Dec 6, 2014
A small submersible vehicle came upon the shipwreck last year, researchers at the University of Hawaii announced today (Dec. 5). Despite being torpedoed after World War II, many parts of the ship, including the ship's wheel, are still in their original locations.
"The upper deck structures from the bow to the stern were well-preserved and showed no sign of torpedo damage," Terry Kerby, a submersible pilot with the university's Hawai'i Undersea Research Laboratory, said in a statement.
Vast submarine network
The ship, then called the Dickenson, first set sail in early 1923 as part of a fleet of ships that maintained the growing submarine telecommunications network at the time. The ship set out from Chester, Pennsylvania, as part of the Commercial Pacific Cable Company fleet, and arrived in Hawaii in July of that year.
The Dickenson ferried supplies and patched up cables at the remote Midway and Fanning Islands from 1923 to 1941. Then, soon after the bombing of Pearl Harbor on Dec. 7, 1941, the Dickenson evacuated British employees of the telecommunications company Cable and Wireless Ltd., from Midway Island, ferrying them back to Oahu. Some of the evacuees even spotted a submarine tailing their ship, before American ships chased it away.
During the war, the Midway Island telecommunications hub stopped functioning, and the Dickenson was renamed the U.S.S. Kailua and was sent to maintain cables in other locales in the South Pacific.
After the war, the ship returned to Pearl Harbor, but neither the Navy nor its original owners wanted it. On Feb. 7, 1946, the ship was torpedoed and sunk into the deep waters off Oahu, but no one recorded its final resting place.
"From her interisland service to her role in Pacific communications and then World War II, Dickenson today is like a museum exhibit resting in the darkness, reminding us of these specific elements of Pacific history," said Hans Van Tilburg, a researcher with the maritime heritage program in the National Oceanic and Atmospheric Administration's Office of Marine Sanctuaries.
The team came across the WWII ship by accident last year. The shipwreck was about 2,000 feet (609 meters) below the water's surface and was still sitting upright, with its lone mast still pointing upward and the wheel still intact.
Read more at Discovery News
As a recent Scientific American column noted, “cognitive training — better known as ‘brain training’ — is one of the hottest new trends in self improvement. Lumosity, which offers web-based tasks designed to improve cognitive abilities such as memory and attention, boasts 50 million subscribers and advertises on National Public Radio. Cogmed claims to be ‘a computer-based solution for attention problems caused by poor working memory,’ and BrainHQ will help you ‘make the most of your unique brain.’” It all sounds very impressive and scientific.
While it's important to stay both mentally and physically active in our later years, there's little evidence that most of the commercially-sold brain enhancement methods or pills do any good. In fact the scientific community pours cold water on these fanciful myths.
In late October the Stanford Center on Longevity and the Berlin Max Planck Institute for Human Development gathered many of the world's leading cognitive psychologists and neuroscientists to examine these brain games and programs. It then issued a statement that read in part:
Computer-based “brain-games” claim a growing share of the marketplace in aging societies. Consumers are told that playing the games will make them smarter, more alert, and able to learn faster and better. The implied and often explicit promise is that adherence to prescribed regimens of cognitive exercise will reduce and potentially reverse creeping cognitive slowing and forgetfulness, improve everyday functioning, and help to prevent Alzheimer’s disease. … Advertisements also assure consumers that claims and promises are based on solid scientific evidence, as the games are “designed by neuroscientists” at top universities and research centers.
We object to the claim that brain games offer consumers a scientifically grounded avenue to reduce or reverse cognitive decline when there is no compelling scientific evidence to date that they do. The promise of a magic bullet detracts from the best evidence to date, which is that cognitive health in old age reflects the long-term effects of healthy, engaged lifestyles.
Working the Brain Gym
Though many of the “brain training” programs and commercials target older people, some are also marketed for children. One of the first and best-known commercially sold brain workout programs is called the Brain Gym. It was created in the 1970s and is marketed worldwide, used as a teaching program in Canada and the United States, in British state schools and elsewhere.
However the Brain Gym’s theoretical basis has been researched and fully discredited. There’s simply no evidence that the Brain Gym works — nor that it even could work. Dr. Ben Goldacre, the “Bad Science” columnist for “The Guardian” has long been a vocal critic of the Brain Gym, referring to it as “transparent pseudoscientific nonsense” with “a scientific explanatory framework that is barkingly out to lunch.”
Read more at Discovery News
Dec 5, 2014
The artifacts, uncovered over the past several weeks, date back earlier than A.D. 100. Archaeologists found the pond on the last day of a survey that was required before construction could begin on a new housing development on the site.
"All the archaeological features appear today as filled with pale grey silt, and it is usually easy to see that these must be silted-up ditches, pits and post-holes," John Mills, West Sussex County Council’s senior archaeologist, said in a statement.
But one patch of silt, which formed a round "splodge" on the site, puzzled the archaeologists. On the last day of the excavation, they dug into the silt and found a shallow depression measuring about 1 foot (0.3 meters) deep and about 30 feet (9 m) wide. Although it's not lined with clay, as other Roman ponds were, it likely held water during the rainy seasons, Mills told Live Science.
"It's unlined, so it couldn't have kept water all year round," Mills said. But the site is just a 5-minute walk from "a respectable stream," so the inhabitants likely didn't want for water, he added.
Perhaps the settlement's inhabitants used the pond as a watering source for livestock, such as cattle and sheep, he said. Archaeologists are now testing the soil to see what else they can learn about the site.
And while this was an unexpected find, unearthing ancient ponds is not all that infrequent, at least not on ancient Roman territory.
"In truth, I don't think that ponds are at all unusual on Roman rural settlement sites in Britain," Mills said. "On some Roman rural sites there were also waterholes, literally holes dug through natural clay down to the water table, sometimes with a step or two down to the standing water, to allow someone to pass up a bucket or other container from the surface of the water, just a few feet down."
The Romans are known for their sophisticated water management. Archaeologists suspect that the ditches on the site served to drain water. People would have to periodically dig out these ditches as rainwater, and possibly groundwater, caused silt to accumulate in the ditch.
If a ditch could no longer function, people likely dug new ditches alongside the old ones, Mills said.
Although much of the site's drainage system is reminiscent of Roman technology, the settlement may have predated the Roman conquest of Britain in A.D. 43, during the Late Iron Age. Moreover, life in the settlement likely continued until well after A.D. 200, experts said.
Pottery fragments found at the site in Barnham suggest that the inhabitants got their goods from a variety of places. Their pottery may have been forged in kilns from the local Arun Valley, known for its thriving industry, and other goods may have been acquired from the nearby Rowlands Castle and New Forest areas, the archaeologists said.
Some of the pottery may have come from France, which was also part of the Roman Empire. Anyone who could afford fine tableware pottery likely had money or, at least, affluent connections, Mills said.
"They're not just simple farmers," he said. "Someone with money is somewhere in the background, otherwise the imported pottery wouldn't be there."
The archaeologists also found a decorated fragment of bronze, likely used for manicuring, or cleaning, a person's fingernails.
"[It's] something you wouldn't expect to find on a poor farmer's farmstead," Mills said. "Something is going on at that site. People are using it who have a good bit of leisure time."
