Nov 28, 2015

Radar Finds Secret Chamber in King Tut's Tomb

There is a 90 percent chance the tomb of King Tutankhamun contains a hidden chamber, Egypt’s antiquities minister said on Saturday at the end of a three-day probe in the boy king’s burial.

The investigation included for the first time the use of radar scans and focused mainly on the northern wall of the tomb.

“We said earlier there was a 60 percent chance there is something behind the walls. But now after the initial reading of the scans, we are saying now its 90 percent likely there is something behind the walls,” Minister of Antiquity Mamdouh al-Damaty said at a news conference.

The new findings booster a claim by Nicholas Reeves, a British Egyptologist at the University of Arizona, that high-resolution images of the tomb’s walls show “distinct linear traces” pointing to the presence of two still unexplored chambers behind the western and northern walls of the tomb.

“It does look from the radar evidence as if the tomb of Tutankhamun is a corridor tomb and it continues beyond the decorated burial chamber,” Reeves said at the press conference.

Earlier this month infrared thermography, carried out by a team from Cairo University’s Faculty of Engineering and the Paris-based organization Heritage, Innovation and Preservation, showed “differences in the temperatures registered on different parts of the northern wall” of the tomb.

Damati stressed the radar results are preliminary and that a month is needed to analyze the scans.

Carried out by Japanese radar specialist Hirokatsu Watanabe, the radar scans also hint to the presence of a second hidden doorway in the western wall.

According to Reeves, the hidden chamber would contain the remains, and possibly the intact grave goods, of queen Nefertiti, wife of the “heretic” monotheistic pharaoh Akhenaten, Tutankhamun’s father.

Reeves speculated that the tomb of King Tut was not ready when he died unexpectedly at 19 in 1323 B.C., after having ruled a short reign of nine to 10 years. Consequently, he was buried in a rush in what was originally the tomb of Nefertiti, who had died 10 years earlier.

Reeves’s claim about Nefertiti being the occupant of the secret crypt left several experts more than skeptical.

Damati himself believes the hidden chamber may contain the mummy of Kiya, a wife of the pharaoh Akhenaten.

Zahi Hawass, the country’s former antiquities minister, believes there are no hidden tombs at all behind the walls of King Tut’s burial chamber.

“I had already headed an Egyptian excavation mission in the Valley of the Kings and proved that the claim was invalid,” Hawass wrote in the Egypt Independent.

An international team of researchers led by mummy expert Frank Rühli, director of the Institute of Evolutionary Medicine at the University of Zurich, also cautioned last month about the Nefertiti claim.

“Queen Nefertiti might be the already found Younger Lady,” Rühli said.

The “Younger Lady” is a mummy found in 1898 by archaeologist Victor Loret in tomb KV35 in the Valley of the Kings.

Nefertiti is labelled in inscriptions to be Tutankhamun’s mother; genetic analyses identified the “Younger Lady” as the mother of Tutankhamun.

Such evidence would automatically rule out Nefertiti, Rühli and colleagues concluded.

Read more at Discovery News

Alien Megastructure? Probably Not. Exocomets More Likely

Alien megastructure, we hardly knew ye.

After a star’s bizarre appearance sparked news reports earlier this month about extraterrestrial intelligence, a new study suggests it was lowly comet fragments causing the bizarre dimming and brightening spotted by the Kepler space telescope in 2011 and 2013.

The news comes as not that big of a surprise, given that astronomers were already considering comets as an explanation — and that SETI tried pointing a radio antenna at the star and found no signals. But the new study adds that the early data from the Spitzer Space Telescope will need more follow-up to figure out the full story of KIC 8462852′s situation.

Kepler scans stars to look for signs of planets passing in front of them, which causes the stars’ light to dim. But KIC 8462852 had an irregular pattern of brightening and dimming that puzzled astronomers, leading to speculation it was fragments of material from comets, asteroids or planets. Also, some observers in the media said it could be a large alien structure causing the pattern.

Spitzer came in handy because it looks at the universe in infrared light. It’s the perfect set of wavelengths to observe a planet or asteroid because dust glows in infrared. The research team at first used data from NASA’s Wide-Field Infrared Survey Explorer, but the 2010 observations showed little — perhaps because they were done before the Kepler space telescope saw the bizarre signal.

Luckily, Spitzer happened to look at the star this year as part of the normal follow-up procedure for Kepler observations; Spitzer usually looks for dust from planet fragments. Like WISE, the more sensitive Spitzer also saw nothing in infrared wavelengths, so the objects are likely not leaking warm dust from a planetary or asteroid-scale collision. Cold comets, however? A strong possibility.

Read more at Discovery News

Nov 26, 2015

'Material universe' yields surprising new particle

An international team of researchers has predicted the existence of a new type of particle called the type-II Weyl fermion in metallic materials. When subjected to a magnetic field, the materials containing the particle act as insulators for current applied in some directions and as conductors for current applied in other directions. This behavior suggests a range of potential applications, from low-energy devices to efficient transistors.

The researchers theorize that the particle exists in a material known as tungsten ditelluride (WTe2), which the researchers liken to a "material universe" because it contains several particles, some of which exist under normal conditions in our universe and others that may exist only in these specialized types of crystals. The research appeared in the journal Nature this week.

