Mar 5, 2016
Crystals of kryptonite, a material deadly to Superman and his race, were supposed to have been created within the planet Krypton, and therefore most likely under very high pressure. The progenitor of the name, real krypton, is an element with an atomic number of 36, a noble gas considered to be incapable of forming stable chemical compounds. However, a publication in the journal Scientific Reports by a two-man team of theoretical chemists from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw, Poland, presents the possibility of synthesizing a new crystalline material in which atoms of krypton would be chemically bonded to another element.
"The substance we are predicting is a compound of krypton with not nitrogen, but oxygen. In the convention of the comic book it should, therefore, be called not so much kryptonite as kryptoxide. So if Superman's reading this, he can stay calm -- at the moment there's no cause for panic!" laughs Dr. Patrick Zaleski-Ejgierd (IPC PAS) and adds: "Our krypton monoxide, KrO, probably does not exist in nature. According to current knowledge, deep in the interiors of planets, that is, the only place where there is sufficient pressure for its synthesis, oxygen does not exist, nor even more so, does krypton."
Compounds of krypton have been produced before, in the laboratory under cryogenic conditions. They were, however, only single, linear and small molecules of the hydrogen-carbon-krypton-carbon-hydrogen type. The Polish chemists wondered if there were conditions in which krypton would not only bond chemically with another element, but also in which it would be capable of forming an extensive and stable crystal lattice. Their search, funded by an OPUS grant from the Polish National Science Centre, involved the researchers using genetic algorithms and models built on the so-called density functional theory. In the field of solid state physics, this theory has for years been a basic tool for the description and study of the world of chemical molecules.
"Our computer simulations suggest that crystals of krypton monoxide will be formed at a pressure in the range of 300 to 500 million atmospheres. This is a huge pressure, but it can be achieved even in today's laboratories, by skillfully squeezing samples in diamond anvils," says PhD student Pawe? Lata (IPC PAS).
Crystal lattices are built from atoms or molecules arranged in space in an orderly manner. The smallest repetitive fragment of such structures -- the basic 'building block' -- is called a unit cell. In crystals of table salt the unit cell has the shape of a cube, the sodium and chlorine atoms, arranged alternately, are mounted on each corner, close enough to each other that they are bound by covalent (chemical) bonds.
The unit cell of krypton monoxide is cuboid with a diamond base, with krypton atoms at the corners. In addition, in the middle of the two opposite side walls, there is one atom of krypton.
"Where is the oxygen? On the side walls of the unit cell, where there are five atoms of krypton, they are arranged like the dots on a dice showing the number five. Single atoms of oxygen are located between the krypton atoms, but only along the diagonal -- and only along one! Thus, on each wall with five krypton atoms there are only two atoms of oxygen. Not only that, the oxygen is not exactly on the diagonal: one of the atoms is slightly offset from it in one direction and the other atom in the other direction," describes Lata.
In such an idiosyncratic unit cell, each atom of oxygen is chemically bound to the two nearest adjacent atoms of krypton. Zigzag chains of Kr/O\Kr\O/Kr will therefore pass through the crystal of krypton monoxide, forming long polymer structures. Calculations indicate that crystals of this type of krypton monoxide should have the characteristics of a semiconductor. One can assume that they will be dark, and their transparency will not be great.
Theorists from the IPC PAS have also found a second, slightly less stable compound of krypton: the tetroxide KrO4. This material, which probably has properties typical of a metal, has a simpler crystalline structure and could be formed at a pressure exceeding 340 million atmospheres.
After formation, the two kinds of krypton oxide crystals could probably exist at a somewhat lower pressure than that required for their formation. The pressure on earth, however, is so low that on our planet these crystals would undergo degradation immediately.
Read more at Science Daily
“I’m kind of surprised how I do feel different physically than the last time, with regards to muscle soreness and joint pain,” Scott Kelly, 52, said during his first press conference since returning to Earth after 340 days in orbit.
Then, there’s what Kelly called “the skin issue.”
“Because I hadn’t touched anything for so long, (had) any significant contact, it’s very, very sensitive, almost like a burning feeling wherever I sit or lie or walk,” Kelly said.
Kelly and two Russian cosmonauts, including Mikhail Korneinko who was Kelly's crewmate through the year in space, landed in Kazakhstan late Tuesday.
Kelly, a veteran of three previous spaceflights, flew back to the Johnson Space Center in Houston the next day and immediately began a series of post-landing medical tests that will last about a year.
“Initially this time coming out of the capsule, I felt better than I did last time, but at some point those two lines have crossed and my level of muscle soreness and fatigue is a lot higher than it was last time,” Kelly said. “That was kind of unexpected.”
NASA and its space station partners flew Kelly and Kornienko for a year as a pilot program intended to pave the way for missions to Mars lasting more than two years. Typically, crews serve aboard the space station for six months.
Kelly told reporters the year passed slowly in space, but he could have stayed longer if it was for “a good reason,” such as a mission to Mars.
“It seemed like I lived there forever,” Kelly said.
The daily, 250-mile-high views of the planet left Kelly with a deeper appreciation of the environment.
“You can see a lot of pollution over parts of Asia that is almost continuous, constantly there. You can’t really see the ground very well. And those fires in California over the summer, that smoke was pretty extensive, covering large parts of the U.S.” Kelly said.
Read more at Discovery News
Mar 4, 2016
The fossil, dated to 100 million years ago, is an incredible 78 million years older than the previous oldest chameleon on record, according to a study, published in the journal Science Advances.
In addition to significantly pushing back chameleon origins, the fossil reveals that the infant lizard somehow became stuck in the resin of a coniferous tree during the Dinosaur Age. The predicament led to the eventual death and preservation of the chameleon.
The amber collection, housed at the American Museum of Natural History, also contained a fossilized gecko and another archaic lizard, both of which will be described in a future study. At least 10 other lizards were found in the amber, but they were not as well preserved.
“It was mind-blowing,” co-author Edward Stanley said of when he saw the fossils for the first time. “Usually we have a foot or other small part preserved in amber, but these are whole specimens — claws, toepads, teeth, even perfectly intact colored scales. I was familiar with CT technology, so I realized this was an opportunity to look more closely and put the lizards into evolutionary perspective.”
Stanley is a University of Florida postdoctoral student of herpetology at the Florida Museum of Natural History. Using a micro-CT scanner, he and his team looked inside the amber pieces without damaging the fossils. The scientists then digitally pieced together the tiny bones and soft tissues that they spotted.
“These fossils tell us a lot about the extraordinary, but previously unknown diversity of lizards in ancient tropical forests,” Stanley said in a press release. “The fossil record is sparse because the delicate skin and fragile bones of small lizards do not usually preserve, especially in the tropics, which makes the new amber fossils an incredibly rare and unique window into a critical period of diversification.”
The fossil of the chameleon challenges the view that these animals first evolved in Africa. It also suggests the evolutionary order of some of the lizard’s most distinctive features.
Read more at Discovery News
Biologists at Postojna Cave, a 15-mile-long (24 kilometers) cave system in southwestern Slovenia, are waiting with bated breath for the arrival of up to 55 baby olms (Proteus anguinus). These underground animals are also known as European cavesalamanders, but locals call them “human fish,” said Stanley Sessions, a biologist at Hartwick College in New York and a Fulbright scholar at the University of Ljubljana, Slovenia. That’s because their cave-adapted skin lacks pigment and is a fleshy pinkish-white color.