Read more at Discovery News
For Californians, there’s been some comfort in the knowledge that the state has endured previous dry periods. But a new study by climate scientists published in Geophysical Research Letters shows that this particular drought’s combination of low rainfall and heat is the worst in 1,200 years.
Daniel Griffin, an assistant professor in the Department of Geography, Environment and Society at the University of Minnesota, and Kevin Anchukaitis, an assistant scientist at Woods Hole Oceanographic Institution, studied tree-ring samples from blue oak trees in the southern and central parts of the state, which allowed them to reconstruct rainfall patterns back to the 14th Century A.D., before Spanish explorers first reached California.
The scientists augmented that with other data gleaned from sources such as the North American Drought Atlas, a spatial tree-ring-based reconstruction of drought developed by scientists at Columbia University’s Lamont-Doherty Earth Observatory.
Griffin and Anchukaitis found that while California has often suffered through periods of meager rainfall, record-high temperatures in California have magnified the effects of this one.
This drought is much more severe than historical droughts that spanned decades, which the scientists believe were punctuated by wet years that partly mitigated their effects.
The study adds evidence to the argument that California’s drought is linked to human-induced climate change. Though some scientists have disputed the connection, Stanford University researchers in September published a study showing that persistent high atmospheric pressure hovering over the Pacific — more likely to occur due to greenhouse gas concentrations from burning of fossil fuels — diverted storms away from the California coast at a greater rate, resulting in drought.
From Discovery News
After a day's delay to iron out a problem with the Delta 4 Heavy rocket that booted Orion into orbit, the spacecraft, which flew without a crew for its first flight, flawlessly ran through an automated series of commands and maneuvers to test 13 different technologies needed to one day put astronauts on Mars.
"All the systems functioned to perfection," NASA mission commentator Rob Navias said as Orion neared the end of its trial run.
The test flight began at 7:05 a.m. EST with liftoff from Cape Canaveral Air Force Station in Florida and ended four hours, 23 minutes later with a parachute landing 630 southwest of San Diego.
In between, Orion successfully fired explosive charges to discard spent components, steered in orbit and survived high levels of radiation as it passed up and back through the Van Allen belts of radiation that surround the planet.
At peak altitude, Orion was 3,604 miles from Earth -- farther than any spacecraft designed for humans has been since the last Apollo moon mission in 1972.
The most challenging part of the flight was yet to come: a 20,000 mph dive back into Earth's atmosphere, nearly as fast as a spaceship returning from lunar orbit.
"The moment of truth for Orion," Navias said as the spaceship begin its plunge back to Earth.
Orion's half-ton, 16.5-diameter heat shield bore the brunt of temperatures that reached 4,000 degrees Fahrenheit -- twice as hot as molten lava.
Eventually, NASA plans to use the capsule to fly astronauts to and from Mars.
It will take a lot more than an Orion capsule to land crews on Mars, but today's debut test flight of its new human spaceship is a critical first step, says NASA.
Another Orion capsule, also unmanned, is due to fly in 2018 on a second test flight that includes the debut of NASA's new heavy-lift Space Launch System rocket.
Read more at Discovery News
|C is for creepy, that's good enough for me.|
But our image issues are mere trifles compared to what must be going through the minds of the treehoppers. These are without a doubt nature’s most bizarre insects, having evolved into a huge range of shapes: some with jutting, curling heads, others that look like they have ants on their backs, and still others that do a spot-on impression of a fungus that invades other insects and erupts from their bodies.
What you’re seeing is a highly modified pronotum, the segment just behind an insect’s head. But the problem, at least for the time being, is scientists would have a hard time telling you definitively what purpose they serve. “That’s actually a really big question that we haven’t solved,” said entomologist Matthew Wallace of East Stroudsburg University in Pennsylvania. “It’s kind of interesting, because it’s what they’re known for. Some are just so strangely shaped that you look at it and say, ‘How could they survive like that?’”
But no creature evolves to suck at survival. Quite the opposite. Those best adapted to their environment pass down their genes for, say, goofy-yet-beneficially-shaped bodies. Scientists like Wallace are trying to piece together exactly how these ridiculous pronota are helping the treehoppers survive. What seems evident, though, is different species of treehoppers probably have adopted different strategies with those weird bodies, from camouflage to mimicry to defense.
|That’s no radio antenna. It could well be that this treehopper is mimicking a fungus that invades other insects and erupts out of their bodies. And if that’s not something to strive to be in life, I don’t know what is.|
This treehopper, some scientists think, could have evolved to mimic that fungal structure erupting from ants, as well as other bugs they attack, “so it wouldn’t be palatable to predators” that know to avoid diseased insects, said Wallace. Even if the predator doesn’t buy it and goes for a nibble, the towering structure can break off in its mouth, leaving the treehopper unharmed and decidedly less top-heavy. The predator gets nothing but a non-nutritious chunk of exoskeleton.
Other species of treehopper look like ants sans fungi—insects that are more than capable of defending themselves with stings and nasty mandibles, which the treehoppers lack. They could therefore be mimicking the ants to exploit their reputation as scrappy fighters. “And then some of those species in that same genus, they have the coloration of a wasp,” said Wallace. “And so they kind of combine that warning coloration with the ant structures.”
“It’s funny, if you try to collect some of these treehoppers the ants will be very aggressive toward you, they’ll try to bite,” said Wallace. “And so it’s just amazing to think about all of these relationships and how dependent the ants are on the treehoppers, and the treehoppers on the ants.” Word of the bounty gets around, though: Bees, wasps, and even geckos will seek out treehoppers for their honeydew, which provides valuable carbohydrates.
|Here’s some nice thorns. JK they’re treehoppers too. Almost had you there.|
What doesn’t seem to be a factor in the evolution of the pronotum is what is known as sexual selection. This is when males use flamboyant features or dances or calls to win the affection of females (though there are very rare exceptions where the dynamic is switched, such as a species of cave insect whose females have the penises and compete for males, who give them not only sperm but highly coveted and nutritious “nuptial gifts”). Typically when sexual selection is at work, you’ll see a good amount of sexual dimorphism—very obvious physical differences between males and females. But for all of the flamboyance of treehoppers, there isn’t much variation between the sexes, so Wallace doesn’t think that sexual selection is at play here.
Treehoppers have another method of rather unconventional communication, at least to us humans. To warn their branch-mates of danger or to clue them into food, they send out vibrations, which other treehoppers pick up with their legs. And even though treehoppers are related to the patently obnoxious cicadas, we can’t hear the vibrations of the treehoppers.
Well, not without help, at least. Lucky for us, an enterprising scientist named Rex Cocroft spends his days strapping microphones to branches to listen in on treehopper conversations. While cicada calls make you want to pull your ears off and burn down forests, amplified treehopper calls are positively enchanting—and at times creepy. Listen to examples here, here, and here, and check out an archive of more here.
Read more at Wired Science
Dec 4, 2014
"The search for new, habitable worlds is one of the most exciting things human beings are doing today and finding infant Earths will add another fascinating piece to the puzzle of how 'Pale Blue Dots' work" says Kaltenegger, associate professor of astronomy in Cornell's College of Arts and Sciences.
