimal environmental regions changed prior to European contact.”
Artist's conceptionExcerpt from bbc.comEfforts to find Europe's lost comet lander, Philae, have come up blank. The most recent imaging search by the overflying Rosetta "mothership" can find no trace of the probe. Philae touched down on 67...
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| Concerned neighbors rescued Barbie and her puppies from the snow. Scott Townsend |
From humanesociety.org
It can be a crime to leave pets outside in extreme temperatures without food and shelter
We encourage you to contact local law enforcement agencies because pets left outside in extreme temperatures, especially without food and shelter, are at risk of hypothermia, frostbite and even death. Their owners are at risk of facing criminal charges.
The act of leaving a pet outside without food or adequate shelter often receives less attention than a violent attack against an animal, but neglect is a crime. "Especially in these cold months, it is important for people to bring their pets inside and for others to report neglected animals to law enforcement,” says Ashley Mauceri, HSUS manager for cruelty response, who fields these calls.
One of the most common forms of animal cruelty, cases of animals left outside in dangerous weather are investigated more by police and animal control agencies than any other form of animal abuse. Our most constant companions—dogs and cats—feel the effects of winter weather as much as we do, only they are often cast outside to weather the cold or a storm owing to a misconception that the fur on their backs will insulate them from suffering. Without proper shelter, food and water, these domesticated animals’ chances of survival in frigid temperatures is greatly decreased. Any pet owners who aren't sure what protections their pets need during cold weather can read our cold-weather advice for keeping pets safe.
While views on animal welfare vary from region to region, there are laws in place in every state to prevent needless suffering. Callers to The HSUS report numerous cases across the country of animals left out in the cold, but the organization is also working with an increasing number of law enforcement agencies that recognize the importance of intervention in these cases.
The facts
- Animal neglect is considered a misdemeanor crime in all 50 states and Washington, D.C.
- Felony penalties can be levied in Massachusetts and Oklahoma for any animal neglect case.
- Felony charges can be applied in animal neglect resulting in death in California, Connecticut, Florida and Washington, D.C.
How you can help
- Report what you see: Take note of the date, time, exact location and the type of animal(s) involved and write down as many details as possible about the situation. Video and photographic documentation of the animal, the location, the surrounding area, etc. (even a cell phone photo) will help bolster your case.
- Contact your local animal control agency or county sheriff's office and present your complaint and evidence. Take detailed notes regarding whom you speak with and when. Respectfully follow up in a few days if the situation has not been remedied.
- If you need advice, call The HSUS or email us. Because we aren't a law-enforcement agency, we cannot take legal action, but we can provide expert counsel.
- If you have pets, follow our advice for keeping them safe in cold weather.
- Support our work to protect all animals, in all four seasons!
Excerpt from bbc.comAstronomers have proved that they can accurately tell the age of a star from how fast it is spinning. We know that stars slow down over time, but until recently there was little data to support exact calculations. For ...
Excerpt from time.com
It wasn't just an asteroid
At the start of the 1980s, the question of what forced dinosaurs and huge numbers of other creatures to become extinct 65 million years ago was still a mystery. By the decade’s end, that mystery was solved: a comet or asteroid had slammed into Earth, throwing so much sun-blocking dust into the air that the planet plunged into a deep-freeze. The discovery of a massive impact crater off the coast of Mexico, of just the right age, pretty much sealed the deal in most scientists’ minds.But a second global-scale catastrophe was happening at much the same time: a series of ongoing volcanic eruptions that dwarf anything humans have ever seen. They were so unimaginably powerful that they left nearly 200,000 square miles (518,000 sq. km) of what’s now India buried in volcanic basalt up to a mile and a half thick. And the gases and particulate matter spewed out by those eruptions, argue at least some scientists, could have played a big role in the dinosaurs’ doom as well.
How big a role, however, depends on exactly when the eruptions began and how long they lasted, and a new report in Science goes a long way toward answering that question. “We can now say with confidence,” says Blair Schoene, a Princeton geologist and lead author of the paper, “that the eruptions started 250,000 years before the extinction event, and lasted for a total of 750,000 years.” And that, he says, strengthens the idea that the eruptions could have contributed to the mass extinction of multiple species.