Olms are the largest of all cave-adapted animals, but they have long been enigmatic, Sessions and his colleague, Lilijana Bizjak Mali, of the University of Slovenia, wrote in an email to Live Science. They can grow up to 16 inches (40 centimeters) long. In the 1600s, people saw the long, slim bodies of these salamanders washed out of their cave habitats by rain and mistook them for baby dragons — an understandable impression, given the olms’ frilly gills, which look a bit like the neck frill of a fantastical dragon. The salamanders are blind, but very sensitive to smell, taste, sound and even electric fields, studies have found.
Postojna Cave is a major tourist attraction, complete with an aquarium where visitors can see olms in captivity. On Jan. 30, a tour guide noticed a single olm egg attached to the glass. This marked the beginning of the 20-day period in which olms can lay up to 60 eggs. Since then, biologists have counted 55 eggs, mostly clinging to the bottom of a rock and guarded zealously by the olm mother.
The appearance of the eggs is occasion for excitement among biologists because rearing olms in captivity is difficult, Sessions and Mali wrote. What’s more, olms live life in the slow lane: They don’t reach sexual maturity until age 14, and they can live to be at least 70 years old. Their metabolisim is so slow that olms can go without food for up to 10 years. They also have an unusually large genome, Sessions and Mali said, with about 15 times as many base pairs of nucleotides as humans.
Olm embryos usually take about 4 months to reach the hatching stage, the researchers said, so the aquarium can expect spring babies. An infrared camera allows tourists to see the eggs without approaching the olm tank. It’s not clear how many of the 55 eggs will actually hatch, but the offspring will look and function like mini-adults, Sessions and Mali said.
“As far as we know, the newly hatched Proteus larvae simply disperse soon after hatching, which is a good thing since the mother or other Proteus could eat them,” the researchers wrote.
Oddly, the embryonic olms will develop functional eyes, but their eyes degenerate after the early larval stage. By adulthood, the eyes are “nearly useless dots,” Sessions and Mali said.
Read more at Discovery News
Connecting to a large piece discovered in 1562, the new fragment bears an inscription that completes the word “Circus Flaminius.”
The map, known as Forma Urbis Romae, was carved into marble slabs between 203 and 211 A.D., during the rule of the emperor Septimius Severus.
Only fragments remain today and most are held in the Capitoline museum. They cover just 10 percent the original map surface that once stood on a wall in the Templum Pacis (Temple of Peace).
The wall still survives today in a building near the 6th-century Church of Santi Cosma e Damiano. Rows of holes where the map was attached using bronze clamps can still be seen.
Carved on 150 marble slabs, the 60-foot by 43-foot map detailed every building, street and staircase in Rome until it was partially ripped from the wall, probably to make lime for cement. What was left fell down and broke apart in hundreds of unrecognizable pieces.
Piecing the jigsaw puzzle together remains one of the great unsolved problems of archaeology. The first fragments were discovered in 1562. Since then, some 1200 pieces have been brought to light.
“Of these about 200 marble chips have been identified and ideally located on the modern topography,” the Superintendency said in a statement.
The new fragment was discovered in 2014 during work at the Palazzo Maffei Marescotti, a building owned by the Vatican.
The marble piece ended up there as it was likely recycled during the construction of the palace at the end of the 16th century.
The new fragment has allowed the researchers to piece together at least other three chunks of the huge puzzle, allowing a more comprehensive reading of an important area of ancient Rome.
Read more at Discovery News
FRBs release the same amount of energy in a single millisecond as the sun produces over 10,000 years. But what causes them and even where they come from has remained a mystery.
Evan Keane, a project scientist at the Square Kilometer Array Organization, and colleagues authored the original paper that claims to narrow down the source location of an FRB by tracing what they interpreted as the afterglow of whatever caused the FRB. But another group, led by Peter Williams, a postdoctoral astronomer at the Harvard-Smithsonian Center for Astrophysics, claims it could just be the belches of a monster black hole.
"We astronomers can currently only get relatively poor localizations for FRBs. For the search performed by the Keane team, they can narrow it down to an area about a quarter the size of the full moon," Williams told Space.com by email.
When Keane's team reviewed the region from which the FRBs originated, they found a faint glow within a galaxy along the line of sight. After watching it slowly fade over the course of six days, they concluded that the light had been produced by a sort of cataclysmic collision between powerful objects, such as a pair of merging black holes, which could have subsequently produced the original FRB.
But Williams and his team suggest that the glow is instead the result of the bright activity associated with a supermassive black hole at the heart of a galaxy, a feature known as an active galactic nuclei (AGN).
"The Keane team's paper does not consider the possibility that the origin galaxy is an AGN," Williams said. "Frankly, I'm not sure why this possibility was not investigated in the paper."
Every day, an estimated 10,000 FRBs explode across the sky. Despite their abundance, only a handful have been detected since their discovery in 2007. Most of these have been found using the Parkes radio telescope in Australia.
Pinpointing the sources of FRBs has remained a challenge over the decade and a half since they were first spotted. A number of causes have been suggested for FRBs. These include collisions between powerful objects such as dense neutron stars, which would demolish the sources. Other researchers have suggested less violent origins, such as changes in the magnetic field of highly magnetized neutron stars (the remains of collapsed stars) known as magnetars, which would allow the source to survive the FRB process.
Keane's team followed the trail of the FRB back to a galaxy with a dim afterglow suggestive of a powerful collision. According to Williams, however, following the trail is inconclusive.
"You can fit a lot of galaxies in that search area, so your odds of seeing an unrelated radio variable are not so bad," Williams said.
According to Williams' co-author Edo Berger, a professor of astronomy at Harvard University, the location uncertainty region for the FRB is about 200 times larger than the size of the signal. The FRB could come from anywhere within that region. The radio waves could have even passed through the galaxy, and their source could be hidden on the other side, forever out of sight.
"One reason that FRBs are exciting is that radio pulses can travel through all sorts of stuff," Williams said. "They would have no problem passing through a galaxy."
Most galaxies contain a supermassive black hole at their heart. In the Milky Way and others, the black hole is relatively quiet, sporadically consuming stars and dust. In others, material is constantly flowing into the black hole, and the resulting radiation produces a bright glow that can be seen across the universe. The strength of the signal can vary as the supply of material changes over time.
For Williams and his colleagues, the constant glow from the proposed source galaxy raised a red flag.
"I think that Keane et al glossed over the steady radio emission after the first six days," Berger said. "It was bright enough that only an AGN origin makes sense. This was what alerted us to a problem with their paper as soon as we read it."
Williams' team used the Very Large Array, run by the National Radio Astronomy Observatory, to observe the galaxy and found that the glow had not only remained steady but had brightened since the original observations, a finding Berger said supported the idea of an AGN source.
No current models suggest that an AGN could produce the fast radio bursts. Berger deemed them unlikely sources, because events that occur on such short timescales are difficult to produce near black holes. Williams also thinks it unlikely but not necessarily unreasonable.
"We know little enough about the physics of FRBs that I wouldn't want to say it's impossible," Williams said. "In fact, I wouldn't be shocked if an enterprising theorist gets inspired to cook up just such a model based on the past week's events."