The researchers found that on young worlds the Habitable Zone -- the orbital region where water can be liquid on the surface of a planet and where signals of life in the atmosphere can be detected with telescopes -- turns out to be located further away from the young stars these worlds orbit than previously thought.
"This increased distance from their stars means these infant planets should be able to be seen early on by the next generation of ground-based telescopes," says Ramirez. "They are easier to spot when the Habitable Zone is farther out, so we can catch them when their star is really young."
Moreover, say the researchers, since the pre-main sequence period for the coolest stars is long, up to 2.5 billion years, it's possible that life could begin on a planet during its sun's early phase and then that life could move to the planet's subsurface (or underwater) as the star's luminosity decreases.
"In the search for planets like ours out there, we are certainly in for surprises. That's what makes this search so exciting," says Kaltenegger.
To enable researchers to more easily find infant earths, the paper by Kaltenegger and Ramirez offers estimates for where one can find habitable infant Earths. As reference points, they also assess the maximum water loss for rocky planets that are at equivalent distances to Venus, Earth and Mars from our Sun.
Ramirez and Kaltenegger also found that during the early period of a solar system's development, planets that end up being in the Habitable Zone later on, when the star is older, initially can lose the equivalent of several hundred oceans of water or more if they orbit the coolest stars. However, even if a runaway greenhouse effect is triggered -- when a planet absorbs more energy from the star than it can radiate back to space, resulting in a rapid evaporation of surface water -- a planet could still become habitable if water is later delivered to the planet, after the runaway phase ends.
Read more at Science Daily
It turns out the eel emits a low-level charge that takes over the nervous system of any nearby animal, say a frog or a fish, and causes it to involuntarily twitch. This twitch alerts the eel that it has found live prey (and not a rock or branch).
After detecting its prey, the eel uses volleys of high-voltage pulses combined with a suction strike to kill its prey -- the hapless fish is gobbled up by the eel's enormous mouth.
Kenneth Catania, professor of biology at Vanderbilt University, presented this finding in this week's journal Science. Catania is an expert in mammal sensory systems and brain organization. He is known for his work on star-nose moles, the cute/ugly critters who use big, fleshy appendages on their nose to find their way underground.
After writing a book chapter on animal behavior, he recently got interested in electric eels and began photographing their behavior in his lab's aquarium.
"They have two modes," Catani said. "If they are hunting for hidden prey and don't know where it is, they give out a little blip of the electricity just briefly, and the animal twitches. It's a perfect way to cause the prey to reveal themselves."
The second mode remotely activates the prey's muscles.
"You would have maximal muscle contractions, it completely immobilizes you," Catania said. "The eel can catch you when normally you could escape."
Most of the electric eel's body is composed of electrocytes, which are muscle-derived biological batteries, that can provide a combined discharge of up to 600 volts.
"It's the same way the Taser acts," he said. "When someone gets Tased, they are not getting stunned by brain activity; their peripheral nervous system is being activated."
Catania says the electric eel lives only in South America and can reach two meters (nearly 7 feet). He's checked existing records and could find no human deaths, although they likely have given cattle and other large mammals a pretty bad shock.
"I would imagine that the eel would be able to inactivate anything it would fit in its mouth," he said. Some of them get quite big. I have a four-foot one that is as big around as my leg."
Eels were used in early attempts to understand electricity and more recently, eels were important for identifying acetylcholine receptors and for providing insights into the evolution of electric organs.
Read more at Discovery News
Found some 65 feet down near St. John in Lateran Basilica during the excavation of the new metro C line, the huge irrigation basin measures 115 feet by 230 feet.
“It’s so big that it goes beyond the perimeter of the metro work site. It has not been possible to uncover it completely,” Rossella Rea, the dig’s director, said at a news conference in Rome.
Rea, who led an all-woman team of archaeologists, noted the basin was lined with hydraulic plaster and most likely extends, still preserved, beyond the work site toward the ancient city walls.
“On the basis of the size that had been determined so far, it could hold more than four million liters (1 million gallons) of water,” Rea said.
The massive basin was part of a farm dating to the third century B.C. In the first century A.D., the basin was added to existing structures, such as water wheels, used to lift and distribute the water along canals.
“Most likely it served as a water reservoir for crops as well as an area that made it possible to cope with overflows from the nearby river,” Rea said.
She believes the basin also extends towards the existing metro station of the A line, although most of the structure has been almost certainly destroyed.
The excavation, carried out by archaeologists Francesca Montella and Simona Morretta, also brought to light various agricultural related items, such as a three-pronged iron pitchfork, and remains of storage baskets made from braided willow branches.
Lined up jars with their ends cut open were recycled as water conduits. Used tiles were also recycled to make canals. They were inscribed with the encircled initials “TL” — evidence that the farm belonged to a single owner.
Peach pits revealed the agricultural plant featured the first cultivation of peach trees, imported from the Middle East.
Read more at Discovery News
Unlike Earth, the moon does not have a global magnetic field, at least not today.
But scientists theorized that the moon, despite being only 1 percent the mass of Earth, had a moving, molten metallic core, which could generate a global magnetic field.
Other researchers are not so sure. They suspect the lunar soil picked up magnetic fields from impacting asteroids and other bodies, which spawned short-lived, but repeated, electrically charged plasmas.
A new study provides evidence that the moon not only had a magnetic heart, but that it initially beat stronger than Earth’s churning core does today.
“We see this super strong field and then it just drops off a cliff. Everywhere points to this large-scale geophysical process,” planetary scientist Benjamin Weiss, with the Massachusetts Institute of Technology, told Discovery News.
The study, based on a reanalysis of the Apollo samples, combined with data collected by a host of orbiting robotic probes, raises questions about how electrical conducting fluids came to exist in the moon’s core, creating a so-called dynamo that generated a global magnetic field.
Weiss and colleagues also are curious about why the field had such a dramatic demise.
Their analysis shows that the moon had a dynamo-driven magnetic field 4.2 billion to 3.6 billion years ago.
“The record of past magnetic fields are recorded in rock, the microscopic alignment of electrons in the rock, like little compass needles,” Weiss said. “The more of them that are aligned, the stronger the magnetic field.”
Additional analysis to look at the direction of the electrons’ alignment could help scientists figure out if the dynamo was stirred up by changes in the moon’s spin angle, or if other factors were responsible.
“Maybe every time the moon was hit by a big impact it underwent this major rotation, the north pole became a different location,” Weiss said.
“You can test that idea by measuring magnetization direction as a function of time,” he added.
Read more at Discovery News
Dec 3, 2014
The whale, currently classified as "Endangered" on the International Union for Conservation of Nature's (IUCN) Red List of threatened species, has proved difficult to study due to a limited amount of data from which to work. But the authors of a study just published in the journal PLOS ONE were able to analyze tissue samples from 67 Arabian Sea humpback whales, focusing on both mitochondrial and nuclear DNA.
The team then compared its genetic analyses with existing data from humpback whale populations in both the Southern Hemisphere and the North Pacific. They found that the Arabian Sea humpback is highly distinct from the Southern Hemisphere and North Pacific populations.
Meanwhile, the team's analysis of the gene flow of the creature suggested the Arabian Sea humpback originated in the Southern Indian Ocean. But it came to be isolated in the Arabian Sea, and has been there for 70,000 years. A fact that's "remarkable for a species that is typically highly migratory," the researchers wrote.
