Welcome to Sott.net
Wed, 27 Oct 2021
The World for People who Think

Science & Technology
Map

Sherlock

The Search for an Ancient Supernova in the Antarctica

Image
© Keith Vanderlinde/NSF/Antarctic Sun
Ice cores from the Earth's polar regions may contain chemical traces of ancient supernovae.

Japanese scientists have journeyed to Antarctica to recover evidence of alterations to Earth's atmosphere, caused in medieval times by supernovae recorded by ancient scholars - including obscure Irish monasteries where monks later interpreted them signs of the Antichrist. No, this isn't the plot of the next Dan Brown novel (or a Dan Brown fan-fiction written by an X-Files addict): this is real science.

Supernovae release terrific amounts of energy, as in "If one happened too close the planet would be sterilized" truly terror-inducing terrific. Some of this energy is fired off as gamma rays, which can travel thousands of light-years and still pack enough of a punch after to alter the atmosphere - which is exactly what happened in 1006 and again in 1054, when gamma rays blasted the upper atmosphere and created spikes in NO3 levels. There was also quite a lot of visible light, creating a star visible even during the day which was noted by various Chinese, Egyptian and even monastic records.

To access past records of the atmosphere, a team of Japanese scientists carefully extracted 122 meters of ice core from Antarctica. Even better, to locate events on such a stretch of frozen time you use known volcanic atmosphere-altering events as reference points - in other words, these guys use exploding mountains as a ruler.

Einstein

Philosophy's Great Experiment

Philosophers used to combine conceptual reflections with practical experiment. The trendiest new branch of the discipline, known as x-phi, wants to return to those days. Some philosophers don't like it.

Warburton
© Unknown
Katja Wiech is a cheerful young German researcher who is fascinated by pain. She's discovered many things - for example, when devout Catholics are given electric shocks while looking at a picture of the Virgin Mary they feel less pain than atheists do when administered the same unpleasant treatment.

She works in a set of rooms at the end of a maze of corridors in the John Radcliffe Hospital in Oxford. In one room sits a magnetic resonance imaging (MRI) scanner. The magnet of this machine is so powerful it can seize a mobile phone from your hand,sending it flying through the air.

Her subjects lie flat on the scanner's bed, their head inside its white tube. A computer by their feet provides various stimuli - images, questions and so on - and is operated from an adjacent room divided off by a glass screen. The noise is very loud. There's a panic button if her subjects freak out.

Satellite

Geriatric Pulsar Still Kicking

The oldest isolated pulsar ever detected in X-rays has been found with NASA's Chandra X-ray Observatory. This very old and exotic object turns out to be surprisingly active.

The pulsar, PSR J0108-1431 (J0108 for short) is about 200 million years old. Among isolated pulsars -- ones that have not been spun-up in a binary system -- it is over 10 times older than the previous record holder with an X-ray detection. At a distance of 770 light years, it is one of the nearest pulsars known.

Pulsars are born when stars that are much more massive than the Sun collapse in supernova explosions, leaving behind a small, incredibly weighty core, known as a neutron star. At birth, these neutron stars, which contain the densest material known in the Universe, are spinning rapidly, up to a hundred revolutions per second. As the rotating beams of their radiation are seen as pulses by distant observers, similar to a lighthouse beam, astronomers call them "pulsars".

Eye 1

'Dark Cells' of Living Retina Imaged for the First Time

RPE cells
© David Williams, University of Rochester
This is a diagram of an RPE cell showing how they interact with the photoreceptors of the eye, and how their health differs in the eyes of a 3-year old and an 80-year old.
A layer of "dark cells" in the retina that is responsible for maintaining the health of the light-sensing cells in our eyes has been imaged in a living retina for the first time. The ability to see this nearly invisible layer could help doctors identify the onset of many diseases of the eye long before a patient notices symptoms. The findings are reported today's issue of Investigative Ophthalmology and Visual Science.

"Our goal is to figure out why macular degeneration, one of the most prevalent eye diseases, actually happens," says David Williams, director of the Center for Visual Science and professor in the Institute of Optics at the University of Rochester. "Macular degeneration affects one in 10 people over the age of 65, and as the average age of the U.S. population continues to increase, it is only going to get more and more common. We know these dark retinal cells are compromised by macular degeneration, and now that we can image them in the living eye, we might be able to detect the disease at a much earlier stage."

In 1997, Williams' team was the first to image individual photoreceptor cells in the living eye, using a technique called adaptive optics, which was borrowed from astronomers trying to get clearer images of stars. To image the dark cells behind the photoreceptors, however, Williams employed adaptive optics with a new method to make the dark cells glow brightly enough to be detected.

Magnify

Wars Are Increasingly Fought Like Video Games - Sometimes Even By Teenagers. But At What Cost?

A British Reaper drone taxis across a runway in southern Afghanistan. The unmanned aerial vehicle (UAV) is about the size of a light aircraft. Circling thousands of feet above the ground for hours at a time, armed with deadly hellfire missiles, it feeds live pictures to the soldiers below. But while those on the ground might have just started the evening shift in Kandahar, the drone's two-man pilot team will be watching dawn rise 7,000 miles to the west, in an air-conditioned room on Creech Air Force base in the middle of the Nevada desert.