Williams' team posted an informal paper online, which alerted other scientists of their conclusions.
"It looks like it comes from an AGN because of its spectrum and persistence," astronomer Avi Loeb, referring to the afterglow, told Space.com. Loeb serves as chairman of the Astronomy department and Direct of the Institute for Theory & Computation at Harvard University, and was not involved in either study.
Keane's team used the proposed source to "weigh" the material in the space it passed through. Their calculations matched models of the distribution of normal and dark matter through space. But according to Berger, those results could be a coincidence. The FRB could lie at approximately the same distance as the proposed source galaxy, which would give similar numbers even if it isn't in the same direction.
Loeb agreed that it was likely a coincidence.
"Given the error bars on the measurement, such a coincidence would not be unusual," he said.
Space.com reached out to the authors of the original research to ask for their thoughts on the idea of an AGN as the source of the glow.
"We are, of course, aware of work, and indeed are performing our own ongoing studies," Keane told Space.com.
Read more at Discovery News
Mar 3, 2016
A new study by researchers from England’s University of Exeter and Plymouth Marine Laboratory concludes that microplastics – those tiny pieces smaller than a millimeter in size, which are particularly hazardous to marine life -– are altering the sinking rates and other properties of zooplankton feces.
What happens is that the tiny marine creatures are consuming the plastic and excreting it. But the amount of polystyrene in the fecal pellets is making them lighter than normal, causing them to sink more slowly to the sea floor.
So why is that a big deal? Zooplankton feces, as it turns out, actually perform an important function in the marine environment, by transporting carbon and nutrients into deeper waters. That not only provides nourishment for animals who live in the ocean, but it also helps the oceans to store carbon, an important thing for controlling climate change.
Now, however, with the pellets sinking more slowly, there’s a greater opportunity for them to be ingested by marine animals. That transfers the plastic to their stomachs, where it can cause all sorts of harm.
“As these fecal pellets sink, they take the plastic with them.” the study’s leader, Exeter scientist Matthew Cole, explained in a press release. “This could be an important route by which floating plastic litter is removed from the sea surface down to the ocean depths.”
Zooplankton themselves are consuming plastic at an alarming rate, according to a 2015 study by Canadian scientists. That’s also worrisome in its own right, because as the bottom of the aquatic food chain, they’re eaten as food by many larger animals, and they pass along plastic in that fashion as well.
Read more at Discovery News
The galaxy, named GN-z11 and located in the direction of the constellation Ursa Major, formed just 400 million years after the Big Bang explosion that marks the beginning of the universe.
“We’ve taken a major step back in time, beyond what we’d ever expected to be able to do with Hubble,” Yale University astronomer Pascal Oesch said in a statement.
Oesch and colleagues used Hubble’s light-splitting spectrograph to image the unexpectedly bright galaxy, which is pumping out new stars at a rate that is about 20 times faster than what the Milky Way is producing today.
The scientists then analyzed how wavelengths of light from the galaxy had shifted due to the distance traveled. The phenomenon is similar to how the sound of train changes as it recedes into the distance.
Previously, the most distant galaxy was 13.2 billion years away.
“This new record will likely stand until the launch of the James Webb Space Telescope,” added Yale University astronomer Pieter van Dokkum.
The Webb observatory, a follow-on to the Hubble Space Telescope, is scheduled to fly in 2018. It is more sensitive to longer wavelength, infrared light that will allow researchers to look back at the first objects that radiated after the Big Bang explosion.
With just one percent of the mass of the Milky Way’s stars, GN-z11 is small by modern standards but huge considering how early it formed.
“It’s amazing that a galaxy so massive existed only 200 million to 300 million years after the very first stars started to form,” said astronomer Garth Illingworth with the University of California, Santa Cruz.
Read more at Discovery News
For example, a stellar embryo growing inside a gas cloud isn’t “fed” directly from that cloud; matter from the cloud spirals toward the baby star, creating a rapidly-swirling, hot disk. The star is therefore fed by the disk, which is itself fed by gas from the surrounding cloud. This disk acts almost like a mother’s placenta; it’s the placenta that provides nutrients for the developing embryo, not the mother herself.
But astronomers have not been able to precisely observe where the disk around a newborn star ends (the “placenta”) and where the inner boundary of the gas cloud (the “mother”) begins. Now, astronomers using the stunningly powerful Atacama Large Millimeter/submillimeter Array (ALMA) have seen this boundary, a direct observation that will undoubtedly improve star (and planetary) formation models.
“The disks around young stars are the places where planets will be formed,” said Yusuke Aso, of the University of Tokyo and lead author of a paper published in the Astrophysical Journal. “To understand the formation mechanism of a disk, we need to differentiate the disk from the outer envelope precisely and pinpoint the location of its boundary.”
Zooming in on a protostar named TMC-1A, which is located around 450 light-years away in the constellation Taurus, Aso’s team were able to see its spinning inner disk (the protoplanetary disk) and differentiate it from the cloud feeding it. ALMA’s extreme precision at measuring velocity distributions was key to this endeavor.
In the case of TMC-1A, the transition boundary from spinning disk to surrounding gas cloud envelope was measured to extend 90 AU (astronomical units; where 1 AU is the average distance the Earth orbits the sun) from the central baby star, a distance 3-times bigger than the orbit of Neptune. What’s more, the ALMA observations revealed the protostar’s disk obeys Keplarian motion; the material closest to the star orbits faster, whereas the material further out orbits slower.
This is important: using the rotation speed of the disk’s gas, the researchers could calculate the mass of the baby star. This stellar infant “weighs in” at a healthy 0.68 times (68 percent, or roughly two-thirds) the mass of our sun. They were also able to deduce the rate matter was falling from the disk onto the star — one-millionth of the mass of our sun is falling into TMC-1A every year at a speed of 1 kilometer per second.
Read more at Discovery News
Mars’ original north and south poles, in other words, are no longer where they once were.
The findings explain the unexpected location of dry river beds and underground reservoirs of water ice, as well as other Martian mysteries that have long perplexed scientists, the lead researcher told AFP.
“If a similar shift happened on Earth, Paris would be in the Polar Circle,” said Sylvain Bouley, a geomorphologist at Universite Paris-Sud.
“We’d see Northern Lights in France, and wine grapes would be grown in Sudan.”
The volcanic upheaval, which lasted a couple of hundred million years, tilted the surface of Mars 20 to 25 degrees, according to the study.
The lava flow created a plateau called the Tharsis dome more than 5,000 square kilometers (2,000 square miles) wide and 12 km (7.5 mi) thick on a planet half the diameter of Earth.
“The Tharsis dome is enormous, especially in relation to the size of Mars. It’s an aberration,” Bouley said.
This outcropping — upward of a billion billion tonnes in weight — was so huge it caused Mars’ top two layers, the crust and the mantle, to swivel around, like the skin and flesh of a peach shifting in relation to its pit.
Already in 2010, a theoretical study showed that if the Tharsis dome were removed from Mars, the planet would shift on its axis.
Bouley and colleagues matched these computer models with simulations and observations — their own and those of other scientists.
Many things on Mars that begged explanation suddenly make sense in light of the new paradigm.