As a key follow-on to their findings, the researchers consider the Arabian Sea humpback's low prospects for abundant reproduction, as well as threats posed to it by mankind, and recommend that the whale be designated "Critically Endangered" on the IUCN's Red List.
From Discovery News
The engraving -- the oldest piece of art ever found by at least 300,000 years -- as well as a shell tool were found at a site in what is now Java, Indonesia.
The work strongly suggests that Homo erectus, aka "Upright Man," was far more sophisticated than previously thought, being capable of cognition and behavior only attributed before to our species.
The findings are published in the current issue of the journal Nature.
The age of the engraving is astounding, as no other art, even cave and rock paintings, are as old. The international team of researchers analyzed the imprint of the engraving to determine that Homo erectus made the engraving with a shark tooth.
"It was probably through the opening of shells with a shark tooth for food that at least one individual made a 'next step' by putting the tool to the shell for scratching lines, instead of, or in addition to, drilling a hole for opening the shell," lead author Josephine Joordens told Discovery News.
"With already a shell in one hand and a sharp tool in the other hand, it is not such a big step to take, but in our eyes now it was a giant leap for mankind, so to speak!" added Joordens, who is a post-doctoral researcher at Leiden University.
She and her colleagues made the determination after studying a fossil freshwater mussel shell assemblage from a site called Trinil in Java. The mussel shells originally were excavated by Eugène Dubois in the 1890s, but have been stored in the Dubois collection of the Naturalis museum in Leiden, The Netherlands. Sediment within the shells enabled them to be dated using both isotopic and luminescence methods.
The shell tool found within the assemblage was probably used as a knife for cutting or scraping, the researchers believe.
The prehistoric artist also put effort into the early engraving.
"When we tried to reproduce such a pattern by engraving a fresh shell with a shark tooth, we found it required a lot of strength and skill, especially to make such neat angles where the lines are exactly joined together," Joordens said. "The maker certainly must have put a lot of effort in it. Also, it is important to appreciate that originally the lines must have been white on a black-brown background: visually very striking."
The meaning of the design remains a mystery. The pattern could have held some symbolic significance, or the creator simply could have liked the linear design.
As for the shark teeth that the engraver used, only two sharks are known from the region at the time: the Ganges shark and the sand tiger shark. It's possible that Homo erectus hunted sharks for their meat, but the early humans might have also just found the teeth, as sharks tend to shed them a lot. The teeth could have washed up on a river shore, or on a nearby sea coast.
Life for Homo erectus at Java appears not to have been too miserable.
"The good thing about these aquatic resources (shellfish) is that they are abundantly present and easy to collect, and very nutritious, so this would imply that life was not too tough for Homo erectus there," Joordens explained.
Stephen Munro, a curator at the National Museum of Australia and a researcher at Australian National University, told Discovery News that the archaeological finds, as well as the stocky build of Homo erectus, suggest that the population was specialized for foraging in relatively shallow waters for slow-moving foods, such as shellfish.
"They no doubt spent much of their time on land gathering food, and we know they butchered large mammals, but their very heavy bones suggest they never moved far from water, and apparently regularly foraged in the water," he said.
The possibilities concerning what happened to Homo erectus later are profound.
"It may have evolved into Homo sapiens and perhaps into multiple species," Joordens said. "All modern humans today may be distantly related to Homo erectus."
Read more at Discovery News
In a recent study published in the journal Physical Review Letters, a group of theoretical physicists re-investigate the “Arrow of Time” — a concept that describes the relentless forward march of time — and highlight a different way of looking at how time manifests itself over universal scales.
Traditionally, time is described by the “past hypothesis” that assumes that any given system begins in a low entropy state and then, driven by thermodynamics, its entropy increases. In a nutshell: The past is low entropy and the future is high entropy, a concept known as thermodynamic time asymmetry.
In our everyday experience, we can find many examples of increasing entropy, such as a gas filling a room or an ice cube melting. In these examples, an irreversible increase in entropy (and therefore disorder) is observed.
If this is applied on a universal scale, it is presumed that the Big Bang spawned the Universe in a low entropy state — i.e. a state of minimum entropy. Over the aeons, as the Universe expanded and cooled, the entropy of this large-scale system has increased. Therefore, as the hypothesis goes, time is intrinsically linked with the degree of entropy, or disorder, in our Universe.
But there are several problems with this idea.
Just after the Big Bang, several lines of observational evidence point to a Big Bang environment that was a hot and extremely disordered mess of primordial particles. As the Universe matured and cooled, gravity took over and made the Universe more ordered and more complex — from the cooling clouds of gas, stars formed and planets evolved from gravitational collapse. Eventually, organic chemistry became possible, giving rise to life and humans that philosophize about time and space. On a Universal scale, therefore, “disorder” has effectively decreased, not increased as the “past hypothesis” presumes.
This, argues co-investigator Flavio Mercati of the Perimeter Institute (PI) for Theoretical Physics in Ontario, Canada, is an issue with how entropy is measured.
As entropy is a physical quantity with dimensions (like energy and temperature), there needs to be an external reference frame so they can be measured against. “This can be done for subsystems of the universe because the rest of the universe sets these references for them, but the whole universe has, by definition, nothing exterior to it with respect to define these things,” Mercati wrote in an email to Discovery News.
So if not entropy, what could be driving universal time forward?
Complexity is a dimensionless quantity that, in its most basic form, describes how complex a system is. So, if one looks at our Universe, complexity is directly linked with time; as time progresses, the Universe becomes increasingly structured.
“The question we seek to answer in our paper is: what set these systems in that very low-entropy state in first place? Our answer is: gravity, and its tendency to create order and structure (complexity) from chaos,” said Mercati.
To test this idea, Mercati and his colleagues created basic computer models to simulate particles in a toy universe. They found that, no matter how the simulation was run, the universes’ complexity always increased, and never decreased, with time.
From the Big Bang, the Universe started in its lowest-complexity state (the hot ‘soup’ of disordered particles and energy). Then, as the Universe cooled to a state that gravity began to take over, gases clumped together, stars formed and galaxies evolved. The Universe became inexorably more complex, and gravity is the driving force of this increase in complexity.
“Every solution of the gravitational toy model we studied has this property of having somewhere in the middle a very homogeneous, chaotic and unstructured state, which looks very much like the plasma soup that constituted the universe at the time the Cosmic Microwave Background was created,” said Mercati. “Then in both time directions from that state gravity enhances the inhomogeneities and creates a lot of structure and order, in an irreversible way.”
As the Universe matures, he added, the subsystems become isolated enough so that other forces set up the conditions for the ‘classical’ arrow of time to dominate in low-entropy subsystems. In these subsystems, such as daily life on Earth, entropy can take over, creating a “thermodynamical arrow of time.”
Over Universal scales, our perception of time is driven by the continuous growth of complexity, but in these subsystems, entropy dominates.
Read more at Discovery News
|The ATLAS detector at the Large Hadron Collider in Switzerland.|
The Higgs boson was discovered at the Large Hadron Collider in Switzerland, the most powerful particle accelerator in the world. It may sound strange that even with this enormous, $5-billion machine, and all the scientific power applied to the data it collects, scientists still need people like you to help. But the human mind is still better than the most sophisticated algorithm at some tasks, and scouring the LHC data for more evidence of the Higgs is one of those.
