Mystery of Volcano Lightning Explained

When Mt. Vesuvius erupted in the year 79, famously burying the town of Pompeii in ash, historian Pliny the Younger recorded that the volcano expelled “frightening dark clouds, rent by lightning twisted and hurled, opening to reveal huge figures of flame.” It was the first description of a phenomenon that, almost 2,000 years later, is the stuff of viral Internet photos: lightning that arcs its way through the ash plumes of some volcanic eruptions.

It’s a phenomenon that has, however, puzzled scientists, who have wondered exactly how such lightning is generated. Two new papers, published in Geophysical Research Letters, the journal of the American Geophysical Union (AGU), have helped provide clarity and, in the process, unify two competing schools of thought. (Yes, there are competing schools of thought on volcanic lightning.)

The basics of lightning are understood well enough: Particles within a cloud become electrified, generating a field in which positive and negative charges are separated, and the lightning restores the charges to balance. In thunderstorms, ice crystals are the particles that are electrified. What was unknown was whether ice was also required for volcanic lightning, or whether friction between particles of ash performed that role. The new studies show that both can be true, depending on the situation.

In one study, Alexa Van Eaton, a volcanologist at the U.S. Geological Survey Cascades Volcano Observatory in Vancouver, Wash., and colleagues analyzed lightning during the April 2015 eruption of the Calbuco volcano in Chile, using a global network of lightning sensors.

They found that, far downwind of the volcano, lightning followed the movements of the very top of the ash plume where it was cold enough for ice crystals to develop.

“The lightning basically decoupled from all the other ash particles that were falling to the ground,” said Van Eaton. “Instead, they seem to follow the ice crystals that stayed high in the atmosphere.”

So, mystery solved, right? Ice is after all required for volcanic lightning? Not so fast. Because Van Eaton and her team found that lightning also occurred during a second stage of the eruption, when ash and gas flowed close to the ground, far away from any ice crystals, suggesting that the collision of ash particles alone can create enough of a charge.

That latter finding was reinforced by the second study, in which a team led by Corrado Cimarelli, a volcanologist at Ludwig Maximilian University in Munich, Germany, recorded high-speed video observations of volcanic lightning at Sakurajima volcano on the island of Kyushu, Japan, which has been erupting persistently since 2009. Because ash plumes can obscure the lightning that is taking place within them, Cimarelli and his team also included data from nearby acoustic sensors and electromagnetic field measurements.

They found that during an explosion, particles of ash and debris rub up against each other, which creates a build-up of electrical charge. “Where there is ash violently ejected in the atmosphere, there will be electrical discharges, independent of the magnitude of the eruption,” said Cimarelli.

Read more at Discovery News

Death and Taxes: Musings On Certainty

Tax day is April 18 this year. It’s an annual event greeted with groans and occasionally panic across the country. ”In this world nothing can be said to be certain, except death and taxes,” Benjamin Franklin wrote in a 1789 letter.

Franklin wasn’t lamenting having to pay his taxes. Instead, prior to that passage, Franklin expressed his concerns about the durability of the Constitution, and it makes sense that a scientist would harbor a sense of uncertainty about the document that would guide the major political experiment that was the fledgling republic.

In the sciences, a sure thing is elusive; uncertainty is the norm.

Scientific research is an iterative process. A hypothesis is formulated; research is undertaken; evidence is gathered; results are analyzed. Uncertainty doesn’t mean a lack of understanding so much as it provides opportunities for further study.

As the Union of Concerned Scientists, a scientific advocacy organization, explains in an article about climate change: “To most of us, uncertainty means not knowing. To scientists, however, uncertainty is how well something is known.”

Scientists express their degree of certainty by presenting qualified conclusions based on their results, explaining potential limitations of their methodology and shining a light on potential sources of error for the sake of transparency. Scientific findings have to be reproducible to be reliable, but even that isn’t exactly proof of a theory.

“The very expression ‘scientifically proven’ is a contradiction in terms,” physicist Carlo Rovelli said in a 2012 interview. “There is nothing that is scientifically proven.”

Certainty is described in terms of confidence, and scientists have their own terminology for explaining their level of assurance in their findings. Take the 2012 discovery of the Higgs boson, an elementary particle in the Standard Model of physics first theorized in the 1960s, also known as the “god particle.”