Britain bought its first Reaper drones under an "urgent operational requirement" in October 2007, shipping the machines to Afghanistan, while dispatching a 50-strong RAF contingent of pilots and support staff to the US. But Britain's small UAV fleet is dwarfed by America's. The US now spends $0.5bn annually on drone development, and its fleet has grown from 300 to nearly 7,000 since 2002. In the last year the US military doubled the number of combat hour flown by its drone army.

In his book, Wired for War: The Robotics Revolution and Conflict in the 21st Century, Peter Singer of the Brookings Institution argues that this new generation of warrior - both human and machine - raises troubling legal and ethical questions about the nature of wars. But it is the human dimension that is most challenging.

Telescope

Hot Solar Winds: Energy Simulation Explains Physical Mystery of the Voyager

With a new 3D-model for energy simulation scientists from Bochum and Huntsville, USA, are studying the 'physical mystery' of the Voyager. Over 30 years ago the spacecraft detected particles in solar wind which were 'hotter' than they should have been according to the existing theory expounded by the mathematician Andrey Kolmogorov in 1941.

The Bochum plasma physicists Prof. Padma Kant Shukla and Dr. Dastgeer Shaikh from the University of Alabama are thereby the first to verify by means of computer simulation that the non-linear characteristics of turbulences in the plasma carried by the solar wind differs from the familiar model for dynamic fluids. The scientists have published their results in Physical Review Letters.

Sherlock

Submerged Ancient City to See Daylight in Bulgaria

Discovered under centuries-old layers of dirt in 1948, then submerged under 20 metres of water, the ancient city of Seuthopolis is to emerge once again in a bold rescue project in Bulgaria.

The magnificently preserved city, founded by the Thracian king Seuthes III in 323 BC, was discovered in central Bulgaria during the construction of a dam on the Tundzha river.

Despite the stunning discovery, Communist authorities went ahead with the dam and created the Koprinka reservoir six years later, in 1954, flooding Seuthopolis under 150 million cubic metres of water.

Now, a 150-million-euro ($192-million) project by Bulgarian architect Jeko Tilev aims to right the wrong and expose the polis at the bottom of the reservoir to archaeologists and tourist by creating a dry well 20 metres deep and 420 metres across.

Sherlock

Tools Unearth 13,000 Years of History

It turns out that the first people to get in on Boulder real estate were the Clovis - a nomadic people who lived 13,000 years ago.

We know this from a cache of Clovis tools buried beneath the lawn of biotech entrepreneur Patrick Mahaffy.

The 83 stone implements - including bi facial knives and a tool resembling a double-bitted ax - were unearthed in May by a landscaping crew.

It is one of only two known Clovis caches. The other is in Washington state.

"There is a magic to these artifacts," said Mahaffy, who backed a $7,000 analysis of the knife and ax blades.

Mahaffy said landscapers were digging out a space to build a fish pond when their shovels struck stone, unearthing the space where the tools had been buried. Reporting of the find was delayed until the analysis was complete, officials involved in the venture said.

Grey Alien

Galaxy may be full of 'Earths,' alien life

Sun
© Agency France-Presse/ Getty Images
An artist's impression shows a planet passing in front of its parent star. Such events are called transits.
As NASA prepares to hunt for Earth-like planets in our corner of the Milky Way galaxy, there's new buzz that "Star Trek's" vision of a universe full of life may not be that far-fetched.

Pointy-eared aliens traveling at light speed are staying firmly in science fiction, but scientists are offering fresh insights into the possible existence of inhabited worlds and intelligent civilizations in space.

There may be 100 billion Earth-like planets in the Milky Way, or one for every sun-type star in the galaxy, said Alan Boss, an astronomer with the Carnegie Institution and author of the new book The Crowded Universe: The Search for Living Planets.

He made the prediction based on the number of "super-Earths" -- planets several times the mass of the Earth, but smaller than gas giants like Jupiter -- discovered so far circling stars outside the solar system.

Magnify

13,000 Clovis-era tool cache unearthed in Colorado shows evidence of camel, horse butchering

Image
© Photo by Glenn Asakawa, University of Colorado
Three stone artifacts from a 13,000-thousand-year-old Clovis-era cache unearthed recently in the city limits of Boulder, Colo. are shown by University of Colorado at Boulder anthropology Professor Douglas Bamforth and Boulder resident Patrick Mahaffy, who owns the property where the cache was found. Two of the more than 80 implements in the cache were shown to have protein residue from now-extinct North American camels and horses.
A biochemical analysis of a rare Clovis-era stone tool cache recently unearthed in the city limits of Boulder, Colo., indicates some of the implements were used to butcher ice-age camels and horses that roamed North America until their extinction about 13,000 years ago, according to a University of Colorado at Boulder study.

The study is the first to identify protein residue from extinct camels on North American stone tools and only the second to identify horse protein residue on a Clovis-age tool, said CU-Boulder Anthropology Professor Douglas Bamforth, who led the study. The cache is one of only a handful of Clovis-age artifact caches that have been unearthed in North America, said Bamforth, who studies Paleoindian culture and tools.