“Scientists couldn’t figure out why the rivers” — dry riverbeds today — “were where they are. The positioning seemed arbitrary,” Bouley told AFP.
“But if you take into account the shift in the surface, they all line up on the same tropical band.”
Read more at Discovery News
Mar 2, 2016
Hailed as one of the most important archaeological finds in the UK in decades, the island was located in the village of Little Carlton, near Louth, Lincolnshire.
Once home to a Middle Saxon settlement, the site was first discovered by Graham Vickers, a local metal detector hobbyist. While searching a plowed field, Vickers found a silver stylus, which is an ornate writing tool dating from the eighth century.
That was just the first of many intriguing items that were to emerge from the field.
After alerting England’s Portable Antiquities Scheme, Vickers returned to the site and unearthed hundreds of other artifacts, recording their location with a GPS system.
The items include another 20 styli, about 300 dress pins, a huge number of “sceattas” – coins from the 7th-8th centuries – and a small lead tablet bearing the female Anglo-Saxon name, Cudberg.
Later, a team from the University of Sheffield found bones of a butchered animal and Saxon pottery.
“This is a site of international importance,” Hugh Willmott, from the university’s department of archaeology, said in a statement.
It is thought the settlement might have been an island monastery or a trading center, but archaeologists have just begun investigating it.
Using geophysical and magnetometry surveys along with 3D modelling, the researchers digitally restored the water level of the island to its higher medieval state.
“It is enclosed between a basin and a ditch,” Willmott told The Guardian.
Read more at Discovery News
The dragonfly’s estimated range is greater than 4,400 miles, which shatters the prior record set by the monarch butterfly, which flies about 2,500 miles each way during its migration across North America, the authors write.
The length of the dragonfly’s journeys even exceed the distance of Charles Lindbergh’s celebrated solo flight from New York to Paris by at least several hundred miles, according to the study, which is published in the journal PLOS ONE.
The research itself has set a record, becoming the first to use DNA to study how far this species of dragonfly — commonly known as the globe skimmer or wandering glider — can travel.
“This is the first time anyone has looked at genes to see how far these insects have traveled,” senior author Jessica Ware, an assistant professor of biology at Rutgers University-Newark, confirmed in a press release.
She added, “If North American Pantala only bred with North American Pantala, and Japanese Pantala only bred with Japanese Pantala, we would expect to see that in genetic results that differed from each other. Because we don’t see that, it suggests the mixing of genes across vast geographic expanses.”
Ware and her team determined that populations of the dragonfly from Texas, eastern Canada, Japan, Korea, India, and South America have nearly identical genetic profiles. This connection has only one likely explanation, according to the researchers: The dragonflies are traveling very long distances, breeding at their destination sites and are creating a common worldwide gene pool.
The dragonfly’s size makes the travel all the more surprising, as usually only relatively large animals are able to carry enough “fuel” to energize such lengthy trips. Godwits (birds) can carry fat within their bodies that helps them to fly over 7,000 miles non-stop, for example. Blubber-packed humpback whales have been documented as swimming over 6,000 miles.
For the dragonfly, their travels skills are more about their body’s sleek design and their flying technique.
“These dragonflies have adaptations such as increased surface areas on their wings that enable them to use the wind to carry them,” Ware explained. “They stroke, stroke, stroke and then glide for long periods, expending minimal amounts of energy as they do so.”
As for why they go to all the trouble to travel so much, co-author Daniel Troast said that the dragonfly is “following the weather.”
One example is that “they’re going from India where it’s dry season to Africa where it’s moist season, and apparently they do it once a year,” he said.
Read more at Discovery News
Dated to between 325 B.C. -- two years before Alexander the Great’s death -- and 300 B.C., the tomb is located in Amphipolis, east of Thessaloniki, and is billed as the largest of its kind in the Greek world, measuring more than 1,600 feet in circumference.
According to study author Andrew Chugg, a missing Π, or pi, clearly discards the archaeologists’s theory linking the burial to Hephaestion, Alexander the Great’s beloved friend and general.
Chugg argues that the blocks, originally cut for monuments to Hephaistion on Alexander’s order, were simply re-used to build the massive tomb a few years after the Macedonian king’s death.
Last October, head archaeologist Katerina Peristeri announced at a conference in Thessaloniki that three inscriptions pointed to the individual originally commemorated by the mysterious monument
“Chances are that this is a funerary heroon (hero worship shrine) dedicated to Hephaestion,” Peristeri said.
The announcement came at the end of an extraordinary exploration that for months wound through huge decapitated sphinxes, walls guarded by colossal female statues, and floors decorated with stunning mosaics.
At the end of the digging, bone fragments were found. They belonged to at least five individuals who were identified as being a woman, two men, a newborn baby and a cremated adult whose gender could not be verified.
Featuring the monogram of Hephaestion, the three inscriptions were decoded to read: ΠΑΡΕΛΑΒΟΝ ΗΦΑΙΣΤΙΩΝ ΑΝΤ. According to Peristeri and her team, they meant “I, Antigonus received construction material for the erection of a monument in honor of Hephaestion.”
During her presentation, Peristeri showed sketches and photos of two inscriptions which read ΑΡΕΛΑΒΟΝ. The word would have stood for ΠΑΡΕΛΑΒΟΝ, meaning “received by” or “received for.”
“They left a blank space in their drawing. Everyone thought it meant the Π was simply not there on the stone of the block,” said Chugg, who also authored "The Quest for the Tomb of Alexander the Great."
But a photo taken in the 1970s of one of the ΑΡΕΛΑΒΟΝ blocks might reveal a different scenario. The photo was taken when a number of loose blocks from the mound’s retaining wall were catalogued by the American School of Classical Studies in Athens.
Such blocks were rediscovered in the River Strymon just south of Amphipolis a hundred years ago and seem to have been re-used by the Romans to build a causeway or dam across the river.
The inscription in the 1970s photo, which Peristeri believed was a contract for the construction of the massive burial, was one of the loose blocks found in the River Strymon.
“The photo doesn’t match the sketches of the inscriptions made by Peristeri and shows that the part of the block where the Π should have been is actually missing,” Chugg said.
“Persteri’s drawings place the edges of the blocks much further from the letters than they are on the actual blocks,” he added.
Chugg believes the Π is missing from the word ΠΑΡΕΛΑΒΟΝ because the blocks were shortened after they had been inscribed in order to fit them into the walls of the tomb.
“This means the Amphipolis tomb is not the monument for which they were originally quarried and dressed, because they would then have been quarried at the correct size,” he added.
The claim comes just days before the annual conference on archaeological works in Macedonia and Thrace which is expected to reveal further details on the mysterious burial.
Chugg agrees with Peristeri that the stone blocks may have been cut for monuments to Hephaestion on Alexander’s orders.
Read more at Discovery News
The finds come from an analysis of dozens of ancient fossil remains collected across Europe.
The genetic turnover was likely the result of a rapidly changing climate, which the earlier inhabitants of Europe couldn’t adapt to quickly enough, said the study’s co-author, Cosimo Posth, an archaeogenetics doctoral candidate at the University of Tübingen in Germany.
The temperature change around that time was “enormous compared to the climactic changes that are happening in our century,” Posth told Live Science. “You have to imagine that also the environment changed pretty drastically.”