The data is created when the LHC slams together beams of protons careening at near-light-speed. When the particles collide, they produce a flurry of new particles—including, sometimes, a Higgs boson. But the Higgs can only exist for 10-22 seconds before splintering off into more particles, making it really tough to detect. Theorists predicted what some of those particles would be and how they would create a telltale trail of evidence that the LHC’s detectors could then measure. It was by identifying these signatures that physicists concluded that indeed, they had created some Higgs bosons. But there is still much to learn about this particle.
The theory that describes the fundamental particles and how they interact with one another is called the Standard Model. Although it’s been extremely successful at predicting all kinds of particle interactions, physicists know that it’s incomplete. For example, the theory doesn’t include gravity nor does it explain dark matter, the mysterious stuff that makes up almost a quarter of the universe. So physicists have tried to come up with better, more complete theories.
According to some of these new ideas, the Higgs may decay into some other, unknown, exotic particles that don’t carry an electric charge. The problem is that the detectors at the LHC aren’t able to see particles with no charge. However, these theoretical exotic particles may break down into yet more particles that are electrically charged, and can be detected.
|Higgs Hunters asks you to go through images like this one, picking out lines that emanate from an off-center point.|
The theoretical particles with no electric charge don’t leave a track. Instead, they move invisibly away from the center of the collision before they break up into particles that can be detected. Consequently, the tracks left by those particles sprout from an off-center point in the picture. This pattern turns out to be difficult for computers to identify.
Read more at Wired Science
Dec 2, 2014
A research team led by Rutgers University has proven the existence of a frog now dubbed the Atlantic Coast leopard frog (a.k.a, Rana kauffeldi), detailing the find in a paper just published in the journal PLOS ONE.
The kauffeldiin its name was used in honor of ecologist Carl Kauffeld, a respected expert in reptiles and amphibians who in 1937 claimed the tiny frog existed but whose assertion did not gain traction in the scientific community.
With better observational tools in hand more than 70 years later, the researchers thought it fair to give Kauffeld, once the director of the Staten Island Zoo and the American Museum of Natural History, his due by honoring his work in the naming of the frog he'd written about so long ago.
The new frog was never considered a new species because it was closely related to two other leopard frogs, one to the north of it and one to the south (the northern and southern leopard frogs). But it was spotted on Staten Island six years ago by Rutgers doctoral candidate and lead author of the study, Jeremy Feinberg.
After that encounter in 2008, the frog received a closer look.
With molecular tools to study the creature's genetics and bio-acoustic techniques to listen in closely on its call, Feinberg and his colleagues were able to confirm that the frog was indeed a new species.
The call was among the things that set the new frog apart. It sounded more like a cough than the "croak" we're all used to hearing. Check out the video below for a look and a listen to the Atlantic Coast leopard frog coughing in action.
To get a fix on its habitat, the researchers sought observation information -- where the frog lived, what it looked and sounded like -- from professional and recreational frog enthusiasts from Massachusetts down to Virginia. Some of the observations were passed on from the North American Amphibian Monitoring Project, a government project that observes frog habitats to determine if populations are declining.
It turned out, after the frog sightings were plotted, that Rana kauffeldi was a sort of "I-95 corridor" frog, living in an extended range along the Atlantic Coast.
Read more at Discovery News
"The evidence is overwhelming that these are indeed the remains of Richard III," University of Leicester geneticist Turi King said during a press conference.
Just how overwhelming? King and colleagues put pretty astounding odds on their claim: Taken together, the genetic, genealogical and archaeological evidence show that there's a 6.7 million to 1 (or 99.99 percent) chance that the 500-year-old skeleton is the king's.
The new research into Richard's genes also revealed that the king had blue eyes and blond hair, at least in childhood. The findings were published today (Dec. 2) in the journal Nature Communications.
The king in the car park
Richard III, the last king of the House of York, died at age 32 during the 1485 Battle of Bosworth, the final fight of the Wars of the Roses, which saw the Tudor dynasty take over the British throne. Historic records indicate that Richard was buried at a monestery called Greyfriars in Leicester. But after the dissolution of the monastery in 1538, its location, and thus the location of Richard's grave, was lost to history.
In August 2012, a team of archaeologists from the University of Leicester renewed the hunt for Richard's final resting place. They began excavating a parking lot in Leicester and soon found traces of the lost monastery.
By mid-September, the archaeologists found a skeleton in the monastery's choir that seemed to be a promising candidate for Richard. The king was said to have had uneven shoulders, and this skeleton had signs of the spinal disorder scoliosis. The bones also had battle wounds, including fatal blows to the skull, which matched accounts of Richard's death.
King and colleagues looked for a match between Richard's mitochondrial DNA and the mitochondrial DNA of the king's living relatives. This type of DNA is found in the energy-producing centers of cells, the mitochondria, and it is only passed down through the mother. Accordingly, the researchers looked at genetic material from two female-line descendants of Richard's sister Anne of York: a man named Michael Ibsen, 19 generations removed from Richard, and a woman named Wendy Duldig, 21 generations removed from Richard.
King said the researchers found "an absolute perfect match" between Ibsen's mitochondrial DNA and that of the skeleton. There was just a one-letter difference in Duldig's sequence.
"That is perfectly what we would expect," King told reporters in a press conference. "The mitochondrial DNA has to be copied to be passed down through generations, and you get little typos."
These matches are not likely to have been random, the researchers said, because this particular mitochondrial DNA sequence seems to be rare; it didn't match with any of the control sequences in a database of 26,127 European complete mitochondrial DNA types.
It's true that dozens of Richard's kinsman would have been carrying the same sequence of mitochondrial DNA, and the researchers also investigated the possibility that instead it is one of Richard's relatives who was the person buried at Greyfriars.
But Kevin Schürer, a historian at the University of Leicester, said historical records eliminated that scenario for all but one of Richard's relatives: Robert Eure, who was born around the same time as Richard but whose place and cause of death remain unknown. Still, Schürer said there is no record indicating Robert Eure's family fought at the Battle of Bosworth, and since he was a Knight of the Order of St. John of Jerusalem, he likely spent a lot of time in the Mediterranean and perhaps died there.
You are not the father
The researchers also looked for living relatives who might share Richard's Y chromosome, which, like mitochondrial DNA, is passed down to children virtually unchanged. But the Y-chromosome is only passed down from father to son. And comparing this evidence against historical records can be problematic, because, as anyone who has watched "Maury" knows, the presumed father isn't always the actual father of the child. The same goes for royals.
The study authors found five men who, according to their family tree, should be male-line relatives of Richard III. All of these men share a common ancestor, Henry Somerset, fifth Duke of Beaufort, who died in 1803.
These men did not have the same Y chromosome as Richard. The researchers found one "break" in the male line between the five donors and Henry Somerset, meaning one of the donors was not genetically descended from Henry. But there was also at least one break somewhere in the 19 links between Richard III and Henry.