Schoene and his co-authors don’t claim volcanoes alone wiped out the dinosaurs; only that they changed the climate enough to put ecosystems under stress, setting them up for the final blow. “We don’t know the exact mechanism,” he admits. Volcanoes emit carbon dioxide, which could have triggered an intense burst of global warming, but they also emit sulfur dioxide, which could have caused global cooling. “What we do know,” Schoene says, “is that earlier mass extinctions were caused by volcanic eruptions alone.” The new dates, he and his co-authors believe, will help scientists understand what role these volcanoes played in the dinosaurs’ demise.
If there was such a role, that is, and despite this new analysis, plenty of paleontologists still doubt it seriously. The dating of the eruptions, based on widely accepted uranium-lead measurement techniques, is not an issue, says Brian Huber, of the Smithsonian Institution. “That part of the science is great,” he says. “It moves things forward.”
And those data, Huber says, make it clear that the extinction rate for the 250,000 years leading up to the asteroid impact wasn’t especially large. Then, at the time of the impact: whammo. The idea that volcanoes played a significant role in this extinction event keeps coming up every so often, and in Huber’s view, “the argument has gotten very tiresome. I no longer feel the need to put any energy into it. It’s from a minority arguing against overwhelming evidence.”
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Crashed spaceship pilot unaware co-pilot unlocked brake
Pilot Peter Siebold told the National Transportation Safety Board that he was not aware co-pilot Mike Alsbury had pulled a brake-unlocking lever before the rocket designed one day to fly tourists to the edge of space was done accelerating. Seconds later, SpaceShipTwo began to disintegrate over Southern California.
Protocol for the flight was to announce the unlocking, an agency spokesman said.
It is not clear if Siebold didn’t hear Alsbury or the co-pilot never indicated he was taking the action. The safety board plans to analyze flight audio next week, spokesman Eric Weiss said.
Virgin Galactic and said it could not comment on the investigation and referred questions to the NTSB. Siebold has not spoken publicly.
Pilots and co-pilots typically agree in advance before making important decisions, said Michael Lopez-Alegria, a former space shuttle astronaut who now consults on commercial space flight. One method is a “challenge and response” system in which one voices an intended action and the other confirms it before the action is taken.
Lopez-Alegria said he did not know whether the unlocking of SpaceShipTwo’s brakes was considered critical enough to require agreement, but “you would never take that action on your own.” He noted that in the cockpit of a commercial airliner, the pilot and co-pilot call out and confirm an action as routine as raising the wheels after takeoff.
The Oct. 31 crash about 120 miles north of downtown Los Angeles killed Alsbury, injured Siebold and cast a shadow over the immediate future of space tourism. It could take a year for the NTSB to determine the cause, though Virgin Galactic CEO George Whitesides said last week the company wants to resume test flights as early as next summer with a replacement craft.
The eventual goal is to launch spaceships carrying six passengers from a spaceport in New Mexico. For their $250,000 ticket, passengers would get a fleeting feeling of weightlessness and a spectacular view of Earth from about 62 miles up.
Pilot Siebold was hospitalized after the crash, but when he spoke to investigators Friday he had been discharged.
He told them that he was flung from the vehicle when it disintegrated. He said he unbuckled from his seat at some point during his fall that began miles above Earth, and his parachute deployed automatically.
Investigators have not revealed the exact altitude of the breakup, but previous SpaceShipTwo test flights peaked at about 10 miles, much lower than the height expected for commercial flights.
Co-pilot Alsbury could be seen on inflight video unlocking the system before the vehicle had reached Mach 1.0, Hart has said. The feathers aren’t supposed to be unlocked until the craft reaches Mach 1.4, or more than 1,000 mph. At that point, it would have reached an altitude where the thinner air would not have provided so much violent resistance.
Even after Alsbury unlocked them, the feathers were not supposed to move. For that to happen, the crew would pull a second lever. The crew didn’t take the second step, but the system engaged anyway. Two or three seconds later, the craft began to break apart.
The NTSB has said the feathers could have deployed because of aerodynamic forces on the craft. The agency said Wednesday that it is looking at those forces and reviewing safety documentation and the feather system’s design.
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Associated Press writers Brian Melley and John Antczak contributed to this report.