A twisted family tree
Europe has a long and tangled genetic legacy. Genetic studies have revealed that the first modern humans who poured out of Africa, somewhere between 40,000 and 70,000 years ago, soon got busy mating with local Neanderthals. At the beginning of the agricultural revolution, between 10,000 and 12,000 years ago, farmers from the Middle East swept across Europe, gradually replacing the native hunter-gatherers. Around 5,000 years ago, nomadic horsemen called the Yamnaya emerged from the steppes of Ukraine and intermingled with the native population. In addition, another lost group of ancient Europeans mysteriously vanished about 4,500 years ago, a 2013 study in the journal Nature Communications found.
But relatively little was known about human occupation of Europe between the first out-of-Africa event and the end of the last ice age, around 11,000 years ago. During some of that time, the vast Weichselian Ice Sheet covered much of northern Europe, while glaciers in the Pyrenees and the Alps blocked east-west passage across the continent.
To get a better picture of Europe’s genetic legacy during this cold snap, Posth and his colleagues analyzed mitochondrial DNA — genetic material passed on from mother to daughter — from the remains of 55 different human fossils between 35,000 and 7,000 years old, coming from across the continent, from Spain to Russia. Based on mutations, or changes in this mitochondrial DNA, geneticists have identified large genetic populations, or super-haplogroups, that share distant common ancestors.
“Basically all modern humans outside of Africa, from Europe to the tip of South America, they belong to these two super-haplogroups that are M or N,” Posth said. Nowadays, everyone of European descent has the N mitochondrial haplotype, while the M subtype is common throughout Asia and Australasia.
The team found that in ancient people, the M haplogroup predominated until about 14,500 years ago, when it mysteriously and suddenly vanished. The M haplotype carried by the ancient Europeans, which no longer exists in Europe today, shared a common ancestor with modern-day M-haplotype carriers around 50,000 years ago.
The genetic analysis also revealed that Europeans, Asians and Australasians may descend from a group of humans who emerged from Africa and rapidly dispersed throughout the continent no earlier than 55,000 years ago, the researchers reported Feb. 4 in the journal Current Biology.
Time of upheaval
The team suspects this upheaval may have been caused by wild climate swings.
At the peak of the ice age, around 19,000 to 22,000 years ago, people hunkered down in climactic “refugia,” or ice-free regions of Europe, such as modern-day Spain, the Balkans and southern Italy, Posth said. While holdouts survived in a few places farther north, their populations shrank dramatically.
Then around 14,500 years ago, the temperature spiked significantly, the tundra gave way to forest and many iconic beasts, such as woolly mammoths and saber-toothed tigers, disappeared from Eurasia, he said.
Read more at Discovery News
The SDO was launched in 2009 and placed in a near-circular, 22,238 mile geosynchronous orbit around Earth. For the vast majority of its observing time of our nearest star, the SDO has an unblocked, pristine view, returning the highest-definition observations of solar phenomena such as solar flares, coronal mass ejections (CMEs), coronal loops, prominences and sunspots. Occasionally, however, the Earth inevitably lines up just right during its solar orbit that it creeps into the SDO’s frame and interrupts the photo session.
We are currently in the middle of the 2016 spring eclipse season that will last until March 12. It began on Feb. 19. Every year there are 2 eclipse seasons, both near the equinoxes — a bi-annual event when the sun is positioned directly over the Earth’s equator and the Northern and Southern Hemispheres receive the same amount of sunlight.
As can be expected around the start and end of the SDO eclipse season, the amount of solar blockage is limited, but in the middle of the eclipse season (around now), the eclipse can last up to 72 minutes.
Any spacecraft orbiting the Earth that observes the sun contend with these eclipses, but the SDO is in an orbit designed to minimize the interruption.
This animation is constructed of ultraviolet observations made by the SDO at a wavelength of 304 Angstroms. At this wavelength, features in the sun’s lower corona (the sun’s multimillion degree atmosphere) can be resolved. The brightest patches are where highly energetic plasma heating processes are underway, producing so-called active regions.
As the Earth passes in front, these regions can be seen through the fuzzy edge of the Earth as the UV light penetrates through our atmosphere.
From Discovery News
Mar 1, 2016
PhD student Alessandro Chiarenza, then at the University of Bologna and now at Imperial College London, asked officials with the Museum of Geology and Palaeontology in Palermo, Italy if he could examine a fossilized femur that had previously gone unidentified.
After Chiarenza's analysis, it turned out that the bone was from a 95-million-year-old representative of abelisauridae, a group of dinosaurs that had powerfully muscled hind limbs, razor-sharp teeth, tiny forelimbs, and probably feathers.
The abelisaur Chiarenza studied would have been about 29 and a half feet (9 meters) long and likely weighed 1 to 2 tons, and those numbers have given scientists a better idea of the peak size of these dinos.
“Smaller abelisaur fossils have been previously found by palaeontologists, but this find shows how truly huge these flesh-eating predators had become,” said Chiarenza, in a statement. “Their appearance may have looked a bit odd, as they were probably covered in feathers, with tiny, useless forelimbs, but make no mistake: They were fearsome killers in their time.”
The big dino lived in late-Cretaceous North Africa, a tropical world of rivers and mangrove swamps, with plenty of large fish, turtles, crocodiles and other dinosaurs to eat.
The femur came from a fossil bed in Morocco called the Kem Kem Beds, known for containing dinosaur remains from five — now six, including abelisaur — different groupings of predators.
Scientists have long puzzled over how so many predators could have coexisted in the same place without tearing each other to bits.
Chiarenza and University of Bologna colleague Andrea Cau argue that abelisaur and friends actually lived apart from each other, in different environments, and that over time the changing geology of the region mixed the fossils of the different predators together.
“Rather than sharing the same environment, which the jumbled-up fossil records may be leading us to believe,” Chiarenza said, “we think these creatures probably lived far away from one another in different types of environments.”
Read more at Discovery News
The discovery, which will be reported in the April issue of the Journal of Archaeological Science, adds the rock shelter — called Wadi Sūra II — to the very short list of places containing animal stencils made with actual animals.
"Animal hand or foot stencils are not as common as human ones in the rock art record," wrote Emmanuelle Honoré and colleagues. "Emu foot stencils are evidenced in the Carnavon Gorge and the Tent Shelter in Australia, choike/nandu (birds of the genus Rhea) stencils in the rock art of La Cueva de las Manos in Argentina, bird stencils in Arnhem Land in Australia, among others."
“All these animal stencils are made with tridactyl (three-toed) feet,” continued Honoré of the McDonald Institute for Archaeological Research and her team. “As such, as far as we know, the Wadi Sūra II shelter would represent the first record ever identified of non-human pentadactyl (five toed or fingered) hand stencils in the world of rock art.”
The researchers launched their investigation after noticing that the hands were not as human resembling as previously thought. Yes, they have five digits, but from there, the similarities end. The hand stencils are very small, for example, such that even earlier teams concluded that human babies must have made them.
Honoré and colleagues took detailed measurements of each hand stencil on the walls of the rock shelter, located in the Egyptian part of the Libyan Desert. They did a comparative study, looking at human newborn hands and even those of pre-term babies. They still couldn’t make a match.