That's not to say Richard's Y chromosome is useless. It could eventually be used to acquit Richard of the murder of his two nephews. The young sons of Richard's brother Edward IV were not seen in public after Richard took the throne, leading to speculation that he had them murdered. (That accusation is repeated in William Shakespeare's play "Richard III," which paints the king as a villain.) Bones found during work on the Tower of London in the 17th century were accepted as the remains of the two boys and were buried in Westminster Abbey. A DNA test could prove whether those remains are authentic.
"We don't know for sure whether or not those remains are those of the princes," Schürer said. "We now have the Y chromosome of Richard III, and that should be identical to both of the princes since they shared the same paternal line."
But the fate of the two princes might remain a mystery. As The Guardian reported last year, the Church of England is unlikely allow any forensic testing on the remains out of fear of a flurry of royal exhumations.
There is also grave in Kent purported to hold the remains of an illegitimate child of Richard III, named Richard Plantagenet of Eastwell. He should have the same Y-chromosome as his father, and a DNA test might reveal whether or not that's the case, Schürer said.
Read more at Discovery News
The find has shed light on the origins of a plant that traps its food using leaves that act like fly paper.
The rare fossils, described in this week's Proceedings of the National Academy of Sciences, date back to between 35 and 47 million years ago, during the Eocene.
"This is the first discovery of a carnivorous plant fossil of this type," says one of the study's authors, Professor Alexander Schmidt, of the University of Gottingen in Germany.
The researchers suggest the fossil may be an early member of the Roridulacea family of carnivorous plants, which includes Roridula.
They found the fossil leaves are strewn with multicellular stalked glands or tentacles and unicellular hairs closely resembling those found on the leaves of Roridula, which is endemic to the Cape flora of South Africa.
Roridula traps insects on sticky leaves that act like fly paper and relies on resident symbiotic insects to digest its hapless prey.
"Carnivorous plants are found in many modern plant families, each with their own way of catching prey," says Schmidt.
"This specific trap is unique to the plant in South Africa."
Schmidt says the leaves were well preserved and very distinct from other flowering plant leaves, and were able to be compared with modern plant families still around today.
The researchers say the discovery shows the distribution of the Roridulacea family of carnivorous plants was far more wide spread during the Eocene than previously thought, challenging earlier notions about a Gondwanan origin of this family.
"We didn't expect to find these leaves in the European fossil record, because Roridula is restricted to South Africa," says Schmidt.
"However the amber insect fossil record does include many examples of Eocene insects that are today only found in areas like South Africa and Australia."
This means that while Europe wasn't geographically very far from its current location during the Eocene, Schmidt believes the climate of the day must have been slightly warmer.
Schmidt says most carnivorous plants on Earth today have no fossil record, the exception being seeds from the sundew Aldrovanda.
"Because they're not large, or made of wood, and because they decay quickly, carnivorous plants don't survive easily in the rock record, and so amber provides a chance to preserve something that is so rare," he says.
Schmidt and colleagues discovered two tiny leaves from the ancient carnivorous plant encased in Baltic amber which had been collected by a Hamburg couple who regularly collect and trade in amber.
"Baltic amber is the world's largest amber deposit, containing many fossils of insects and other arthropods, as well as some plant fossils," says Schmidt.
The amber was originally extracted from a mine near Kaliningrad in Russia.
Read more at Discovery News
The ability to break down alcohol likely helped human ancestors make the most out of rotting, fermented fruit that fell onto the forest floor, the researchers said. Therefore, knowing when this ability developed could help researchers figure out when these human ancestors began moving to life on the ground, as opposed to mostly in trees, as earlier human ancestors had lived.
"A lot of aspects about the modern human condition -- everything from back pain to ingesting too much salt, sugar and fat — goes back to our evolutionary history," said lead study author Matthew Carrigan, a paleogeneticist at Santa Fe College in Gainesville, Florida. "We wanted to understand more about the modern human condition with regards to ethanol," he said, referring to the kind of alcohol found in rotting fruit and that's also used in liquor and fuel.
To learn more about how human ancestors evolved the ability to break down alcohol, scientists focused on the genes that code for a group of digestive enzymes called the ADH4 family. ADH4 enzymes are found in the stomach, throat and tongue of primates, and are the first alcohol-metabolizing enzymes to encounter ethanol after it is imbibed.
The researchers investigated the ADH4 genes from 28 different mammals, including 17 primates. They collected the sequences of these genes from either genetic databanks or well-preserved tissue samples.
The scientists looked at the family trees of these 28 species, to investigate how closely related they were and find out when their ancestors diverged. In total, they explored nearly 70 million years of primate evolution. The scientists then used this knowledge to investigate how the ADH4 genes evolved over time and what the ADH4 genes of their ancestors might have been like.
Then, Carrigan and his colleagues took the genes for ADH4 from these 28 species, as well as the ancestral genes they modeled, and plugged them into bacteria, which read the genes and manufactured the ADH4 enzymes. Next, they tested how well those enzymes broke down ethanol and other alcohols.
This method of using bacteria to read ancestral genes is "a new way to observe changes that happened a long time ago that didn't fossilize into bones," Carrigan said.
The results suggested there was a single genetic mutation 10 million years ago that endowed human ancestors with an enhanced ability to break down ethanol. "I remember seeing this huge difference in effects with this mutation and being really surprised," Carrigan said.
The scientists noted that the timing of this mutation coincided with a shift to a terrestrial lifestyle. The ability to consume ethanol may have helped human ancestors dine on rotting, fermenting fruit that fell on the forest floor when other food was scarce.
"I suspect ethanol was a second-choice item," Carrigan said. "If the ancestors of humans, chimps and gorillas had a choice between rotten and normal fruit, they would go for the normal fruit. Just because they were adapted to be able to ingest it doesn't mean ethanol was their first choice, nor that they were perfectly adapted to metabolize it. They might have benefited from small quantities, but not to excessive consumption."
In people today, drinking in moderation can have benefits, but drinking in excess can definitely cause health problems, experts agree. Scientists have suggested that problems people have with drinking, such as heart disease, liver disease, and mental health problems, result because humans have not evolved genes to sufficiently process ethanol. Similarly, humans have not evolved genes to handle large amounts of sugar, fat and salt, which, in turn, have given way to obesity, diabetes, high blood pressure and many other health problems.
One model for the evolution of alcohol consumption suggests that ethanol only entered the human diet after people began to store extra food, potentially after the advent of agriculture, and that humans subsequently developed ways to intentionally direct the fermentation of food about 9,000 years ago. Therefore, the theory goes, alcoholism as a disease resulted because the human genome has not had enough time to fully adapt to alcohol.
Another model suggests that human ancestors began consuming alcohol as early as 80 million years ago, when early primates occasionally ate rotting fermented fruit rich in ethanol. This model suggests that the attraction to alcohol started becoming a problem once modern humans began intentionally fermenting food because it generated far more ethanol than was normally found in nature. The new findings support this model.
Read more at Discovery News
According to a story on Fox News, “Jucelino Nobrega da Luz, who says he predicted the deaths of Princess Diana and Brazilian racing legend Ayrton Senna, told authorities flight JJ3720, set to depart Wednesday from Sao Paulo to Brasilia, would develop engine trouble and crash on Sao Paulo’s main Paulista drag. Leaving nothing to chance, TAM changed the flight code to JJ4732 after receiving what it termed ‘indispensable information.’”