The new particle is a cousin of the Weyl fermion, one of the particles in standard quantum field theory. However, the type-II particle exhibits very different responses to electromagnetic fields, being a near perfect conductor in some directions of the field and an insulator in others.

The research was led by Princeton University Associate Professor of Physics B. Andrei Bernevig, as well as Matthias Troyer and Alexey Soluyanov of ETH Zurich, and Xi Dai of the Chinese Academy of Sciences Institute of Physics. The team included Postdoctoral Research Associates Zhijun Wang at Princeton and QuanSheng Wu at ETH Zurich, and graduate student Dominik Gresch at ETH Zurich.

The particle's existence was missed by physicist Hermann Weyl during the initial development of quantum theory 85 years ago, say the researchers, because it violated a fundamental rule, called Lorentz symmetry, that does not apply in the materials where the new type of fermion arises.

Particles in our universe are described by relativistic quantum field theory, which combines quantum mechanics with Einstein's theory of relativity. Under this theory, solids are formed of atoms that consist of a nuclei surrounded by electrons. Because of the sheer number of electrons interacting with each other, it is not possible to solve exactly the problem of many-electron motion in solids using quantum mechanical theory.

Instead, our current knowledge of materials is derived from a simplified perspective where electrons in solids are described in terms of special non-interacting particles, called quasiparticles, that move in the effective field created by charged entities called ions and electrons. These quasiparticles, dubbed Bloch electrons, are also fermions.

Just as electrons are elementary particles in our universe, Bloch electrons can be considered the elementary particles of a solid. In other words, the crystal itself becomes a "universe," with its own elementary particles.

In recent years, researchers have discovered that such a "material universe" can host all other particles of relativistic quantum field theory. Three of these quasiparticles, the Dirac, Majorana, and Weyl fermions, were discovered in such materials, despite the fact that the latter two had long been elusive in experiments, opening the path to simulate certain predictions of quantum field theory in relatively inexpensive and small-scale experiments carried out in these "condensed matter" crystals.

These crystals can be grown in the laboratory, so experiments can be done to look for the newly predicted fermion in WTe2 and another candidate material, molybdenum ditelluride (MoTe2).

"One's imagination can go further and wonder whether particles that are unknown to relativistic quantum field theory can arise in condensed matter," said Bernevig. There is reason to believe they can, according to the researchers.

The universe described by quantum field theory is subject to the stringent constraint of a certain rule-set, or symmetry, known as Lorentz symmetry, which is characteristic of high-energy particles. However, Lorentz symmetry does not apply in condensed matter because typical electron velocities in solids are very small compared to the speed of light, making condensed matter physics an inherently low-energy theory.

"One may wonder," Soluyanov said, "if it is possible that some material universes host non-relativistic 'elementary' particles that are not Lorentz-symmetric?"

This question was answered positively by the work of the international collaboration. The work started when Soluyanov and Dai were visiting Bernevig in Princeton in November 2014 and the discussion turned to strange unexpected behavior of certain metals in magnetic fields (Nature 514, 205-208, 2014, doi:10.1038/nature13763). This behavior had already been observed by experimentalists in some materials, but more work is needed to confirm it is linked to the new particle.

The researchers found that while relativistic theory only allows a single species of Weyl fermions to exist, in condensed matter solids two physically distinct Weyl fermions are possible. The standard type-I Weyl fermion has only two possible states in which it can reside at zero energy, similar to the states of an electron which can be either spin-up or spin-down. As such, the density of states at zero energy is zero, and the fermion is immune to many interesting thermodynamic effects. This Weyl fermion exists in relativistic field theory, and is the only one allowed if Lorentz invariance is preserved.

The newly predicted type-2 Weyl fermion has a thermodynamic number of states in which it can reside at zero energy -- it has what is called a Fermi surface. Its Fermi surface is exotic, in that it appears along with touching points between electron and hole pockets. This endows the new fermion with a scale, a finite density of states, which breaks Lorentz symmetry.

The discovery opens many new directions. Most normal metals exhibit an increase in resistivity when subject to magnetic fields, a known effect used in many current technologies. The recent prediction and experimental realization of standard type-I Weyl fermions in semimetals by two groups in Princeton and one group in IOP Beijing showed that the resistivity can actually decrease if the electric field is applied in the same direction as the magnetic field, an effect called negative longitudinal magnetoresistance. The new work shows that materials hosting a type-II Weyl fermion have mixed behavior: While for some directions of magnetic fields the resistivity increases just like in normal metals, for other directions of the fields, the resistivity can decrease like in the Weyl semimetals, offering possible technological applications.

Read more at Science Daily

Sensor sees nerve action as it happens

Researchers at Duke and Stanford Universities have devised a way to watch the details of neurons at work, pretty much in real time.

Every second of every day, the 100 billion neurons in your brain are capable of firing off a burst of electricity called an action potential up to 100 times per second. For neurologists trying to study how this overwhelming amount of activity across an entire brain translates into specific thoughts and behaviors, they need a faster way to watch.

Existing techniques for monitoring neurons are too slow or too tightly focused to generate a holistic view. But in a new study, researchers reveal a technique for watching the brain's neurons in action with a time resolution of about 0.2 milliseconds -- a speed just fast enough to capture the action potentials in mammalian brains.