Next, they looked at the hands of other animals that also have five digits. These included a 4-year-old crocodile from the zoological garden at the University of Tel Aviv and adult monitor lizards from the wild as well as the Zoo of Moscow. The reptiles surprisingly proved to be a better match. You can see what one looks like here.
As for how the stencils were made, the researchers believe that they were crafted “by placing a hand or animal foot on the surface rock, and then blowing a pigment onto the substrate to create an outline or a negative image of the hand or foot.”
Given the scientists’ conclusion that the hands were reptilian and not human, many of the images in the rock shelter take on new complex meanings. For example, one wall features stencils of actual human hands with the tiny reptile hands on top of them, as though they are being held by the person.
Read more at Discovery News
The resulting accumulation of stones either next to or in the hollows of the trees has created a new puzzle for chimp researchers:
Chimp stone throwing compilation from laura kehoe on Vimeo.
Scientists from the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) made the discovery with the help of camera traps, placed after field teams noticed piles of stones next to trees at some of their dozens of research sites.
The behavior was exhibited primarily by adult male chimps, but the scientists said some females and juveniles were also seen throwing the stones.
Data on these observations have just been published in the journal Scientific Reports.
“This study reports a new chimpanzee behavior not known,” said Christophe Boesch, a study co-author from the MPI-EVA, in a press release. “As the stone accumulation behavior does not seem to be linked to either the abundance of stones or the availability of suitable trees in an area, it is likely that it has some cultural elements.”
Chimps are known to use tools when foraging for food, such as using sticks to poke around for termites or to extract honey or ants. They’ll also use stone or wooden “hammers” to smash nuts open.
But the researchers say the stone-throwing activity doesn’t seem to have anything to do with foraging.
“This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees,” the authors of the study wrote.
Read more at Discovery News
The fossil represents the oldest and most detailed central nervous system ever found, reports the study, which is published in the journal Proceedings of the National Academy of Sciences.
The vast majority of fossils only reveal bone and other hard body parts, such as teeth, since the nervous system and soft tissues are essentially made of fatty-like substances that degrade over time.
"This is a unique glimpse into what the ancestral nervous system looked like," study co-author Javier Ortega-Hernández of the University of Cambridge's Department of Zoology said of the fossil in a press release. "It's the most complete example of a central nervous system from the Cambrian period."
The animal, Chengjiangocaris kunmingensis, lived during a key part of Earth’s history known as the Cambrian explosion, a time during which rapid evolutionary development took place. At this time about a half billion years ago, most major animal groups first appear in the fossil record.
C. kunmingensis was a type of animal known as a fuxianhuiid, and was an early ancestor of modern insects, spiders and crustaceans.
Its nervous system featured a nerve cord running throughout its body. The nerve cord was similar to the spinal cord that we and many other organisms have today. Bead-like ganglia, or bundles of nerve cells, controlled the animal's single pair of walking legs.
Ortega-Hernández and his team closely examined the exceptionally preserved ganglia and discovered dozens of spindly fibers, each measuring about five thousandths of a millimeter in length.
“These delicate fibers displayed a highly regular distribution pattern, and so we wanted to figure out if they were made of the same material as the ganglia that form the nerve cord,” he explained. “Using fluorescence microscopy, we confirmed that the fibers were in fact individual nerves, fossilized as carbon films, offering an unprecedented level of detail. These fossils greatly improve our understanding of how the nervous system evolved.”
The researchers found that some aspects of the creature's nervous system are similar to that of modern velvet worms and penis worms, which really do resemble the male sexual organ. All of these animals have regularly spaced nerves that emanate from the central nerve cord.
Conversely, dozens of these nerves were independently lost over evolutionary time in many living animals including water bears, which are eight-legged segmented water-dwelling organisms that are so tiny that scientists refer to them as "micro-animals." The loss of the nerves over time in many species suggests that simplification played an important role in the evolution of the nervous system.
Read more at Discovery News
The naturally mummified body of German adventurer Manfred Fritz Bajorat, 59, was found by two fishermen who spotted a battered vessel in the Philippine Sea about 60 miles from Barabo.
“A white yacht floating with a destroyed sail prompted them to enter the boat to verify further,” the Barobo Police Station said in a Facebook post.
Certificates found on the vessel revealed Bajorat and his wife Claudia crossed the equator aboard another ship, the Hyundai Renaissance in 2008.
In that year, however, the couple split. Bajorat continued his round-the-world sail alone; Claudia died from cancer in 2010.
The mummy is estimated to be between one year and seven years old. It’s yet unknown how long the dead mariner had been sailing on his yacht: sightings of him have not been reported since 2009.
A yachtsman told the German magazine Bild that he met Bajorat in Mallorca in 2009.
“He was a very experienced sailor. I don’t believe he would have sailed into a storm. I believe the mast broke after Manfred was already dead,” he told Bild.
Forensic examiners said natural mummification occurred because dry ocean winds, hot temperatures and salty air helped preserve the body. Post-mortem examination found no evidence of foul play, so it is believed Bajorat had died of natural causes.
The final position in which the body was mummified suggests Bajorat possibly succumbed to a heart attack.
German officials are trying to trace any relatives in the hope they can help reconstruct the circumstances and time of death.
From Discovery News
Feb 29, 2016
What he found on the Tel Rehov mound completely stunned him and his friends. Just beneath the soil, they discovered a 3,400-year-old clay figurine with a portrait of a naked woman. It has since been compared by antiquity authorities to figurines from the Canaanite culture of the 15th to 13th centuries BCE.
“Ori returned home with the impressive figurine and the excitement was great,” Ori’s mother, Moriya Greenhut, said in a statement. “We explained to him this is an ancient artifact and that archaeological finds belong to the State.”
The Greenhut family turned palm-sized figurine over to the Israel Antiquities Authority. The clay figurine is believed to have been made by pressing soft clay into a mold.
“Some researchers think the figure depicted here is that of a real flesh and blood woman, and others view her as the fertility goddess Astarte, known from Canaanite sources and from the Bible,” Amihai Mazar, professor emeritus at Hebrew University and expedition director of the archaeological excavations at Tel Rehov who examined the figurine, said in a statement.
“It is highly likely that the term trafim mentioned in the Bible indeed refers to figurines of this kind,” Mazar said. “Evidently the figurine belonged to one of the residents of the city of Rehov, which was then ruled by the central government of the Egyptian pharaohs.”
From Discovery News
Back then, Julius Caesar took the advice of the learned astronomer Sosigenes of Alexandria, who knew from Egyptian experience that the tropical year (also known as the solar year) was about 365.25 days in length. So to account for that residual quarter of a day, an extra day — a leap day — was added to the calendar every four years.
This new “Julian” calendar was used throughout the Roman Empire and by various Christian churches. At that time, February was the last month of the year.
Initially, in order to make a proper transition from the Roman calendar (which had 355 days and which was basically a lunar calendar) to the Julian calendar, and to get the months and various feast days and holidays back into their normal seasons, 90 extra days were inserted into the year 46 B.C. Caesar divided these 90 extra days into three temporary months.
One month was added between February and March. Two other months (Intercalaris Prior and Intercalaris Posterior) were added after November. The end result was a year that was 15 months and 445 days long, and was nicknamed Annus Confusionus — the Year of Confusion.
