Science & TechnologyS


Wedding Rings

New microcrystalline form of gold is much golder than normal gold

Michael Marshall
New Scientist
Sat, 14 Jul 2018 16:44 UTC
gold nugget
© Susan E. Degginger / Alamy Stock PhotoNot gold enough?
New form of gold is much golder than normal gold

All that glitters is not gold - but sometimes it really, really is. Researchers have made a new kind of gold crystal that is even more gold-like than regular gold.

Gold is a precious metal, which means that as well as being attractively shiny it is almost entirely chemically inert. Unlike other metals, it does not rust when exposed to air, and retains its lustre indefinitely.

It's said this property is why wedding rings are traditionally made of gold: it represents an eternity of love. Silver is another such "noble metal", but even silver reacts slowly with oxygen in the air, so requires occasional polishing.

In 2015 Giridhar Kulkarni of the Centre for Nano and Soft Matter Sciences in Bangalore, India and his colleagues described a new form of gold: microcrystals measuring between 2 and 17 micrometres. They made them by heating gold chloride to 220 °C for 30 minutes in the presence of a second chemical called tetraoctylammonium bromide. They look like angular, knobbly sausages.
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Mars

Crust-formation on Mars means red planet could have been habitable 100 million years before Earth was

Leah Crane
New Scientist
Sat, 14 Jul 2018 15:45 UTC
mars rocks
© NASA
The solid surface of Mars formed 100 million years before Earth's - meaning life would have had a head start to evolve on the Red Planet.

Early Mars, like the other rocky planets, was covered in a global magma ocean. The top of that sea of molten rock eventually hardened to a crust, but we weren't sure exactly when - researchers thought it could have happened between 30 million and 100 million years after the start of the solar system. Now, we have evidence that it was much faster.

Laura Bouvier at the University of Copenhagen in Denmark and her colleagues figured this out by studying ancient crystals in a Martian meteorite found in Morocco in 2011, dating them to about 4.4 billion years old.

Based on the compositions of the crystals, the researchers suggest that Mars first formed a crust about 4.5 billion years ago. This initial surface survived for about 100 million years before parts of it were melted again, possibly by impacts, to create the magma that the zircons came from.

Comment: See also: Discovery of organic molecule on Mars strongly suggests life exists on other planets

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Colosseum

Genetic research suggests the Roman Empire helped to spread tuberculosis across three continents

Clare Wilson
New Scientist
Tue, 03 Jul 2018 00:00 UTC
romans spread tuberculosis
© Marco Ravagli / Barcroft MediaWhat did the Roman Empire ever do for us? It spread tuberculosis
The Romans gave us roads, public toilets and the modern calendar, but we may also have them to thank for spreading a deadly disease: tuberculosis.

A genetic analysis suggests that while TB first arose about 5000 years ago in Africa, the Roman Empire was behind its more recent, rapid spread around Europe and beyond.

TB is a lung infection that, if left untreated, can cause a chronic cough, weight loss and a lingering death. By some estimates the bacterium that causes it, Mycobacterium tuberculosis, has killed more people than any other infectious disease in history.

The strain of TB that affects humans can't be carried by other animals, says Caitlin Pepperell at the University of Wisconsin-Madison. "So the evolution of the bacterium is inextricably tied to humans."

To find out its origins, Pepperell's team looked at the genetic sequences of 552 samples of TB bacteria obtained from people across most of the world. They left out North and South America as people in these continents are mainly affected by TB bacteria that arrived with the first Europeans.

Comment: Other research suggests that the spread of farming enabled the disease to initially take hold in human populations: Tuberculosis genomes and human history

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Mars

Solar System-wide Climate Change: Green flashes seen on Mars amidst 'global' dust storm


Space Weather
Thu, 12 Jul 2018 20:33 UTC
Green blue flash on Mars
Mars is approaching Earth for a 15-year close encounter on July 27th. The Red Planet now outshines every object in the sky except the sun, Moon, and Venus. Mars is doing things only very luminous objects can do--like produce a green flash. Watch this video taken by Peter Rosén of Stockholm, Sweden, on July 12th:


"Mars was shining brightly in the early morning sky," he says. "At an altitude of only 6.5° above the horizon, the turbulence was extreme, sometimes splitting the planet's disc in 2 or 3 slices and displaying a green and blue flash resembling those usually seen on the sun."