The paper appeared early online in Science.

"We set out to combine a protein that can quickly sense neural voltage potentials with another protein that can amplify its signal output," said Yiyang Gong, assistant professor of biomedical engineering at Duke and first author on the paper. "The resulting increase in sensor speed matches what is needed to read out electrical spikes in the brains of live animals."

Gong did the work as a postdoctoral fellow in the laboratory of Mark Schnitzer, associate professor of biological sciences and applied physics at Stanford, and an investigator of the Howard Hughes Medical Institute. Gong and his colleagues sought out a voltage sensor fast enough to keep up with neurons. After several trials, the group landed on one found in algae, and engineered a version that is both sensitive to voltage activity and responds to the activity very quickly.

The amount of light it puts out, however, wasn't bright enough to be useful in experiments. It needed an amplifier.

To meet this engineering challenge, Gong fused the newly engineered voltage sensor to the brightest fluorescing protein available at the time. He linked the two close enough to interact optically without slowing the system down.

"When the voltage sensing component we engineered detects a voltage potential, it absorbs more light," explained Gong. "And by absorbing more of the bright fluorescent protein's light, the overall fluorescence of the system dims in response to a neuron firing."

The new sensor was delivered to the brains of mice using a virus and incorporated into fruit flies through genetic modification. In both cases, the researchers were able to express the protein in selected neurons and observe voltage activity. They were also able to read voltage movements in different sub-compartments of individual neurons, which is very difficult to do with other techniques.

Read more at Science Daily

The LHC collides ions at new record energy

After the successful restart of the Large Hadron Collider and its first months of data taking with proton collisions at a new energy frontier, the LHC is moving to a new phase, with the first lead-ion collisions of season 2 at an energy about twice as high as that of any previous collider experiment. Following a period of intense activity to re-configure the LHC and its chain of accelerators for heavy ion beams, CERN1's accelerator specialists put the beams into collision for the first time in the early morning of 17 November 2015 and 'stable beams' were declared at 10.59am today, marking the start of a one-month run with positively charged lead ions: lead atoms stripped of electrons. The four large LHC experiments will all take data over this campaign, including LHCb, which will record this kind of collision for the first time. Colliding lead ions allows the LHC experiments to study a state of matter that existed shortly after the big bang, reaching a temperature of several trillion degrees.

"It is a tradition to collide ions over one month every year as part of our diverse research programme at the LHC," said CERN Director General Rolf Heuer. "This year however is special as we reach a new energy and will explore matter at an even earlier stage of our universe."

Early in the life of our universe, for a few millionths of a second, matter was a very hot and very dense medium -- a kind of primordial 'soup' of particles, mainly composed of fundamental particles known as quarks and gluons. In today's cold Universe, the gluons "glue" quarks together into the protons and neutrons that form bulk matter, including us, as well as other kinds of particles.

"There are many very dense and very hot questions to be addressed with the ion run for which our experiment was specifically designed and further improved during the shutdown," said ALICE collaboration spokesperson Paolo Giubellino. "For instance, we are eager to learn how the increase in energy will affect charmonium production, and to probe heavy flavour and jet quenching with higher statistics. The whole collaboration is enthusiastically preparing for a new journey of discovery."

Increasing the energy of collisions will increase the volume and the temperature of the quark and gluon plasma, allowing for significant advances in understanding the strongly-interacting medium formed in lead-ion collisions at the LHC. As an example, in season 1 the LHC experiments confirmed the perfect liquid nature of the quark-gluon plasma and the existence of "jet quenching" in ion collisions, a phenomenon in which generated particles lose energy through the quark-gluon plasma. The high abundance of such phenomena will provide the experiments with tools to characterize the behaviour of this quark-gluon plasma. Measurements to higher jet energies will thus allow new and more detailed characterization of this very interesting state of matter.

"The heavy-ion run will provide a great complement to the proton-proton data we've taken this year," said ATLAS collaboration spokesperson Dave Charlton. "We are looking forward to extending ATLAS' studies of how energetic objects such as jets and W and Z bosons behave in the quark gluon plasma."

The LHC detectors were substantially improved during the LHC's first long shutdown. With higher statistics expected, physicists will be able to look deeper at the tantalising signals observed in season 1.

"Heavy flavour particles will be produced at high rate in Season 2, opening up unprecedented opportunities to study hadronic matter in extreme conditions," said CMS collaboration spokesperson Tiziano Camporesi. " CMS is ideally suited to trigger on these rare probes and to measure them with high precision. "

Read more at Science Daily

Aging star's weight loss secret revealed

VY Canis Majoris is a stellar goliath, a red hypergiant, one of the largest known stars in the Milky Way. It is 30-40 times the mass of the Sun and 300,000 times more luminous. In its current state, the star would encompass the orbit of Jupiter, having expanded tremendously as it enters the final stages of its life.

The new observations of the star used the SPHERE instrument on the VLT. The adaptive optics system of this instrument corrects images to a higher degree than earlier adaptive optics systems. This allows features very close to bright sources of light to be seen in great detail. SPHERE clearly revealed how the brilliant light of VY Canis Majoris was lighting up clouds of material surrounding it.