“We observe in our data clear signs of a new particle, at the level of five sigma, in the mass region around 126 GeV,” Fabiola Gianotti, spokeswoman for the Atlas experiment at the LHC, said upon the discovery of the Higgs.

Five sigma is the confidence level required by particle physicists to claim a new discovery, and represents a 1-in-3.5 million probability that the observation is the result of random chance rather than a real effect.

Certainty and probability are related but not necessarily interchangeable terms. Certainty deals with confidence surrounding the facts; probability concerns the likelihood of a particular outcome.

The Intergovernmental Panel on Climate Change (IPCC), for example, uses different terminology to distinguish between facts and forecasts. A statement with a nine out of 10 chance of being true would be described as “very high confidence,” while an outcome with a 90 percent chance of occurring is “very likely.”

Improbable or outlier events don’t necessarily reflect a lack of certainty on the part of the scientists who study them.

To provide a handful of scenarios: There is a 12 percent chance in the next decade that Earth will be hit by a megaflare that causes trillions of dollars in damage.

The Cascadia fault line in the Pacific Northwest has a one-in-three chance of experiencing a major catastrophic earthquake in the next 50 years.

The probability of a caldera-forming eruption at Yellowstone stands around 1 in 730,000 or 0.00014 percent.

The degree of certainty in each of these cases depends on the methodology used and measurements taken by the scientists responsible for the forecasts.

Read more at Discovery News

Model Solves Mystery of Monarch Butterfly Migration

Scientists think they have modeled the brain mechanisms that let monarch butterflies, year after year, migrate thousands of miles in one direction: south, to Mexico.

While researchers already knew from prior analyses that the winged wonders use two primary bits of input data to navigate – time of day and position of the sun on the horizon – they had no answer for how the butterfly’s brain gathers and processes that information.

Until now, say researchers from the universities of Washington, Michigan and Massachusetts.

In a paper published in the journal Cell Reports, a team from those institutions says it has modeled the neural control mechanisms at work in the butterfly’s brain.

“We wanted to understand how the monarch is processing these different types of information to yield this constant behavior — flying southwest each fall,” said study co-author Eli Shlizerman, an assistant professor at the University of Washington, in a statement.

Monarchs watch the sun, but that’s not enough to get them where they need to go. They also need the time of day. Monarchs, just like people, have a kind of internal clock that keeps track of the daily go-round. Unlike people, though, their clock is centered in the antennae (an appendage humans have so far disdained).

Shlizerman and his colleagues recorded neural signals coming from monarch antenna nerves, to keep track of the clock information, as well as information coming from the insect’s eyes, to account for sun position.

Then they used that data to create a circuit model to show the neural control mechanisms – for the “clock” and “sun position” – that help the butterfly point itself southwest.

The scientists’ model even accounts for how the butterflies get back on course if they stray.

Read more at Discovery News

Cosmic Ray Tech May Unlock Pyramids' Secrets

A new generation of muon telescopes has been built to detect the presence of secret structures and cavities in Egypt’s pyramids, a team of researchers announced on Friday.

Built by CEA (French Alternative Energies and Atomic Energy Commission) the devices add to an armory of innovative, non-destructive technologies employed to investigate four pyramids which are more than 4,500 years old. They include the Great Pyramid, Khafre or Chephren at Giza, the Bent pyramid and the Red pyramid at Dahshur.

The project, called ScanPyramids, is scheduled to last one year and is being carried out by a team from Cairo University’s Faculty of Engineering and the Paris-based non-profit organization Heritage, Innovation and Preservation (HIP Institute) under the authority of the Egyptian Ministry of Antiquities.

International researchers from Nagoya University and KEK (High Energy Accelerator Research Organization) in Japan and Laval University, Quebec, Canada, have also joined the project, which is separate from the search for the secret room in King Tut’s tomb.

“Now we welcome new researchers from the Irfu, a CEA fundamental research team,” Mehdi Tayoubi, co-director of the ScanPyramids mission with Hany Helal, professor at Cairo University’s Faculty of Engineering and former minister of research and higher education, said.

Irfu, which stands for Institute of Research into the Fundamental Laws of the Universe, gathers almost 800 researchers on astrophysics, nuclear physics and particle physics.

