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Wed, 22 Feb 2017
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A curious pair of galaxies

© European Space Agency
This color composite image of Arp 261 was created from images obtained using the FORS2 instrument on the ESO Very Large Telescope (VLT), at the Paranal Observatory in Chile. This image was created from images through blue, green, red and infrared filters and the total exposure time was 45 minutes.

Sometimes objects in the sky that appear strange, or different from normal, have a story to tell and prove scientifically very rewarding. This was the idea behind Halton Arp's catalogue of Peculiar Galaxies that appeared in the 1960s. One of the oddballs listed there is Arp 261, which has now been imaged in more detail than ever before using the FORS2 instrument on ESO's Very Large Telescope. The image proves to contain several surprises. Arp 261 lies about 70 million light-years distant in the constellation of Libra, the Scales. Its chaotic and very unusual structure is created by the interaction of two galaxies that are engaged in a slow motion, but highly disruptive close encounter. Although individual stars are very unlikely to collide in such an event, the huge clouds of gas and dust certainly do crash into each other at high speed, leading to the formation of bright new clusters of very hot stars that are clearly seen in the picture. The paths of the existing stars in the galaxies are also dramatically disrupted, creating the faint swirls extending to the upper left and lower right of the image. Both interacting galaxies were probably dwarfs not unlike the Magellanic Clouds orbiting our own galaxy.

The images used to create this picture were not actually taken to study the interacting galaxies at all, but to investigate the properties of the inconspicuous object just to the right of the brightest part of Arp 261 and close to the centre of the image. This is an unusual exploding star, called SN 1995N, that is thought to be the result of the final collapse of a massive star at the end of its life, a so-called core collapse supernova. SN 1995N is unusual because it has faded very slowly - and still shows clearly on this image more than seven years after the explosion took place! It is also one of the few supernovae to have been observed to emit X-rays. It is thought that these unusual characteristics are a result of the exploding star being in a dense region of space so that the material blasted out from the supernova plows into it and creates X-rays.


Discovery nears space station as debris nears, too

Seven astronauts raced to the international space station aboard space shuttle Discovery on Monday, while NASA debated whether the orbiting outpost will need to move aside to dodge part of an old Soviet satellite.

Space station astronauts had a close call last week with a small piece of orbiting junk, and NASA said Monday that debris from a satellite that broke apart in 1981 could come within about half a mile of the station early Tuesday.

NASA will decide later Monday whether to fire the space station's engines to nudge the complex out of the path of the debris.

Comment: Last month we were told that two satellites collided over Siberia. A few days later, fireballs were caught on video over Texas. Now in a week time we have heard twice of astronauts having to dodge 'space junk'.

Is there something we are not being told about what is going on in our atmosphere?


German researchers aim to recreate ancient Egyptian perfume

© Unknown
Researchers at Bonn University's Egyptian Museum aim to recreate a perfume used by Egypt's best-known female pharaoh, by analyzing residue from a well-preserved flacon, the museum said in a statement.

The 3,500-year-old filigree flacon bears the name of Hatshepsut, an 18th-dynasty pharaoh who ruled from around 1479 BC.

Michael Hoveler-Muller, the museum's curator, said: "The desiccated residues of a fluid can be clearly discerned in the x-ray photographs... Our pharmacologists are now going to analyze this sediment".

Magic Wand

Good as gold--What alchemists got right

Three hundred years ago, more or less, the last serious alchemists finally gave up on their attempts to create gold from other metals, dropping the curtain on one of the least successful endeavors in the history of human striving.

Centuries of work and scholarship had been plowed into alchemical pursuits, and for what? Countless ruined cauldrons, a long trail of empty mystical symbols, and precisely zero ounces of transmuted gold. As a legacy, alchemy ranks above even fantasy baseball as a great human icon of misspent mental energy.

But was it really such a waste? A new generation of scholars is taking a closer look at a discipline that captivated some of the greatest minds of the Renaissance. And in a field that modern thinkers had dismissed as a folly driven by superstition and greed, they now see something quite different.

Alchemists, they are finding, can take credit for a long roster of genuine chemical achievements, as well as the techniques that would prove essential to the birth of modern lab science. In alchemists' intricate notes and diagrams, they see the early attempt to codify and hand down experimental knowledge. In the practices of alchemical workshops, they find a masterly refinement of distillation, sublimation, and other techniques still important in modern laboratories.


Lasers provide antimatter bonanza

© J. McBride/LLNL
Hui Chen of the Lawrence Livermore National Laboratory adjusts equipment inside a vacuum chamber at Livermore's Jupiter laser facility. She and her colleagues used Jupiter's Titan laser to produce the highest density of antimatter ever created in a lab.
A research team used lasers to produce more positrons (anti-electrons) inside a solid than any previous experiment, according to the researchers involved. In the 13 March Physical Review Letters, the team describes firing short pulses from an intense laser onto thin gold targets and creating a high-density positron source that could be used to investigate exotic phenomena near black holes or supernovae.

Researchers currently produce positrons using one of two methods. At low energies, from a few to a few thousand electron-volts, they are obtained from radioactive isotopes, as in positron emission tomography (PET), a medical imaging technique. Alternatively, particle accelerators can produce positrons with energies of billions of electron-volts.