And by using the ZIMPOL mode of SPHERE, the team could not only peer deeper into the heart of this cloud of gas and dust around the star, but they could also see how the starlight was scattered and polarised by the surrounding material. These measurements were key to discovering the elusive properties of the dust.

Careful analysis of the polarisation results revealed these grains of dust to be comparatively large particles, 0.5 micrometres across, which may seem small, but grains of this size are about 50 times larger than the dust normally found in interstellar space.

Throughout their expansion, massive stars shed large amounts of material -- every year, VY Canis Majoris sees 30 times the mass of Earth expelled from its surface in the form of dust and gas. This cloud of material is pushed outwards before the star explodes, at which point some of the dust is destroyed, and the rest cast out into interstellar space. This material is then used, along with the heavier elements created during the supernova explosion, by the next generation of stars, which may make use of the material for planets.

Until now, it had remained mysterious how the material in these giant stars' upper atmospheres is pushed away into space before the host explodes. The most likely driver has always seemed to be radiation pressure, the force that starlight exerts. As this pressure is very weak, the process relies on large grains of dust, to ensure a broad enough surface area to have an appreciable effect.

"Massive stars live short lives," says lead author of the paper, Peter Scicluna, of the Academia Sinica Institute for Astronomy and Astrophysics, Taiwan. "When they near their final days, they lose alot of mass. In the past, we could only theorise about how this happened. But now, with the new SPHERE data, we have found large grains of dust around this hypergiant. These are big enough to be pushed away by the star's intense radiation pressure, which explains the star's rapid mass loss."

Read more at Science Daily

Nov 25, 2015

Fossils Reveal How Giraffe Got Its Long Neck

Analysis of the neck bones of an extinct member of the giraffe family reveal how today's giraffe got its exceptionally long neck.

It has long been thought that the giraffe's neck was a result of evolution, but fossil evidence had been lacking.

In a paper published in Royal Society Open Science, scientists describe the neck of a "transitional" or "intermediate" species that existed about 7 million years ago.

The findings, by researchers at the New York Institute of Technology, are based on analysis of fossil vertebrae of Samotherium major, a giraffid that roamed parts of Eurasia, including Samos of Greece (where it was originally found and named), South Italy, Turkey, Moldavia, Iran, and China.

The vertebrae were compared with neck bones from the only two living members of the Giraffidae family - the giraffe (Giraffa camelopardalis) and okapi (Okapia johnstoni), a short-necked mammal that lives in central Africa.

Like all mammals, members of the giraffe family have seven bones in their neck.

While today's giraffe's neck is about two meters long, the neck of Samotherium major was about half that length, while the okapi neck is just 60 centimeters long.

Co-author Ms Melinda Danowitz revealed the ancient giraffid's neck was not only intermediate in length, but also in many morphological and proportional features.

"We can finally see the transitional stages in the elongation of the giraffe neck," she said.

Senior author Professor Nikos Solounais, also from the American Museum of Natural History, said the neck was reconstructed from no more than four individuals that were all excavated from Samos in Greece.

"The bones might not be one individual, but considering the rarity of well-preserved fossil necks, it is likely they came from very few individuals, and that several of the bones came from the same individual," he said.

Today's study builds on earlier published work by the team that showed Samotherium underwent the first stage of neck elongation, which involved elongation of the cranial, or front end, of each neck bone.

However the second stage involving elongation of the back end of each neck bone, or the caudal, was not evident.

Ms Danowitz said the Samotherium neck had other characteristics that were also intermediate between the giraffe and okapi.

She said in the okapi the sixth neck bone included a completed ridge on the bone surface known as the ventral ridge.

Read more at Discovery News

King Tut's Tomb: Secret Chamber Search Is On

The search for secret chambers in King Tutankhamun’s tomb will resume tomorrow and will last until Saturday, Egypt’s Minister of Antiquity announced.

The three-day investigation is expected to add new clues to help reveal what Minister of Antiquity Mamdouh al-Damaty called “the discovery of the century.”

“The search will involve the use of radar and infrared thermography,” Damaty told Egypt’s news site Ahram Online.

The new non-invasive probe follows a claim by Nicholas Reeves, a British Egyptologist at the University of Arizona, that high-resolution images of the tomb’s walls show “distinct linear traces” pointing to the presence of two still unexplored chambers behind the western and northern walls of the tomb.

According to Reeves, one chamber contains the remains, and possibly the intact grave goods, of queen Nefertiti, wife of the “heretic” monotheistic pharaoh Akhenaten, Tutankhamun’s father.

Reeves speculated that the tomb of King Tut was not ready when he died unexpectedly at 19 in 1323 B.C., after having ruled a short reign of nine to 10 years. Consequently, he was buried in a rush in what was originally the tomb of Nefertiti, who had died 10 years earlier.

Reeves and Damaty conducted a preliminary visual inspection of the tomb in September. The investigation was followed earlier this month by further tests, carried out by a team from Cairo University’s Faculty of Engineering and the Paris-based organization Heritage, Innovation and Preservation.

The researchers used infrared thermography to detect the temperature of the walls in the tomb.

According to Damaty, the analysis showed “differences in the temperatures registered on different parts of the northern wall” of the tomb.