“These scientists have built dedicated muon telescopes for our mission. They are actually under construction and being tested in the CEA laboratories at Saclay, France,” Tayoubi told Discovery News.

“It is really exciting to see how a technology that just came out from a fundamental research laboratory can help us understand 4,500-year-old massive monuments with non visible physics particles,” he added.

The new muon devices rely on micro-pattern gas detectors called Micromegas. Extremely precise, they are used to reconstruct particles tracks in high energy physics. For example, CEA’s Micromegas have been installed in the Thomas Jefferson National Accelerator Facility.

Such muon telescopes will be used in addition to the infrared thermography, muon radiography, and 3-D reconstruction technologies that have already been employed to investigate the pyramids.

So far the researchers have detected striking thermal anomalies on the eastern and northern side of the Great Pyramid at Giza, which could possibly indicate an unknown cavity or internal structure.

A team led by specialist Kunihiro Morishima, from the Institute for Advanced Research of Nagoya University, Japan, installed 40 muon detector plates inside the lower chamber of the Bent pyramid at Dahshur in an attempt to capture cosmic particles.

The technology relies on the muons that continually shower the Earth’s surface. They emanate from the upper layers of Earth’s atmosphere, where they are created from collisions between cosmic rays of our galactic environment and the nuclei of atoms in the atmosphere.

“Just like X-rays pass through our bodies allowing us to visualize our skeleton, these elementary particles, weighing around 200 times more than electrons, can very easily pass through any structure, even large and thick rocks, such as mountains,” Tayoubi said.

Plate detectors placed inside the pyramid allow researchers to discern void areas — these are places where muons cross without problem — from denser areas where some muons are absorbed or deflected.

While the Japanese muon detectors are used inside the pyramids, the new moun telescopes, using gas detectors, will be used outside the pyramids.

Read more at Discovery News

Ancient Mass Graves Discovered in Greece

Archaeologists have discovered two mass graves near the Greek capital containing the skeletons of 80 men who may have been followers of ancient would-be tyrant Cylon of Athens.

Regional archaeological services director Stella Chryssoulaki laid out the theory Thursday as she unveiled the findings at the Central Archaeological Council, the custodians of Greece’s ancient heritage.

Given “the high importance of these discoveries”, the council is launching further investigations, the culture ministry said in a statement.

Two small vases discovered amongst the skeletons have allowed archaeologists to date the graves from between 675 and 650 BC, “a period of great political turmoil in the region”, the ministry said.

The skeletons were found lined up, some on their backs and others on their stomachs. A total of 36 had their hands bound with iron.

They were discovered during excavations at an ancient cemetery on Athens’ seaside outskirts, on the construction site of the new National Library of Greece and National Opera.

Archaeologists found the teeth of the men to be in good condition, indicating they were young and healthy.

This boosts the theory that they could have been followers of Cylon, a nobleman whose failed coup in the 7th century BC is detailed in the accounts of ancient historians Herodotus and Thucydides.

Cylon, a former Olympic champion, sought to rule Athens as a tyrant. But Athenians opposed the coup attempt and he and his supporters were forced to seek refuge in the Acropolis, the citadel that is today the Greek capital’s biggest tourist attraction.

Read more at Discovery News

Ancient Peruvian Mystery Solved From Space

Satellite observations may have unraveled a mystery surrounding a series of unique and ancient structures in southern Peru.

The desert area of Nazca is most famous for giant representations of humans, animals and plants — as well as 900 geometric shapes — carved into the ground: the so-called Nazca lines. But the lines are not the only artifacts of the Nazca civilization, which flourished in the area between 200 BC and 600 AD. The region also contains spiraling, rock-lined holes, known as puquios. Long understood to be a series of underground aqueducts, little else is known about them.

But now, Rosa Lasaponara and a team from the Institute of Methodologies for Environmental Analysis in Italy believe they have some answers. Using satellite imagery, they were able to better understand how the puquios were distributed across the Nazca region.

By considering their positioning relative to water resources and to settlements, they were able to piece together a picture of just how extraordinarily advanced the puquio system was. The corkscrew-shaped tunnels, Lasaponara concluded, funneled wind into a series of underground canals, forcing water to places in the arid region where it was needed.