Hui Chen and Scott Wilks of the Lawrence Livermore National Laboratory in California and their colleagues now report that they have generated copious amounts of positrons with intermediate energies--in the range of a million electron-volts. They fired picosecond pulses with intensities of around 1020 watts per square centimeter from the Titan laser at Livermore's Jupiter laser facility onto millimeter-thick gold targets. Positrons were produced via the "Bethe-Heitler" process, in which part of each laser pulse creates a plasma on the surface of the target, and the remaining part of the pulse then blasts electrons from the plasma into the solid. Next, the electrons are slowed down by gold nuclei, an interaction that generates gamma-ray photons. The gamma rays then interact with more gold nuclei and transform into electron-positron pairs.


Army Robots: Will Humans Still Be in Control?

© Lockheed
The Squad Mission Support System (SMSS), which will likely head to Afghanistan for testing sometime next year, can be driven with a driver, tele-operated or remote controlled from a distance.
Is the day approaching when the U.S. military can deploy a robot that can drive itself around a corner, use sensors to detect an enemy fighter on-the-move and destroy the target instantly with missiles and machine guns - all without human intervention? The Pentagon thinks the day may be imminent and it wants to make ensure that its technology doesn't get ahead of military doctrine. It wants to be certain that there is always a "human" making decisions regarding the use of lethal force.

With some estimates of armed robots, with so-called Autonomous Navigation Systems, less than five years away, the U.S. Army is drafting a "White Paper," to establish a set of guidelines and principles for their use. "This is a concept paper to think about warfighting outcomes and what robotics will do for soldiers," says U.S. Army Lt. Gen. Michael Vane, who directs the Army Capabilities Integration Center, Fort Monroe, Va. "I am starting out with the idea of having an technology-enabled human. [But] we might someday come up with [separate] IT doctrine and robot doctrine." He reiterates that "we want to make the people or humans in charge under command and control in a 'whole of government' approach." The White Paper will be finished in the coming weeks, Army officials said. (See the most memorable movie robots.)


Batteries now included

© Corbis
The missing piece of the electric-car jigsaw has just turned up
If you want to buy an electric car, you can. Tesla Motors, a firm based in San Carlos, California, will sell you a nifty open-top sports job for $109,000. Not cheap, admittedly, but cheap to run. Plugged in overnight, it can be refuelled for the equivalent of 25 cents a litre of petrol. The catch is, "plugged in overnight". Tesla's vehicles use standard lithium-ion battery cells. As any owner of a mobile phone or laptop computer knows, these take time to charge. If you use 6,831 of them, as a Tesla sports car does, that time does tend to drag on. Which is fine if you are not planning a long trip the following day, for a full charge will take you about 350km (220 miles). But it might cramp the style of anyone planning to bomb down from, say, Paris to Cannes, and who would therefore need to refuel on the way.

Gerbrand Ceder and Byoungwoo Kang of the Massachusetts Institute of Technology hope to change this, and thus help make the electric car a work-a-day consumer item, rather than a high-end boy's toy. In this week's Nature they have published the technical details of a new battery material that will, if all goes well, take the waiting out of wanting, at least when it comes to recharging.

Broadly speaking, there are two ways of storing electrical energy in a chemical system. One is a standard battery, in which the whole material of the electrodes acts as a storage medium. That allows lots of energy to be squirrelled away, but makes it relatively hard to get at - and so it can be released or put back in only slowly. The other way is called a supercapacitor. This stores energy only at the surface of the electrode. It is quick to charge and discharge, but cannot hold much energy. The great prize in the battery world has thus been a material that can both store a lot and discharge rapidly, and it is this that Dr Ceder and Mr Kang think they have come up with.


Creationist students visit evolution headquarters: The Smithsonian

© Ricky Carioti/The Washington Post
Paleontologist Marcus Ross speaks under a towering tyrannosaurus rex at the National Museum of Natural History in Washington to students from Liberty University’s Advanced Creation Studies class. Each year the class travels from Lynchburg, Va., to visit the museum which, like all mainstream natural history institutions, is fundamentally Darwinian.
Washington - Every winter, David DeWitt takes his biology class to the Smithsonian's National Museum of Natural History, but for a purpose far different from that of other professors.

DeWitt brings his Advanced Creation Studies class up from Liberty University in Lynchburg, Va., hoping to strengthen his students' belief in a biblical view of natural history, even in the lion's den of evolution.

His yearly visit is part of a wider movement by creationists to confront Darwinism in some of its most redoubtable secular strongholds. As scientists celebrate the 200th anniversary of Charles Darwin's birth, his doubters are taking themselves on Genesis-based tours of natural history museums, aquariums, geologic sites and even dinosaur parks.


What happened to Pharaoh's workers?

© Al-Ahram Weekly
Clockwise fom top: Sennedjem and his wife harvesting in the afterlife; the burial chamber of Sennedjem's tomb; view of the workmen's village at Deir Al-Medina
We are gradually beginning to understand what happened to the elite body of artisans that worked on the royal tombs in the Valley of the Kings after they ceased to be built, says Jill Kamil

It appears that the workers, or should we say workmen and artisans, the people who built the rock-cut tombs of the Pharaohs in the Valley of the Kings from about 1500 BC onwards, may have later been employed on a project aimed at "emptying" and "recycling" their contents -- or that, at least, is what Rob Demaree of Leiden University thinks.


Patents Being Abused To Put Your Life In Danger

For years we've been writing about various abuses of the patent system, and how they damage innovation. There are times when we hear about abuses of the patent system that actually put lives in danger -- often around the pharmaceutical industry. At least in that case, you can sometimes understand the basic reasoning (even if it's actually incorrect). However, we recently came across an example of the patent system being abused in such an egregious manner that it's putting many lives at stake.