Read more at Discovery News

How Terrorism Can Harm Your Brain

When ISIS terrorists attacked Paris on Nov. 13, they took 130 lives and wounded hundreds more. But their bloody acts may have injured far more people -- both survivors and the countless numbers who experienced the event vicariously through horrific media images -- in an insidious way, by causing potentially harmful changes in their brains.

Indeed, terrorism's effect on the brain is so powerful that those who survive attacks have significantly higher rates of post-traumatic stress disorder than those who make it through accidents or natural disasters. But terrorism also is linked to long-term problems such as anxiety and alcohol abuse in people who only have secondhand exposure to the event by watching it on television.

Recent research shows fear of future terrorist attacks can alter brain chemistry in a way that increases your risk of dying eventually from a heart attack or other ailments that might seem unrelated to the violence.

The latter study, published in 2014 in Proceedings of the National Academy of Sciences, looked at more than 17,000 Israelis, who live in a country where terrorist attacks are a frequent occurrence.

The subjects who had the most fear of terrorism tended to have resting heart rates that were 10 to 20 beats per minute faster than the norm, an indicator of increased risk for heart attacks and strokes. The elevated heart rate was linked to a change in brain chemistry. Blood tests revealed a decline in the function of acetylcholine, a neurotransmitter involved in responses to stress and which acts as a brake to the inflammatory response.

"Our brain reacts to acute stress situations by a rapid burst of acetylcholine release," explained study co-author Hermona Soreq, a professor of molecular neuroscience at the Edmond and Lily Safra Center for Brain Sciences at Hebrew University in Jersusalem.

"The brain sends the acetylcholine to body tissues through the vagus nerve; Since acetylcholine blocks inflammation responses, too much of it weakens the immune system. We found lower prospects to survive in patients after heart attack whose blood tests show weakened capacity to destroy acetylcholine."

Soreq said that terrorism-induced anxiety also causes the production of small molecules called microRNAs, which block the function of numerous other genes, and can alter regulation of the nervous system.

Terrorism triggers mechanisms hard-wired into the nervous system by evolution, which enabled our ancient ancestors to escape from animal predators and rival human clans. The human brain and vision system is fine-tuned to spot things that we should be afraid of, and then react to them in a flash -- even without consciously realizing it.

In a 2012 study, for example, researchers from the University of Edinburgh and New York University trained subjects to fear certain pictures by giving them mild shocks. Some subjects were allowed to look directly at the images, while others only got to glimpse them in one eye while researchers flashed a colorful image in the other eye to interfere with conscious perception.

Even with that hindrance, the subjects who got the one-eyed glimpse actually developed a fear response more quickly.

When a person spots danger -- say, a gunman who bursts into a theater -- the alarm is sounded in the amygdala, a sort of biological alarm system that triggers the body's response. It directs glands to release an array of chemicals such as adrenalin and cortisol, which shift the heart, lungs and muscles into high gear. The senses shift into narrowly focused hyper-awareness of information that might aid in survival.

A study published in Psychological Science in 2009, for example, found that fear made subjects see coarser lines, which help the brain to evaluate movement and distance, more clearly, while they couldn't make out fine lines as well as usual.

After a threat is over, in many cases, a survivor's brain gradually can shift back into normal operating mode. But not always. Studies have shown that between 28 and 33 percent of survivors of mass shootings and 34 percent of bombing survivors develop post-traumatic stress disorder -- far higher rates than people involved in terrifying accidents or natural disasters.

Survivors continue to relive the trauma and often suffer from symptoms such as irritability, difficulty concentrating, hypervigilant watchfulness, and an exaggerated startle response, and sometimes feelings of numbness.

Recent research by German scientists suggests that cortisol, one of the chemicals that the body releases in an effort to survive a terror attack, not only helps burn the event more vividly into a person's memory, but also helps to keep it vivid even after it is retrieved repeatedly.

But it's not only immediate survivors whose brains may be affected by terrorism. A study published in the New England Journal of Medicine in 2001 found that after the 9-11 attacks, 44 percent of U.S. adults and 35 percent experienced one or more substantial symptoms of stress, such as difficulty concentrating, repeated memories or dreams of the event, irritation and angry outbursts. The level of stress that people experienced was linked to the extent that they had watched TV coverage of the attacks.

Those effects sometimes last for years. Another study, published in 2008 in Journal of the American Public Health Association, looked at the effect of 9-11 on the mental health of office workers in Chicago, far away from the actual site of the attacks in New York and Washington.

Read more at Discovery News

Einstein's General Relativity Still Put to Test

A century after Albert Einstein unveiled a new concept to explain gravity, his so-called general relativity theory remains fertile ground for scientific observations and experiments.

Einstein’s revolutionary idea stemmed from his special theory of relativity, published a decade earlier, which wed space and time into a single continuum known as spacetime. Observers at different locations, for example, would see the same star exploding at different times, depending on how far away they were from the event. What is constant is the speed of light.

Special relativity did not take into account gravitational effects. Einstein toiled another 10 years to understand the physics and work through the math before unveiling his radically new idea in a four-part lecture at the Prussian Academy of Sciences that culminated on Nov. 25, 1915. Einstein published “The Field Equations of Gravitation” paper a week later.

“Before Albert Einstein came up with his general theory of relativity, we sort of pictured gravity as this magical force that connected different masses with one another,” said NASA astrophysicist Ira Thorpe, with the Goddard Space Flight Center in Greenbelt, Md.