“The puquios were the most ambitious hydraulic project in the Nasca area and made water available for the whole year, not only for agriculture and irrigation but also for domestic needs,” she told the BBC. “Exploiting an inexhaustible water supply throughout the year, the puquio system contributed to an intensive agriculture of the valleys in one of the most arid places in the world.”

The puquios’ construction, added Lasaponara, “involved the use of particularly specialized technology,” and their maintenance “was likely based on a collaborative and socially organized system, similar to that adopted for the construction of the famous ’Nazca lines‘ which in some cases are clearly related to the presence of water.”

Indeed, one recent theory posits that the lines are in effect a map, pointing to puquios’ locations. As much attention as the lines have deservedly received worldwide over the decades, perhaps it is the puquios that made those lines, and indeed the Nazca civilization, possible.

From Discovery News

Europa's Deforming Ice Is a Surprising Heat Generator

As excitement builds for NASA’s Juno mission that will enter Jupiter orbit this summer, and future missions that will investigate ice moon Europa’s life-supporting potential, new research into the strange qualities of the moon’s cracked crust could reveal some fascinating science about Europa’s sub-surface ocean.

Researchers of Brown University in Providence, R.I., have melded observations of Europa with computer models and laboratory experiments to reveal the tidal compression caused by Jupiter’s hefty gravitational field could cause the moon’s fragmented ice to generate more heat than thought, creating exciting new implications for the search for Europan life.

Before NASA’s Voyager and Pioneer flyby missions in the 1970s and then the Galileo mission in the 1990s, we had little clue about the dynamic nature of the Jovian satellites. “(Scientists) had expected to see cold, dead places, but right away they were blown away by their striking surfaces,” said Christine McCarthy, of Columbia University who carried out research into Europa’s ices while a graduate student at Brown University. “There was clearly some sort of tectonic activity — things moving around and cracking. There were also places on Europa that look like melt-through or mushy ice.”

It is now known that Europa possesses an extensive sub-surface ocean of water, protected by a fragmented, icy crust that appears to move much like the continental plates on Earth. Tidal pressures created during Europa’s orbit around Jupiter create an internal dynamo, which gently heats the moon from the core, maintaining the ocean in a liquid state. In addition, the motion of the icy plates are thought to generate their own heat through frictional processes at the boundaries. Much like the heat produced when repeatedly bending a wire coat hanger, heat is dissipated through the repeated tidal flexing of Europa’s crust at these boundaries.

But the small-scale processes behind this tidal dissipation are poorly understood and may have been woefully underestimated.

“People have been using simple mechanical models to describe the ice,” said McCarthy, “they weren’t getting the kinds of heat fluxes that would create these tectonics. So we ran some experiments to try to understand this process better.”

To simulate what might be going on in Europa’s crust, McCarthy headed a project to simulate the tidal pressures that would be felt by Europa’s ice in the lab. Loading ice samples into a compression apparatus at Brown University, the amount of deformation and heating could be measured.

Until now, it has been assumed that the majority of heating comes from friction between individual ice grains, so that would suggest the frictional heating is directly related to the size of the grains. But on varying the ice grain size in her samples, McCarthy noticed no difference in heat flux. Instead, she realized that the bulk of the heating comes from microscopic defects in the ice’s crystalline structure as the ice was deformed. The greater the deformation, the more heat is generated.

“Christine discovered that, relative to the models the community has been using, ice appears to be an order of magnitude more dissipative than people had thought,” said collaborator Reid Cooper of Brown University. “The beauty of this is that once we get the physics right, it becomes wonderfully extrapolative.

“Those physics are first order in understanding the thickness of Europa’s shell. In turn, the thickness of the shell relative to the bulk chemistry of the moon is important in understanding the chemistry of that ocean. And if you’re looking for life, then the chemistry of the ocean is a big deal.”

In short, the realization that the microscopic structure of the ice is generating the heat and that heat generated is way more than can be produced by frictional heating alone, scientists can learn a lot more about the physics of Europa’s icy crust and therefore open a new window into the chemistry of the liquid water ocean below.

Read more at Discovery News

35 Living Relatives Of Leonardo Da Vinci Identified

Leonardo Da Vinci has has 35 living relatives in Tuscany, two Italian researchers announced on Thursday.

