Science & Technology

Scientists discover radio emissions from fireballs

Phys Org
Tue, 08 Jul 2014 16:39 UTC

© Phys Org
These images show the sky above the first LWA station. Each image shows the full sky, down to the horizon at the image's edge.

Streaking across the sky at more than 50 kilometers per second at atmospheric heights of more than a 90 kilometers high, researchers using the first station of University of New Mexico's Long Wavelength Array (LWA) saw something new that had never been seen before; something that could hold a treasure trove of new information in the world of physics.

The first station of the LWA, known as LWA1, is a unique telescope that consists of a collection of 256 dipoles combined into one massive array with a collective-area of a 100-meter dish. The LWA1, is a highly sensitive telescope that can create images of the entire sky. It allows researchers to keep eyes on the whole sky day and night, probing a relatively unexplored region of the electromagnetic spectrum.

Within six months of turning LWA1 on, UNM Department of Physics Professor Greg Taylor and his team got the all sky imaging up and running. Shortly thereafter, they started to search for transients, brief pulses of radio waves coming from the sky. Ken Obenberger, a UNM graduate student, and colleagues searched for transients in more than 11,000 hours of all-sky images from the LWA at frequencies between 25 and 75 MHz. In this data he identified 49 long (30 seconds or longer) transients.

The photon underproduction crisis: Missing photons or missing electricity?

phys.org
Tue, 08 Jul 2014 11:39 UTC

© Ben Oppenheimer and Juna Kollmeier
Computer simulations of intergalactic hydrogen in a "dimly lit" universe (left) and a "brightly lit" universe (right) that has five times more of the energetic photons that destroy neutral hydrogen atoms. Hubble Space Telescope observations of hydrogen absorption match the picture on the right, but using only the known astronomical sources of ultraviolet light produces the much thicker structures on the left, and a severe mismatch with the observations.

Something is amiss in the Universe. There appears to be an enormous deficit of ultraviolet light in the cosmic budget.

Comment: Not exactly. What the paper is about is that the actual models of intergalactic medium do not explain what is observed. Something is amiss with the models, the Universe is what it is.

The vast reaches of empty space between galaxies are bridged by tendrils of hydrogen and helium, which can be used as a precise "light meter." In a recent study published in The Astrophysical Journal Letters, a team of scientists finds that the light from known populations of galaxies and quasars is not nearly enough to explain observations of intergalactic hydrogen. The difference is a stunning 400 percent.

"It's as if you're in a big, brightly-lit room, but you look around and see only a few 40-watt lightbulbs," noted Carnegie's Juna Kollmeier, lead author of the study. "Where is all that light coming from? It's missing from our census."

Strangely, this mismatch only appears in the nearby, relatively well-studied cosmos. When telescopes focus on galaxies billions of light years away (and therefore are viewing the universe billions of years in its past), everything seems to add up. The fact that this accounting works in the early universe but falls apart locally has scientists puzzled.

Comment: In other words, the models work fine for the less well-studied cosmos.

Comment: A preprint of the published paper can be found here.

Deep in the Antarctic ice, the history of planet's biggest volcanic explosions

Steve Connor
The Independent, UK
Sun, 06 Jul 2014 12:04 UTC

Scientists have been able to trace the history of volcanic eruptions over the last 2,000 years by analysing deposits of sulphate dust in a series of ice cores drilled deep into the West Antarctic ice sheet

Some of the biggest volcanic eruptions of the last 2,000 years have left their indelible mark deep within the pristine ice sheet of the Antarctic, a study has found.

Scientists have been able to trace the most complete history of volcanic eruptions since the birth of Christ by analysing deposits of sulphate dust in a series of ice cores drilled deep into the West Antarctic ice sheet.

The time series from 26 separate ice cores drilled out from 19 different sites shows that there were 116 volcanic eruptions in the past two millennia that were big enough to result in plumes of volcanic sulphate dust being transported as far as the South Pole.

Most the eruptions cannot be identified, however the biggest, in 1257, was already hinted at from medieval chronicles and tree rings. Scientists identified the sulphate deposits as coming from the Samalas volcano on Lombok Island of Indonesia.

EU to battle US tech giants over digital 'colonization' and tax evasion

Juliette Garside
The Guardian
Sat, 05 Jul 2014 00:00 UTC

Within the salons of the Elysée Palace, along the corridors of the European parliament and under the glass dome of the Reichstag, Old Europe is preparing for a new war. This is not a battle over religion or politics, over land or natural resources. The raw material that Paris, Brussels and Berlin are mobilising to defend is the digital environment of Europe's inhabitants; their enemies are the Silicon Valley corporations that seek to dominate it.

Coal, gas and oil powered the industrial revolution, but in the digital era, data is replacing fossil fuels as the most valuable resource on Earth, and the ability to collect and interrogate it has created organisations with a power that can at times seem beyond the control of nation states. Amazon, Apple, Facebook and Google represent, in the words of Germany's economy minister Sigmar Gabriel, "brutal information capitalism", and Europe must act now to protect itself.

"Either we defend our freedom and change our policies, or we become digitally hypnotised subjects of a digital rulership," Gabriel warned in a passionate call to action published by the Frankfurter Allgemeine. "It is the future of democracy in the digital age, and nothing less, that is at stake here, and with it, the freedom, emancipation, participation and self-determination of 500 million people in Europe."

Discovery of Neandertal trait in ancient skull raises new questions about human evolution

Phys Org
Mon, 07 Jul 2014 14:01 UTC

© Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Science
The Xujiayao 15 late archaic human temporal bone from northern China, with the extracted temporal labyrinth, is superimposed on a view of the Xujiayao site.