Under Issac Newton’s theory of gravity, which had dominated physics for more than 200 years, if a mass in one part of the universe moved, all the other masses in the rest of the universe would instantly know and be affected by the motion.

That concept, however, ran counter to an implication of Einstein’s special relativity theory, which established a universal speed limit -- the idea that nothing can move faster than the speed of light.

Say one day the sun disappeared. Under Newtonian physics, the effect would be felt immediately on Earth. Under Einstein’s theory, it would take roughly eight minutes – the time it takes both light waves and gravitational waves, which also travel at the speed of light -- to cover the 93 million miles between Earth and the now-vanished sun.

Rather than masses exerting gravitational forces on one another, Einstein realized that it was spacetime itself that was bending, similar to what happens when a bowling ball rolls across a trampoline.

One of the newest frontiers opened by general relativity is the search for gravitational waves, a rippling of spacetime caused by massive objects in motion.

“They’re waves, much like water waves or light or any other kind of electromagnetic radiation, except here what’s ‘waving’ is space and time itself,” Thorpe said during a webcast panel discussion hosted by

Just like a bowling ball warps a trampoline more than a baseball, massive objects, such as black holes, bend spacetime more than relatively puny objects, like the sun.

“There’s a whole spectrum of gravitational waves, just like there’s a whole spectrum of electromagnetic waves. So, just like you have radio and infrared and visible and ultraviolet and X-ray and all the way up through gamma ray, you have the same type of thing with gravitational waves,” Thorpe said.

Though astronomers have not detected any gravitational waves yet, they know what frequencies and wavelengths different sources generate, thanks to computer modeling.

The longest gravitational waves were produced in the Big Bang explosion 13.8 billion years. “They get stretched out to the size of the universe as the universe expands. They kind of expand along with the universe,” Thorpe said.

Some scientists are studying the remnant cosmic microwave background radiation for telltale fingerprints of gravitational waves. Others have been hunting for gravitation waves set off by massive, fast-moving objects, such as binary black holes.

Unlike most electromagnetic telescopes, which have to be pointed, gravitational wave detectors are more like microphones that you just stick out and see what’s there, Thorpe said.

“You get sources from all directions and then you do data analysis to disentangle them,” he said.

Read more at Discovery News

Nov 23, 2015

Animal That Survives in Space Has Weird DNA

The only animal known to survive the extreme environment of outer space without the help of special equipment turns out to have the most foreign DNA of any species.

Water bears, also known as tardigrades, have genomes that are nearly one-sixth foreign, meaning that the DNA comes from creatures other than the animal itself, new research finds.

The discovery, published in the Proceeding of the National Academy of Sciences, adds to the evidence that tiny water bears are incredibly unique and seemingly indestructible animals. In 2007, some were even rocketed into space on the outside of a satellite.

When the satellite returned, many of the water bears were still alive. What’s more, some of the females had laid eggs in space, with the young hatching healthily, as though nothing had happened.

“We had no idea that an animal genome could be composed of so much foreign DNA,” co-author Bob Goldstein of the University of North Carolina at Chapel Hill said in a press release. “We knew many animals acquire foreign genes, but we had no idea that it happens to this degree.”

Water bears are segmented, eight-legged micro-animals that measure just a miniscule fraction of an inch long. Goldstein, lead author Thomas Boothby and their team determined that water bears acquire 6,000 foreign genes primarily from bacteria, but also from plants, fungi and various single-celled microorganisms.

This means that 17.5 percent of the water bear’s genome comes from these other sources.

The DNA is acquired via a process called horizontal gene transfer. Instead of just inheriting DNA, it is swapped between species.

Boothby said, “Animals that can survive extreme stresses may be particularly prone to acquiring foreign genes — and bacterial genes might be better able to withstand stresses than animal ones.”

Water bears have astounded scientists for years with their heartiness. For example, you can stick them in a freezer for a year. Within 20 minutes, the animal thaws out and starts to scurry around as normal.

The researchers suspect that when water bears are under conditions of extreme stress, such as desiccation, their DNA will break into small pieces. When the cell rehydrates, the cell’s membrane and nucleus (where the DNA resides) become temporarily “leaky,” such that DNA and other large molecules can pass through easily.

During this process, the water bears not only repair their own damaged DNA, but also stitch in the foreign DNA, creating a mosaic of genes that come from different species.

The prior record holder for most foreign DNA was another microscopic animal called the rotifer. It is now known that rotifers just have about half as much foreign DNA as water bears, though.

Read more at Discovery News

Captivating Blue Dragon Sea Slug Washes Up in Australia

It takes a lot of courage to go up against the venomous Portuguese man o' war -- a creature that sends even humans bolting out the water -- but the blue dragon is up for the challenge.

As it munches on the highly venomous siphonophore, the blue dragon intentionally eats the man o' war's toxic stingers, storing them within its own body. Now armed and dangerous with its victim's weapon, the blue dragon can impart a nasty sting on any would-be predators.

Also known as Glaucus atlanticus, the small sea slug is found floating along the surface many of the world's oceans, yet rarely seen by humans -- unless it washes ashore, as one did on Australia's Gold Coast earlier this week:

Griffith University marine invertebrates expert Kylie Pitt told the Gold Coast Bulletin that the "really weird" creatures "float upside down and move around using the water's surface tension."