Historian Agnese Sabato and art historian Alessandro Vezzosi, director of the Museo Ideale in the Tuscan town of Vinci, said they tracked down, one by one, the direct living descendants from Leonardo’s father, a Florentine legal notary named Ser Piero Da Vinci.

“Leonardo’s descendants are all living around Florence and nearby villages such as Empoli and Vinci,” Vezzosi told Discovery News.

It was believed that no traces were left of the painter, engineer, mathematician, philosopher and naturalist. The remains of Leonardo, who died in 1519 in Amboise, France, are believed to have been dispersed in the 16th century during religious wars.

With no Da Vinci’s remains to work on, Sabato and Vezzosi’ starting point was the documents left by Da Vinci’s grandfather, Antonio.

Antonio recorded on a notarial book Leonardo’s birth, indicating his son Ser Piero as Leonardo’s father. There was no mention of the mother’s name.

She is however recorded in one of Antonio’s notes dated 1457, and referred as Caterina, the wife of Achattabriga di Piero del Vaccha da Vinci.

Leonardo’s illegitimate status made even more difficult to reconstruct his family tree.

“We checked documents and tombs as far as France and Spain in order to reconstruct the history of Leonardo’s family,” Vezzosi said.

“We even found a unknown tomb of Leonardo’s family in Vinci,” he added.

Among the Renaissance genius’s relatives are an architect, a policeman, a pastry chef, an accountant and a retired blacksmith.

“I heard this story about our Da Vinci’s blood from my mother, but our family believed it was a legend,” Giovanni Calosi, one of the descendants, said.

Da Vinci’s relatives also include Italian director and producer of operas Franco Zeffirelli, famous for his 1968 version of Romeo and Juliet.

Zeffirelli, whose real name is Gianfranco Corsi, comes from one of the most famous families in Vinci.

“The Corsis related with the Da Vincis in 1794 thanks to the marriage between Michelangelo di Tommaso Corsi and Teresa Alessandra Giovanna di Ser Antonio Giuseppe Da Vinci, direct descendant of Leonardo’s father Ser Piero,” Vezzosi said.

As much as it sounds fascinating, the research presents some weak points. Indeed, the results from archival research could be patchy if one, if not more, false paternities -- where the biological father is not the recorded father -- have occurred somewhere along the 500-year-old male line.

“Regardless of the archival material, there is a strong probability of the male line especially being broken over such a large number of generations. Leonardo was himself illegitimate after all,” historian Kevin Schürer, Pro-Vice-Chancellor for Research at the University of Leicester, told Discovery News.

Schürer found non-paternity, or breaks, when he worked on the genealogy of King Richard III. In that case, genetic research proved that it wasn’t possible to trace a living relative on the male line through the Y chromosome, which is passed on from father to son.

In other words, a king may have been cuckolded, his wife giving birth to another man’s child.

“If they have been able to reliably trace male-line relatives with solid genealogical evidence then Y chromosome analysis would definitely be the way to go with the caveat that there could have been a false paternity, or paternities, along the way,” Turi King, a geneticist at the University of Leicester who carried out the DNA analysis on King Richard III, told Discovery News.

“If I was going to do the DNA for this, I’d want to test a number of distantly related men from the tree and see if their Y chromosomes match such that we’d expect,” King said.

“If they do, the higher up the tree they all connect (have a common ancestor) the better. In this way you can feel a bit safer, but not completely, that this is Da Vinci’s Y chromosome type,” she added.

Read more at Discovery News

Giant Rock Sphere Linked to Mysterious Civilization?

Bosnia’s “Indiana Jones” of archaeology claims to have found a massive, mysterious sphere embedded in the ground in a forest in Bosnia.

The controversial archaeologist, Semir Osmanagich, wrote in a blog that the sphere dates back more than 1,500 years and is “the most massive stone ball in Europe.” He estimates the sphere weighs some 30 tons or more.

Osmanagich said he discovered the sphere in the village of Podubravlje, near Zavidovici, Bosnia and Herzegovina, and his estimates show it has a radius of between 1.2 to 1.5 meters (about 3 feet, 11 inches to about 4 feet, 11 inches).

He says the sphere, in addition to his earlier claims that Bosnia is home to hidden ancient pyramids linked by underground tunnels, prove the existence of an advanced, lost civilization.