Re-examination of a circa 100,000-year-old archaic early human skull found 35 years ago in Northern China has revealed the surprising presence of an inner-ear formation long thought to occur only in Neandertals.

"The discovery places into question a whole suite of scenarios of later Pleistocene human population dispersals and interconnections based on tracing isolated anatomical or genetic features in fragmentary fossils," said study co-author Erik Trinkaus, PhD, a physical anthropology professor at Washington University in St. Louis.

"It suggests, instead, that the later phases of human evolution were more of a labyrinth of biology and peoples than simple lines on maps would suggest."

The study, forthcoming in the Proceedings of the National Academy of Sciences, is based on recent micro-CT scans revealing the interior configuration of a temporal bone in a fossilized human skull found during 1970s excavations at the Xujiayao site in China's Nihewan Basin.

Trinkaus, the Mary Tileston Hemenway Professor in Arts & Sciences, is a leading authority on early human evolution and among the first to offer compelling evidence for interbreeding and gene transfer between Neandertals and modern human ancestors.

His co-authors on this study are Xiu-Jie Wu, Wu Liu and Song Xing of the Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, and Isabelle Crevecoeur of PACEA, Université de Bordeaux.

Rewriting the history of volcanic forcing during the past 2,000 years

Phys Org
Sun, 06 Jul 2014 21:39 UTC

© Joseph McConnell
An ice core section is simultaneously analyzed for a variety of elements and chemical species in DRI's ultra-trace ice core laboratory while slowly melting the ice on a heated melter plate.

A team of scientists led by Michael Sigl and Joe McConnell of Nevada's Desert Research Institute (DRI) has completed the most accurate and precise reconstruction to date of historic volcanic sulfate emissions in the Southern Hemisphere.

The new record, described in a manuscript published today in the online edition of Nature Climate Change, is derived from a large number of individual ice cores collected at various locations across Antarctica and is the first annually resolved record extending through the Common Era (the last 2,000 years of human history).

"This record provides the basis for a dramatic improvement in existing reconstructions of volcanic emissions during recent centuries and millennia," said the report's lead author Michael Sigl, a postdoctoral fellow and specialist in DRI's unique ultra-trace ice core analytical laboratory, located on the Institute's campus in Reno, Nevada.

These reconstructions are critical to accurate model simulations used to assess past natural and anthropogenic climate forcing. Such model simulations underpin environmental policy decisions including those aimed at regulating greenhouse gas and aerosol emissions to mitigate projected global warming.

Powerful volcanic eruptions are one of the most significant causes of climate variability in the past because of the large amounts of sulfur dioxide they emit, leading to formation of microscopic particles known as volcanic sulfate aerosols. These aerosols reflect more of the sun's radiation back to space, cooling the Earth. Past volcanic events are measured through sulfate deposition records found in ice cores and have been linked to short-term global and regional cooling.

Frankenfoods: Food produced in the laboratory might sound appealing but researchers are finding slim pickings

Andrew Masterson
The Sydney Morning Herald
Fri, 04 Jul 2014 07:24 UTC

© Ionat Zurr and Oron Catts
Engineered steak: The first attempt to use tissue engineering for meat production without the need to slaughter animals, part of Oron Catts' research at Harvard.

Much like hoverboards and personal jet-packs, the promise of cheap and abundant lab-grown food always seems to be just around the corner.

According to the narrative, we will enjoy a future in which supply is assured, greenhouse-gas-farting cows are greatly reduced in number, and supermarket shelves around the world groan beneath the weight of products born in petri dishes.

Right now, the vision of plenty is being driven by start-ups intending to use 3D-printing as the technology by which well-established in-vitro food-growing methods can be scaled up to industrial levels.

One such start-up is Modern Meadow, a US-based company aiming to 3D-print leather and meat. The business is funded by PayPal founder Peter Thiel. Its CEO, Andras Forgacs corr, aims to create ''the future of humanely sourced meat''.

In Britain a company called Dovetailed is trumpeting its ability to 3D-print edible fruit. ''We have re-invented the concept of fresh fruit on demand,'' creative director Vaiva Kalnikaite recently told a grocery trade publication.

But well-credentialled skeptics stand ready in the wings, happy to puncture the dream of a digitally made cornucopia.

''I think in-vitro meat is a fantastic way of introducing novelty foods for the rich,'' says Oron Catts, who heads a world-renowned bio-art laboratory called SymbioticA, based at the University of Western Australia.

''It's never going to be a way to feed the world - there's no way to upscale the process to that level,'' he says. ''The world will never be fed by factory-grown meat.''

Comment: Food is much more than just a mixture of nutrients - proteins, fats, carbohydrates, minerals and vitamins. Food is part of the living system and is produced by it to nourish and sustain its inhabitants in a finely balanced and tuned manner. The push for in-vitro meat is another plot by the big corporations to destroy our meat supply and our health.

After all, one movie comes to mind - Soylent Green ...

Thunderbolts Space News: NASA warns astronauts of electric asteroids - Has the U.S. space agency suddenly seen the light?

Thunderbolts Project
YouTube
Fri, 04 Jul 2014 14:30 UTC

A new NASA report describes the potential dangers that electrical environments of asteroids could pose for astronauts in future space missions. NASA scientists are now attempting to create models that will successfully predict dangerous electrical interactions between an approaching spacecraft and an asteroid. The report begins with a brief, surprising description of space rarely seen in official press releases.