Then, to honor his contribution to timekeeping, Julius Caesar later renamed the fifth month (formerly known as Quintilis) after himself (July). See what sweeping changes you can make when you’re an emperor?
The Julian calendar worked so well at first that many countries adopted it. Unfortunately, it was flawed, being 0.0078 of a day (about 11 minutes and 14 seconds) longer than the tropical year.
So, the Julian calendar introduced an error of one day every 128 years, which means that, every 128 years, the tropical year shifts one day backward with respect to the calendar. This made the method for calculating the dates for Easter inaccurate.
As a result, by the year 1582 — thanks to the overcompensation of observing too many leap years — the calendar had fallen out of step with the solar year by a total of 10 days. It was then that Pope Gregory XIII stepped in and, with the advice of a German Jesuit mathematician and astronomer named Christopher Clavius, produced our current Gregorian calendar.
First, to catch things up, 10 days were omitted after Thursday, Oct. 4, 1582, making the next day Friday, Oct. 15. This edict was most unpopular; many people felt that 10 days had been taken from their lives. There were riots in the streets throughout Europe, and workers demanded their 10 days’ pay — forgetting, conveniently, that they hadn’t worked those 10 days! Thankfully, the hubbub eventually died down.
Next, to more closely match the length of the tropical year, “century years” were declared not to be leap years (though they had been leap years in the old Julian calendar). The exceptions were those century years divisible by 400.
And that’s why the year 2000 was a leap year, but 1700, 1800 and 1900 were not.
Some couldn’t let go
The Gregorian calendar, however, was not adopted by the American Colonies until 1752. That’s why George Washington was not born on Washington’s Birthday.
In our time, we celebrate Washington’s Birthday on Feb. 22. But the United States’ first president was born in 1732 — and by that time, the error in the Julian calendar had increased to 11 days. So a calendar hanging on the wall where Washington was born would have read Feb. 11, 1732.
And if you think the 20 years that it took the American Colonies to finally ratify the Gregorian calendar was a long time, that was nothing compared to Russia, which finally accepted calendar reformation in 1918.
And Greece held out even longer — all the way to 1923!
The Gregorian calendar has proven to be far superior to the Julian calendar. Over a span of one year, it runs 26 seconds too fast, but that’s an error so slight that it will not be necessary to eliminate a day from the calendar until around the year 5300.
Still, some people would like to see our calendar changed yet again. One of the more popular proposals is the World Calendar created by Elisabeth Achelis of The World Calendar Association in 1930.
The World Calendar consists of 364 days. The year would be divided into four quarters, with each quarter consisting of three months. The first month of each new quarter (January, April, July and October) would have 31 days and would always begin on a Sunday. All the remaining months would have just 30 days.
In such a setup, each date would fall on the same day of the week every year. So if you were born on a Tuesday, your birthday would always fall on a Tuesday. Independence Day would always fall on a Wednesday; Christmas Day would be a Monday; and Thanksgiving would finally have a fixed date: Nov. 23, since the fourth Thursday in November on the World Calendar would always be on that date.
Triskaidekaphobes likely would not like this new setup; it would mean four Friday the 13ths every year. (Currently, the maximum number for any given year is three.)
But wait! This is a 364-day calendar. What happens to day 365? And what about leap years?
Dec. 31 would be recognized as “Worldsday” (a world holiday). It would come between Saturday, Dec. 30 and Sunday, Jan. 1. As for leap years, the extra day would be inserted not at the end of February as it is now, but at the end of June. June 31 would thus become a second World Holiday; like the Olympics, it would be celebrated every four years.
In the Jan. 17, 2016, issue of Parade magazine, Marilyn vos Savant answered a question from a reader who wanted to know if there were a “less clunky” alternative to our present calendar.
Read more at Discovery News
A recent PBS Frontline report showed how Zika strained the country’s health care system — the largest in the world — which was already overwhelmed by a huge increase in two other mosquito-borne illnesses: dengue fever and chikungunya. Pouring gasoline on the fire is an economic crisis resulting in fewer doctors and nurses to a combat greater numbers of cases.
And of course, it isn’t just Brazil. The spread of Zika across the Americas has prompted the World Health Organization to declare a public health emergency.
One of the questions raised about the outbreak is whether climate change is involved. After all, it has to varying degrees also been implicated in the spread of other mosquito-borne diseases. There have been big increases in cases of West Nile Virus and dengue in the United States, while chikungunya has recently been reported in western Europe.
And if climate change is responsible, it’s easy to understand why. As temperatures around the country rise, the areas that are conducive to such mosquitoes could expand, and the insects could start to emerge earlier in the year, meaning more opportunities for bites that could spread disease. It’s notable that the 2012 West Nile Virus outbreak in the United States followed an unseasonably warm late, spring, summer and early fall. But within that overall trend, there some nuance.
For example, temperatures more conducive to mosquitoes won’t necessarily mean conditions that are more conducive to the pathogens they transmit. There are a lot of Aedes aegeypti mosquitoes, an invasive species, in Arizona, but no dengue fever, which they often carry. It’s possible that because A. aegypti thrives in environments that are moist as well as warm, Arizona’s desert climate doesn’t allow the mosquito to live long enough for the dengue parasite to go through its full life cycle.
So, as climate change increases drought in some areas, should those places cross dengue fever off their lists of things to be worried about? Not so fast, because as with many diseases, human behavior also plays a role. Because A. aegypti often breed in containers used for household water storage, and because the need for such water storage containers will increase in areas projected to be more prone to drought as climate continues to change, there may ultimately be more opportunities for dengue-carrying mosquitoes in arid environments.
There are other factors, as well. Australia, for example, has seen increased cases of the Ross River Virus, which is the most common mosquito-borne disease in that country. And while climate may be part of the reason for this increase, so too are land-use changes: Newly-constructed wetlands in urban fringe areas are increase mosquito habitat, and efforts to control foxes in those areas have led to increases in wallabies. This is significant because in order to become vectors of the virus, mosquitoes must first bite an infected animal, normally a wallaby or kangaroo.
The Ross River Virus issue is a little different, because it’s an Australian disease that may be increasing its range within that country. The likes of dengue and chikungunya are appearing in countries far from where they have traditionally been found. And a big part of the reason for that is that people have brought them there.
Read more at Discovery News
The site, which spans 23,000 square miles in Patagonia in southern Argentina, came to light this week with the publication of a report in the journal Ameghiniana.
“No other place in the world contains the same amount and diversity of Jurassic fossils,” said geologist Juan Garcia Massini of the Regional Center for Scientific Research and Technology Transfer (CRILAR).
The fossils — between 140 and 160 million years old — lie on the surface because they were recently exposed by erosion, said Garcia Massini, who leads the research team investigating the site.
“You can see the landscape as it appeared in the Jurassic — how thermal waters, lakes and streams as well as plants and other parts of the ecosystem were distributed,” he said.
The fossils were preserved almost immediately, in less than a day in some cases.
“You can see how fungi, cyanobacteria and worms moved when they were alive,” Garcia Massini said of the site that lies along the Deseado Massif mountain range.
Ignacio Escapa of the Egidio Feruglio Paleontology Museum said the researchers had found “a wide range of micro and macro-organisms.”
The fossils are so well preserved, that researchers say each rock extracted from the site could possibly open the door to a new discovery.