“It would be another proof that Southern Europe, Balkan and Bosnia, in particular, were home for advanced civilizations from distant past and we have no written records about them,” Osmanagich wrote in the blog post announcing the discovery for his non-profit group named The Archaeological Park: Bosnian Pyramid of the Sun Foundation.

Other archaeologists have dismissed Osmanagich’s previous claims about pyramid finds. Anthony Harding, President of the European Association of Archaeologists, described the claims as “complete fantasy.”

According to the International Business Times, some archaeologists have already dismissed Osmanagich’s sphere discovery saying that the rock was likely created naturally. Mandy Edwards of the University of Manchester's School of Earth, Atmospheric and Environmental Sciences told the Daily Mail that the rock was likely formed by the "precipitation of natural mineral cement within the spaces between sediment grains."

Could Osmanagich's new discovery be manmade?

Stone balls have been discovered around the world and linked to ancient civilizations. There are ancient volcanic stone spheres in western Mexico, stone balls in the small island in Pacific – Isla del Cano, volcanic stone balls on Easter Island, and others in Tunisia, and the Canary Islands.

Among the most famous of these finds are the more than 300 granite balls uncovered in Costa Rica. Each weighs up to 14 tons and were linked to the now extinct Diquis culture. In June 2014, the Stone Spheres of the Diquis was added to the UNESCO list of World Heritage Sites.

Osmanagich stands by his theory that his recent find could represent the biggest, manmade stone ball of them all. He added that his team has located stone balls in several other locations in Bosnia.

“We found granite stone balls in the Teocak village in northeastern Bosnia, volcanic stone ball near town of Konjic in middle Bosnia and sandstone stone spheres in many locations in western and middle Bosnia,” Osmanagich wrote.

Read more at Discovery News

Dark Matter Dwarf Galaxy Found Hidden in Spacetime Warp

There are few things that get us more excited than the mysteries of dark matter and the warping of spacetime, but when you have both wrapped into a stunning image of an Einstein ring, you know you’re onto something special.

In 2014, the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile observed a striking cosmic quirk during its Long Baseline Campaign. It saw a distant galaxy, warped beyond recognition, by the gravitational field of a massive galaxy in the foreground. This “Einstein ring” is so-called after Einstein’s theory of general relativity, which predicts spacetime can become bent by the presence of a powerful gravitational field.

In this case, the foreground galaxy had drifted in front of the more distant galaxy located some 12 billion light-years away, causing the distant galaxy’s light to be redirected around the warped spacetime. The result was a near-perfect circle of galactic light received by ALMA as one of the more extreme examples of gravitational lensing. Gravitational lensing is common in observations of the deep cosmos, where massive galaxies and galactic clusters bend spacetime like a malleable rubber sheet, often creating a “funhouse” mirror-like effect, distorting the observed shapes of distant galaxies whose light has taken a helter-skelter path through the confused spacetime landscape.

But sometimes, as this example proved, the alignment can be so perfect that the distant galaxy’s light can be warped around the symmetrical foreground galaxy, creating a ring that resembles a candle flame passing behind a magnifying glass. Gravitational lenses are the universe’s natural magnifying lenses and they are being used by the Hubble Space Telescope, for example, to superboost its observational power as part of the Frontier Fields project.

Though it looks like a pristine ring, this particular observation of the “SDP.81″ gravitational lens holds some tiny distortions in the shape of its ring and astronomers have used these distortions to reveal the presence of an invisible dwarf galaxy situated right next to the more massive lensing galaxy. And this tiny cluster of stars is packed with dark matter.

“We can find these invisible objects in the same way that you can see rain droplets on a window,” said Yashar Hezaveh at Stanford University, Calif., in a statement. “You know they are there because they distort the image of the background objects.” Raindrops will subtly refract light, distorting the light passing through a window; in much the same way, the invisible dwarf galaxy’s gravitational field is creating a minute distortion in the Einstein ring, revealing its presence in a tiny spacetime warp.

Finding this distortion and realizing it was due to the presence of an unseen galaxy was no easy task and required a huge computational effort, requiring, in part, time on one of the world’s most powerful supercomputers, the National Science Foundation’s Blue Waters.

Because of its close proximity to the larger galaxy, its estimated mass and lack of optical data, Hezaveh’s team thinks they’ve found a very dim dwarf galaxy that is dominated by dark matter.

Read more at Discovery News