The renumbered flight took off and landed without a problem, though of course there’s no reason to think that anything different would have happened if they’d kept the original flight number. It’s not clear why Nobrega da Luz decided that the plane was in danger — nor why simply changing the flight number would prevent the disaster, according to him or the airlines. After all, it’s the same airplane, with the same pilot, crew and passengers. A rose by any other name would smell as sweet, though a flight by another name, apparently, is a whole different flight.
This is not the first time that a psychic has raised an alarm about a plane. In March 2004 a psychic claimed that a bomb was aboard an American Airlines flight at Southwest Florida International Airport. The bomb report resulted in a preboarding search by the TSA and Port Authority police. Despite a thorough examination with both equipment and bomb-sniffing dogs, nothing suspicious was found.
It’s easy to chide TAM airlines for what at first glance appears to be superstitious skittishness, but the situation is more complex than that. In public relations appearance is often more important than fact or truth.
Airlines don’t want to appear superstitious, but may have many customers who are. People often greatly exaggerate real risks to themselves, for example driving instead of flying because of safety fears (despite the fact that auto travel is far more dangerous than air travel). They underestimate their risk of contracting or dying from ebola while treating the deadly flu virus as an insignificant threat. If airline passengers don’t feel safe flying TAM for whatever reason — whether valid or imagined — then they will fly another airline or travel another way.
Companies know this, and they're often forced to officially respond in some way to address their client’s concerns. An airline can ignore and dismiss the claim, saying that they cannot allow anyone’s bad feeling or intuition to disrupt their operations. On the other hand, if the person making the claim is influential enough it may be easier and cheaper to simply change a flight number to appease the concerns of a vocal or superstitious minority.
Bad luck superstitions about travel have been common for millennia. For centuries fishermen and travelers about to embark on long and potentially uncertain ocean voyages, for example, performed rituals or entered the boat in a certain way -- often the starboard side -- to ward off bad luck and evil portents.
Iona Opie and Moira Tatem’s “A Dictionary of Superstitions” notes that the actions TAM airlines took in addressing the psychic’s concerns would have actually been thought to bring about disaster centuries ago because of the name change. Airplanes aren’t individually named but they do have flight numbers, which were changed in this case.
Read more at Discovery News
Dec 1, 2014
Knowing properties of materials at different temperatures is important in engineering, said Gregory McKenna, a professor of chemical engineering and the John R. Bradford Endowed Chair in Engineering. For example, the rubber O-ring that failed during the 1986 space shuttle disaster serves at a tragic case study of what can go wrong when decision-makers don't take this into account.
The problem, he said, is known properties of a material can radically change at the nanoscale -- a tiny scale about 1/1000 of the diameter of a human hair at which scientists have begun building machines that do work. McKenna and graduate student Meiyu Zhai looked at several polymers and explosive materials to see how surface properties varied at the nanoscale and how the surface impacts the nanoscale properties.
Their first results on the "multi-curve method" appeared in the peer-reviewed journal, Journal of Polymer Science Part B: Polymer Physics and was highlighted in Advances in Engineering.
"The nanoscale is a funny range of sizes where materials have properties that are not what we expect, even at a step up at the microscale," he said. "We are developing methods to characterize surface properties and relate them to nanoscale behavior using a nanoindenter and other nano-mechanical measurement methods."
In nanoindentation, researchers can investigate both the elastic properties (how materials spring back when pushed) or the viscous properties (how the material flows). The group has found several surprising results: For example, in other work, the team found extremely thin polycarbonate films become liquid-like at the nanoscale, while they are glassy at the macroscopic size scale. Nanoindentation can be used to relate surface properties to this observation.
As machines get smaller and smaller, McKenna said, knowing this information can be invaluable to future engineers.
The nanoindentation project was funded by The Office of Naval Research. The researchers also are funded by the National Science Foundation and the American Chemical Society-Petroleum Research Fund.
From Science Daily
Ideally, diamonds consist of pure carbon. But natural diamonds always contain defects. The most researched defects are nitrogen-vacancy centers comprising a nitrogen atom and a vacancy. These might serve as highly sensitive sensors or as register components for quantum computers. However, until now it has not been possible to extract the optically stored information electronically.
A team headed by Professor Alexander Holleitner, physicist at the TU München and Frank Koppens, physics professor at the Institut de Ciencies Fotoniques near Barcelona, have now devised just such a methodology for reading the stored information. The technique builds on a direct transfer of energy from nitrogen-vacancy centers in nanodiamonds to a directly neighboring graphene layer.
Non-radiative energy transfer
When laser light shines on a nanodiamond, a light photon raises an electron from its ground state to an excited state in the nitrogen-vacancy center. "The system of the excited electron and the vacated ground state can be viewed as a dipole," says Professor Alexander Holleitner. "This dipole, in turn, induces another dipole comprising an electron and a vacancy in the neighboring graphene layer."
In contrast to the approximately 100 nanometer large diamonds, in which individual nitrogen-vacancy centers are insulated from each other, the graphene layer is electrically conducting. Two gold electrodes detect the induced charge, making it electronically measureable.
Picosecond electronic detection
Essential for this experimental setup is that the measurement is made extremely quickly, because the generated electron-vacancy pairs disappear after only a few billionths of a second. However, the technology developed in Holleitners laboratory allows measurements in the picosecond domain (trillionths of a second). The scientists can thus observe these processes very closely.
"In principle our technology should also work with dye molecules," says doctoral candidate Andreas Brenneis, who carried out the measurements in collaboration with Louis Gaudreau. "A diamond has some 500 point defects, but the methodology is so sensitive that we should be able to even measure individual dye molecules."
Read more at Science Daily
In the summer of 2004, study author Jaelyn Eberle, a paleontologist and associate professor of geological sciences at the University of Colorado at Boulder, ventured out with her research team to Banks Island, which is Canada's westernmost Arctic island. The researchers were hoping to find fossils of mammals, but after spending about a week there, they had not found any. Moreover, the weather was cold and the researchers' tents were covered with snow, Eberle said.
This really is the pits, Eberle remembers thinking at the time.
But then the team started finding the teeth of ancient sharks.
"Probably the biggest surprise, at least at first, was that most of them — literally thousands of these things — belong to just two shark genera, and they are both within the sand type of sharks," Eberle said. The two genera are Striatolamia and Carcharias, according to the paper.
The researchers went back to the island in 2010 and 2012 to collect more shark teeth. They estimate that the teeth date to the late-early or middle Eocene epoch, or about 53 to 38 million years ago, according to the study, published in the November issue of the Journal of Vertebrate Paleontology.
The modern relatives of the two genera identified by the researchers live in warm, tropical waters, Eberle told Live Science.
Two of the teeth the researchers found belonged to an extinct species of sand shark, Odontaspis winkleri. And about 1 percent of the teeth belonged to species within the genus Physogaleus, related to sharpnose and tiger sharks, according to the study.
The researchers wondered why the diversity of the shark teeth they found was so low. "We have got four genera so it is not a lot of diversity, and yet we know during this time, the early Eocene, the climate was warmer than at any other time since the extinction of dinosaurs, and we know the Arctic was much warmer in the early Eocene [than it is now]," Eberle said. The warmer water would be expected to hold a higher diversity of shark species than what the researchers found.