From Discovery News
The initial detection of so-called gravitational waves occurred in September when a pair of black holes, each about 30 times more massive than the sun, spiraled in toward each other and then merged into a new, larger black hole more than 1.3 billion light years away.
In a flash, the crash released the equivalent of 50 times the energy of all the stars in the universe, powerful enough to ever-so-slightly jiggle L-shaped, 2.5 mile-long laser beams on Earth that comprise the heart of the Laser Interferometer Gravitational-Wave Observatory, or LIGO.
LIGO observatories in Louisiana and Washington had just been upgraded when the detection was made. Scientists spent months verifying the gravitational waves’ footprint, which changed the length of the laser light arms an amount 10,000 times smaller than the diameter of a proton. Meanwhile, LIGO continued to monitor for other space-shaking cosmic booms.
“Before this, we didn’t even know that black holes existed in pairs,” University of Florida physicist David Reitze, now serving as LIGO director at the California Institute of Technology, told the House Science Committee last week.
“It’s the start of a new astronomy,” added Massachusetts Institute of Technology physicist David Shoemaker.
The LIGO detectors collected data for another three months, then shut down to prepare for an even larger boost in sensitivity.
Additional findings have yet to be released, but Louisiana State University physicist Gabriela González, a spokeswoman for the LIGO Scientific Collaboration, hinted to legislators that the detection of the merging black holes was not a solitary event.
“We saw one event in one month … so we can only predict from that data. But we have taken data for three more months, which we are still analyzing and everything that we see is consistent with what we saw there,” Gonzalez said.
From theoretical models, scientists expect to be able to detect at least a few gravitational wave events per year, she added.
Merging black holes aren’t the cosmic events likely to vibrate the fabric of space and time.
Scientists are hopeful that LIGO will sense the rumblings of neutron stars, which are the dense remnants of collapsed stars so packed with matter that a single teaspoon would weigh 10 million tons.
Typically, neutron stars are magnetized and spinning, though how that works is not fully understood. They also can exist in pairs, giving scientists an opportunity to detect not only gravitational waves set off by their interactions, but X-ray, radio waves and other electromagnetic radiation they produce.
“We can put together all this information … and know more than we could have ever known without gravitational waves or without this combination, this synergy of information,” Shoemaker said.
LIGO also may be able to ferret out supernova explosions, collapsing stars, cosmic strings and even what Shoemaker calls “defects” in the interwoven fabric of spacetime.
“There certainly will be surprises. Every time we open up a new window to the universe, we see new things,” Shoemaker said.
By the time LIGO returns to work late this summer or early fall, it may be joined by the first of several planned laser interferometers outside the United States.
Virgo, a French- and Italian-backed project, located near Pisa in Italy, will add a third ear to detect and verify gravitational waves and pinpoint their source.
Virgo also will serve as a backup if either of twin U.S. LIGO detectors is offline. Having at least two simultaneous detections is key to being able to rule out possible terrestrial sources of vibrations.
Read more at Discovery News
Feb 28, 2016
|Scientists have discovered a new particle -- the latest member to be added to the exotic species of particle known as tetraquarks.|
Quarks are point-like particles that typically come in packages of two or three, the most familiar of which are the proton and neutron (each is made of three quarks). There are six types, or "flavors," of quark to choose from: up, down, strange, charm, bottom and top. Each of these also has an antimatter counterpart.
Over the last 60 years, scientists have observed hundreds of combinations of quark duos and trios.
In 2008 scientists on the Belle experiment in Japan reported the first evidence of quarks hanging out as a foursome, forming a tetraquark. Since then physicists have glimpsed a handful of different tetraquark candidates, including now the recent discovery by DZero -- the first observed to contain four different quark flavors.
DZero is one of two experiments at Fermilab's Tevatron collider. Although the Tevatron was retired in 2011, the experiments continue to analyze billions of previously recorded events from its collisions.
As is the case with many discoveries, the tetraquark observation came as a surprise when DZero scientists first saw hints in July 2015 of the new particle, called X(5568), named for its mass -- 5568 megaelectronvolts.
"At first, we didn't believe it was a new particle," says DZero co-spokesperson Dmitri Denisov. "Only after we performed multiple cross-checks did we start to believe that the signal we saw could not be explained by backgrounds or known processes, but was evidence of a new particle."
And the X(5568) is not just any new tetraquark. While all other observed tetraquarks contain at least two of the same flavor, X(5568) has four different flavors: up, down, strange and bottom.
"The next question will be to understand how the four quarks are put together," says DZero co-spokesperson Paul Grannis. "They could all be scrunched together in one tight ball, or they might be one pair of tightly bound quarks that revolves at some distance from the other pair."
Four-quark states are rare, and although there's nothing in nature that forbids the formation of a tetraquark, scientists don't understand them nearly as well as they do two- and three-quark states.
This latest discovery comes on the heels of the first observation of a pentaquark -- a five-quark particle -- announced last year by the LHCb experiment at the Large Hadron Collider.
Scientists will sharpen their picture of the quark quartet by making measurements of properties such as the ways X(5568) decays or how much it spins on its axis. Like investigations of the tetraquarks that came before it, the studies of the X(5568) will provide another window into the workings of the strong force that holds these particles together.
Read more at Science Daily
|Distribution of dark matter, with a width and height of 350 million light-years and a thickness of 300000 light years. Galaxies are found in the small, white, high-density dots.|
Looking at cosmic microwave radiation, modern satellite observatories like COBE, WMAP and Planck have gradually refined our understanding of the composition of the universe, and the most recent measurements suggest it consists of 4.9% 'normal' matter (i.e. the matter that makes up stars, planets, gas and dust), or 'baryons', whereas 26.8% is the mysterious and unseen 'dark' matter and 68.3% is the even more mysterious 'dark energy'.
Complementing these missions, ground-based observatories have mapped the positions of galaxies and, indirectly, their associated dark matter over large volumes, showing that they are located in filaments that make up a 'cosmic web'. Haider and his team investigated this in more detail, using data from the Illustris project, a large computer simulation of the evolution and formation of galaxies, to measure the mass and volume of these filaments and the galaxies within them.
Illustris simulates a cube of space in the universe, measuring some 350 million light years on each side. It starts when the universe was just 12 million years old, a small fraction of its current age, and tracks how gravity and the flow of matter changes the structure of the cosmos up to the present day. The simulation deals with both normal and dark matter, with the most important effect being the gravitational pull of the dark matter.
When the scientists looked at the data, they found that about 50% of the total mass of the universe is in the places where galaxies reside, compressed into a volume of 0.2% of the universe we see, and a further 44% is in the enveloping filaments. Just 6% is located in the voids, which make up 80% of the volume.
But Haider's team also found that a surprising fraction of normal matter -- 20% -- is likely to be have been transported into the voids. The culprit appears to be the supermassive black holes found in the centres of galaxies. Some of the matter falling towards the holes is converted into energy. This energy is delivered to the surrounding gas, and leads to large outflows of matter, which stretch for hundreds of thousands of light years from the black holes, reaching far beyond the extent of their host galaxies.
Apart from filling the voids with more matter than thought, the result might help explain the missing baryon problem, where astronomers do not see the amount of normal matter predicted by their models.
Read more at Science Daily