"I have handled them before and wasn't stung, but I would not recommend anyone pick them up because they can have a painful sting," he added.

From Discovery News

Medieval Parchment Mystery Solved

Using a simple PVC eraser, an international team of researchers has solved the long-standing mystery surrounding the origin of the tissue-thin parchment used to produce the first pocket Bibles in the Middle Ages.

The secret of the ultra-thin material derives from a highly specialized craft technique rather than the supply of particular animal skins, said the researchers.

More than 20,000 copies of pocket Bibles were produced by scribes in the 13th century, mainly in France but also in England, Italy and Spain.

The books were written on an ultra-fine, almost translucent parchment known as “uterine vellum.” It was believed to have come from the thin skins of unborn calves or sheep.

But most paleographers have discounted the theory, viewing the Medieval uterine vellum simply as a myth.

“Its production on the scale implied by extant manuscripts would have entailed an untenably high number of aborted fetuses,” researchers led by Sarah Fiddyment and Matthew Collins of the BioArCh research facility in the Department of Archaeology at York, wrote in Proceedings of the National Academy of Sciences (PNAS).

Older research suggested smaller, more thin-skinned mammals such as rabbit, squirrel or even rats as the source of the unique writing material.

To identify the animal origin of parchment, the researchers used a novel, non- invasive technique – a triboelectric extraction of skin collagen.

A variant on ZooMS (ZooArchaeology by Mass Spectrometry) peptide mass fingerprinting, the simple method extracts protein from the parchment surface simply by rubbing a PVC eraser on the membrane surface.

“By passing the eraser gently across the surface, you generate an electrostatic charge — in the same way you can rub a silk cloth on amber or a balloon on your hair,” Matthew Collins told Discovery News. “The eraser exfoliates into charged sheets, and the protein and dirt are lifted off onto the resulting crumbs,” he added.

Using this method, Collins and colleagues analyzed 72 pocket Bibles originating in France, England, and Italy and 293 additional parchment samples from the 13th century.

The thickness in the parchment samples ranged from 0.03 to 0.28 mm.

“We found no evidence of unexpected species, such as rabbit or squirrel. However, we did identify the use of more than one mammal species in a single manuscript, consistent with the local availability of hides,” the researchers wrote.

According to Collins and colleagues, parchment makers simply had the skills to make the finest parchments from calf, goat and sheep skins.

“It is more a question of using the right parchment-making technology than using uterine skin,” said co-author and parchment conservator Jiří Vnouček.

Based on the new findings, Vnouček has recreated parchment similar to uterine vellum from old skins.

Read more at Discovery News

Lost Ancient Greek Island May Have Been Found

An international team of archaeologists believe they had discovered an island in the Aegean Sea that was once the ancient city of Kane, site of an epic sea battle between the Athenians and the Spartans in 406 B.C.

The Arginusae islands, now called the Garip islands, lie only a few hundred yards off the coast of Turkey, National Geographic reported Friday. Ancient historical sources refer to three Arginusae islands but the exact location of the third has long been unclear, disappearing from maps as far back as the 16th century.

Researchers determined what is now a peninsula was once an island after drilling into the ground and examining rock samples, the magazine reported.

The Athenians crushed the Spartans in the battle of Arginusae, but the victory was short-lived.

A storm stranded Athenians whose ships had been destroyed, according to the magazine. When the victorious admirals returned home, the citizens of Athens voted to execute them for failing to rescue those left behind.

The archaeological team drilled down into the filled-up gap that once separated Kane from the Turkish coast to discover that it was made up of loose soil and rock, ScienceAlert reported.

“It had been a matter of discussion if the islands here were the Arginus Islands or not until our research began,” one of the team, archaeologist Felix Pirson from the German Archaeology Institute, told the Dogan News Agency, according to the website.

“But then we revealed that the ancient Kane was located on an island in the past,” he said. “The strait between this island and the land was filled with alluviums and created this peninsula. We will get more evident information after examining the geological samples.”

From Discovery News

Mars Will Become a Ringed Planet When Phobos Dies

Mars’ doomed moon Phobos may leave its parent planet a parting gift. A new study shows the moon is likely to break apart before it hits the atmosphere, creating a debris ring that will encircle Mars for millions of years.

The research, published in this week’s Nature Geoscience, follows a report earlier this month that not only is Phobos losing altitude due to Mars’ gravity, it also already is showing signs of structurally stress from tidal forces.

Phobos survived a giant impact early in its history, but damage from the crash left the moon weak, say Benjamin Black and Tushar Mittal, planetary scientists with University of California at Berkeley.

Their study shows that in 20 million to 40 million years, Phobos will break apart, leaving a cloud of debris that will relatively quickly assembly into a ring around Mars.

Initially, the ring will be as dense as Saturn’s rings today, and it will last for up to 100 million years, the study shows.

For Earthlings, Phobos’ demise presents a unique opportunity to study what may be the solar system’s last inwardly migrating moon.

“Inwardly migrating satellites — some of which may break up tidally, some of which may collide with their primaries — are likely to be an under-appreciated and important component of planetary evolution,” the authors note.