The investigators estimated that the mean annual temperature in the Arctic at that time ranged from 8 to 14 degrees Celsius (46 to 57 degrees Fahrenheit) in the winter, and between 20 and 25 C (68 to 77 F) in the summer. This means that winter temperatures were above freezing.
There were alligators and giant tortoises living in the eastern Arctic at that time, Eberle said.
The researchers' analysis of the shark teeth revealed that the salinity of the coastal waters was very low at the time, Eberle said. In fact, the degree of salinity was closer to freshwater than that of a modern ocean, which many shark species could not tolerate, she said. This may explain the low shark diversity.
"You don't get a lot of sharks that can tackle that kind of low salinity," she said.
Read more at Discovery News
Still partially buried, the monolith measures 19.6 meters (64 feet) in length, 6 meters (19.6 feet) wide, and is at least 5.5 meters (18 feet) high. Its weight is estimated at a bulky 1,650 tons, making it biggest stone block from antiquity.
It was found by a team from the German Archaeological Institute in a stone quarry at Baalbek in Lebanon. Known as Heliopolis, “the city of the sun,” during the Roman rule, Baalbek housed one of the grandest sanctuaries in the empire.
The limestone quarry was located about a quarter of a mile from the temple complex and houses other two massive building blocks – one weighting about 1,240 tons, the other, known as the “Hajjar al-Hibla,” or The Stone of the Pregnant Woman, about 1000 tons.
Right next to the fully exposed Hajjar al-Hibla stone and underneath it, the archaeologists found a third block.
“The level of smoothness indicate the block was meant to be transported and used without being cut,” the German Archaeological Institute said in a statement.
“Thus this is the biggest boulder known from antiquity,” it added.
The team worked under the local supervision of Jeanine Abdul Massih, a long-term cooperation partner in the Baalbek project of the German Archaeological Institute’s Orient Department. The main purpose was to find new information about the mining techniques and the transportation of the megaliths.
Archaeologists believe the limestone blocks date back to at least 27 B.C., when Baalbek was a Roman colony and construction on three major and several minor temples began, lasting until the 2nd century A.D.
“Massive stone blocks of a 64-foot length were used for the podium of the huge Temple of Jupiter in the sanctuary,” the archaeologists said.
Only portions of the temple remain, including six massive columns and 27 gigantic limestone blocks at its base. Three of them, weighting about 1,000 tons each, are known as the “Trilithon.”
How these monoliths were transported and precisely positioned during the temple construction remains a mystery. Some even argue the block was laid by an unknown earlier culture predating even Alexander the Great, who founded Heliopolis in 334 B.C.
The newly uncovered stone block was likely cut to be used in the temple, but was probably abandoned because it was unsuitable for transporting.
Indeed, the Hajjar al-Hibla block nearby provided some clues: it was probably left in the quarry because the stone quality at one edge proved to be poor.
Read more at Discovery News
Nov 30, 2014
NOAA said the combined global land and ocean average surface temperature for the January-October period was 0.68°C (1.22°F) above the 20th century average of 14.1°C (57.4°F). For October, it was 0.74°C (1.33°F) above the 20th century average of 14.0°C (57.1°F).
The high October temperature was driven by warmth across the globe over both the land and ocean surfaces and was fairly evenly distributed between the Northern and Southern Hemispheres. The Southern Hemisphere had its hottest October on record and the Northern Hemisphere its third warmest.
October marked the third consecutive month and fifth of the past six with a record high global temperature for its respective month (July was fourth highest).
The Tokyo Climate Center, which is a WMO Regional Climate Centre, also reported that October was the hottest on record. The record was also confirmed by data from NASA's Goddard Institute for Space Studies.
WMO uses a combination of datasets to compile its annual Statement on the Status of the Global Climate. Additional information is drawn from the ERA-Interim reanalysis-based data set maintained by the European Centre for Medium-Range Weather Forecasts.
From Science Daily
The extent of sea ice cover in Arctic was much less than it is today between four and five million years ago. The maximum winter extent did not reaching its current location until around 2.6 million years ago. This new knowledge can now be used to improve future climate models.
"We have not seen an ice free period in the Arctic Ocean for 2,6 million years. However, we may see it in our lifetime. The new IPCC report shows that the expanse of the Arctic ice cover has been quickly shrinking since the 70-ies, with 2012 being the year of the sea ice minimum," Jochen Knies.
He is marine geologist at the Geological Survey of Norway (NGU) and Centre for Arctic Gas Hydrate, Climate and Environment, UiT The Arctic Univeristy of Norway.
In an international collaborative project, Jochen Knies has studied the trend in the sea ice extent in the Arctic Ocean from 5.3 to 2.6 million years ago. That was the last time Earth experienced a long period with a climate that, on average, was warm before cold ice ages began to alternate with mild interglacials.
Fossils reveal past sea ice extent
"When we studied molecules from certain plant fossils preserved in sediments at the bottom of the ocean, we found that large expanses of the Arctic Ocean were free of sea ice until four million years ago," Knies tells us.
"Later, the sea ice gradually expanded from the very high Arctic before reaching, for the first time, what we now see as the boundary of the winter ice around 2.6 million years ago ," says Jochen Knies, who is also attached to CAGE, the Centre for Arctic Gas Hydrate, Environment and Climate at the University of Tromsø, the Arctic University of Norway.
Arctic Ocean likely to be completely free of sea ice
The research is of great interest on the international stage because present-day global warming is strongly tied to a shrinking ice cover in the Arctic Ocean. By the end of the present century, the Arctic Ocean seems likely to be completely free of sea ice, especially in summer.
This may have major significance for the entire planet 's climate system. Polar oceans , their temperature and salinity, are important drivers for world ocean circulation that distributes heat in the oceans. It also affects the heat distribution in the atmosphere. Trying to anticipate future changes in this finely tuned system, is a priority for climate researchers. For that they use climate modeling , which relies on good data.
"Our results can be used as a tool in climate modelling to show us what kind of climate we can expect at the turn of the next century. There is no doubt that this will be one of many tools the UN Climate Panel will make use of, too. The extent of the ice in the Arctic has always been very uncertain but, through this work, we show how the sea ice in the Arctic Ocean developed before all the land-based ice masses in the Northern Hemisphere were established," Jochen Knies explains.
Seabed samples from Spitsbergen
A deep well into the ocean floor northwest of Spitsbergen was the basis for this research. It was drilled as part of the International Ocean Drilling Programme, (IODP), to determine the age of the ocean-floor sediments in the area. Then, by analysing the sediments for chemical fossils made by certain microscopic plants that live in sea ice and the surrounding oceans, Knies and his co-workers were able to fingerprint the environmental conditions as they changed through time.
"One thing these layers of sediment enable us to do is to "read" when the sea ice reached that precise point," Jochen Knies tells us.
The scientists believe that the growth of sea ice until 2.6 million years ago was partly due to the considerable exhumation of the land masses in the circum-Arctic that occurred during this period. "Significant changes in altitudes above sea level in several parts of the Arctic, including Svalbard and Greenland, with build-up of ice on land, stimulated the distribution of the sea ice," Jochen Knies says.
Read more at Science Daily