“Phobos offers the last possible glimpse of the signatures and processes that applied to inwardly migrating moons and the interplay with ring formation early in our solar system’s history.”

From Discovery News

Nov 22, 2015

Syphilis widespread in Central Europe even before Columbus' voyage to America

In 1495, a "new" disease spread throughout Europe: syphilis. Christopher Columbus was said to have brought this sexually transmitted disease back from his voyage to America. At least, that has been the accepted theory up until now. Using morphological and structural evidence, researchers from the Department of Forensic Medicine and the Center for Anatomy and Cell Biology (bone laboratory) at MedUni Vienna have now identified several cases of congenital syphilis dating back to as early as 1320 AD in skeletons from excavations at the cathedral square of St. Pölten, Austria "The discovery clearly refutes the previous theory," say study leaders Karl Großschmidt and Fabian Kanz of MedUni Vienna.

Congenital syphilis, which is passed from a pregnant mother to her unborn child, was primarily identified by changes to the teeth of skeletons from the 14th century. "We found so-called Hutchinson's teeth with central notches and converging edges and mulberry molars, which are characteristic signs of syphilis," study authors Kanz and Großschmidt (Department of Cell and Developmental Biology) explained. Their findings have now been published in the Journal of Biological and Clinical Anthropology.

Thin sections of bones provide perfect examination results

The researchers at the Center for Anatomy and Cell Biology of the Medical University of Vienna prepared undecalcified bone thin sections from the bones and teeth of the skeletons for histological examination and analysis. These thin sections, which can only be produced in a few places throughout the world, where subsequently examined by a special light microscopy technique to morphologically determine the pathogen involved.

Up to now, a total of 9000 skeletons as old as the 9th century AD have been recovered from the excavations in the cathedral square in St. Pölten. The large number of unearthed individuals at one archaeological site is unique in Europe. The recovery was conducted in close collaboration with the Urban Archaeology Department of the state capital of Lower Austria. Additional studies of the living conditions and diseases evident from the skeletons were started.

This remarkable discovery of the earliest evidence of syphilis between 1320 and 1390 now awaits confirmation by molecular biological tests and proteomics (examination of the proteome using biochemical methods). The scientists hope to gain further insights from the proteomic analysis, in particular, because the DNA of syphilis decays very rapidly.

From Science Daily

'Resurrection Plants' Offer Hope as Climate Turns Hostile

As the race to adapt to climate change quickens, a South African scientist is leading global research into developing crops that mimic the extraordinary survival skills of “resurrection plants.”

Jill Farrant, a professor of molecular and cell biology at the University of Cape Town, hopes that unlocking the genetic codes of drought-tolerant plants could help farmers toiling in increasingly hot and dry conditions.

With more than 130 known varieties in the world, resurrection plants are a unique group of flora that can survive extreme water shortages for years.

During a drought, the plant acts like a seed, becoming so dry it appears dead.

But when the skies finally open and the rain pours down, the shriveled plant bursts “back to life”,  turning green and robust in just a few hours.

“I want to cater to the subsistence farmer, the person who wants to make enough food to live,” Farrant, 55, said. “Farmers are becoming more and more dispirited, and droughts are killing them.”

Perhaps the most well-known resurrection plant is Myrothamnus flabellifolius, which makes antioxidant chemicals to protect it during dry spells and is used in fashion designer Giorgio Armani’s cosmetics line.

- A life passion -

A farmer’s daughter, Farrant recalls stumbling across a resurrection plant as a nine-year-old and being amazed at its seemingly immortal properties.

“I wrote in my diary about a plant that had died and came back after the rain,” she said.

She returned to the subject professionally in 1994, and has since become the world’s leading expert in her field.

Environmentalists fear that more and more of Africa will be reduced to a dust bowl by global warming, with higher temperatures, reduced water supplies and population growth threatening to trigger worsening famines.

Climate change could reduce maize yields across southern Africa by as much as 30 percent by 2030, according to the UN Environment Programme.

Ahead of the United Nations conference in Paris at the end of November, countries are facing growing pressure to keep global warming below two degrees Celsius (3.6 degrees Fahrenheit) above pre-Industrial Revolution levels by weaning their carbon-hungry societies off fossil fuels.

But, scientists say it is just as important to adapt to the new reality.

“Soil, cropping systems, farming systems — they all must have the capacity to recover from a drastic change in climate,” said Rattan Lal, professor of soil science at Ohio State University.

“We should make agriculture part of the solution to our issues… the climate change problem is so huge everything should be on the table.”

If successful, Farrant will follow in the venerable footsteps of earlier scientists who have saved crops from devastation by exploiting plants with specific strengths.

In the 1970s, US maize was rescued from southern leaf blight disease by incorporating resistant genes found in other varieties of maize.

- Adapt to survive -

Farrant has recently focused her research on teff, a grass native to Ethiopia whose seed has been used as a stable food in the region for centuries.

She hopes to make it more resilient by activating genes she discovered by studying resurrection plants.

“My main aim all along is to make crops that can improve drought tolerance,” Farrant said. “If we get the money, I would say in 10 to 15 years we’ve got a product.”

Experts warn that drought-tolerant crops are not a one-stop solution to the world’s climate problems or even a safeguard against hunger.

Read more at Discovery News