That's not all. Mars is also making its own glitter paths. Last night, Alan Dyer photographed this specimen from Driftwood Beach at Waterton Lakes National Park, Alberta:
Fireball over Alberta
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Jet5

PAK DA, Russia's strategic subsonic, will use stealth tech


RT
Fri, 13 Jul 2018 17:54 UTC
Jet bomber thing
© Sergey Mamontov/SputnikAn NK-32-02 engine in the Tu-160M strategic bomber. PAK FA may use a similar one.
PAK DA, Russia's future subsonic nuclear-capable bomber, will have stealth technology incorporated in its planer, a defense official confirmed after touring a plant, where the advanced project is being implemented.

The Russian long-range aircraft is expected to undergo a major overhaul over the next two decades. The time-tested Tu-95 bombers would be phased out in favor or a yet-to-be named subsonic comber dubbed PAK FA. Russia will also resume the production of supersonic Tu-160Ms while working on the advanced "M2" version of the aircraft. In the meantime its existing fleet of Tu-22M3s and Tu-160 would be upgraded to the latest variants of the aircraft.
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Galaxy

Neutrino that struck Antarctica traced to galaxy 3.7 billion light years away

Ian Sample
Guardian
Thu, 12 Jul 2018 16:40 UTC
South Pole Station in Antarctica
© Felipe Pedreros/IceCube/NSFThe IceCube laboratory at the Amundsen-Scott South Pole Station in Antarctica.
Neutrino that struck Antarctica traced to galaxy 3.7bn light years away

Discovery may solve 100-year-old puzzle of high-energy cosmic rays that occasionally hit Earth

A mysterious, ghostly particle that slammed into Earth and lit up sensors buried deep beneath the south pole has been traced back to a distant galaxy that harbours an enormous spinning black hole.

Astronomers detected the high-energy neutrino, a kind of subatomic particle, when it tore into the southern Indian Ocean near the coast of Antarctica and carried on until it struck an atomic nucleus in the Antarctic ice, sending more particles flying.

The event, which took place on 22 September 2017, was captured by the IceCube experiment, a cubic kilometre of clear ice kitted out with sensors to detect such intergalactic incidents. Within a second of the particle being spotted, IceCube issued an automatic alert, prompting an international race to find the neutrino's origin.

Comment: Earth's weakening magnetic field is allowing more cosmic rays to enter and this has been demonstrated to contribute to increased cloud cover, and one wonders how else these high energy particles may affect life on our planet:

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Arrow Up

Ötzi enjoyed a very high-fat diet

Jeff Glorfeld
Cosmos Magazine
Thu, 12 Jul 2018 21:04 UTC
Ötzi, the Iceman
© Andrea Solero/AFP/Getty ImagesÖtzi, the Iceman, tattooed and full of goat fat.
Imagine you're out for an evening of pizza and beer and on the way home you're flash-frozen into a block of ice, only to have hordes of scientists thaw you out a few thousand years later and systematically delve into every conceivable aspect of your long-lost life.

Such has been the fate Ötzi, also known as the Iceman, whose frozen body was discovered in 1991 by a pair of German tourists hiking in the southern Tyrol on the border between Austria and Italy. Ötzi's corpse was found at an elevation of 3210 metres above sea level, where it had rested undisturbed for more than 5300 years.

In the latest examination, researchers reporting in the journal Current Biology say their in-depth analysis of his stomach contents reveals much about his dietary habits. Among other things, they say, his last meal was heavy on fat.

When Ötzi was discovered, what was at first thought to be the corpse of some unfortunate modern-day climber was eventually revealed to be that of oldest naturally preserved ice mummy.

Since then, study of Ötzi, his clothing and the tools and weapons he carried have revealed much about life in the Copper Age, or Eneolithic Period.

Much has been written, for example, about his more than 50 tattoos.

Researchers led by Frank Maixner, of the Eurac Research Institute for Mummy Studies, in Bolzano, Italy, used highly detailed biological analysis to reconstruct the Iceman's last meal. They found that he had a "remarkably high proportion of fat in his diet".
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Microscope 1

Slime molds are able to remember - but do they really learn?

Katia Moskvitch
Quanta Magazine
Mon, 09 Jul 2018 16:35 UTC
slime mold
© Audrey Dussutour, CNRSDespite its single-celled simplicity and lack of a nervous system, the slime mold Physarum polycephalum may be capable of an elementary form of learning, according to some suggestive experimental results.
Evidence mounts that organisms without nervous systems can in some sense learn and solve problems, but researchers disagree about whether this is "primitive cognition."

Slime molds are among the world's strangest organisms. Long mistaken for fungi, they are now classed as a type of amoeba. As single-celled organisms, they have neither neurons nor brains. Yet for about a decade, scientists have debated whether slime molds have the capacity to learn about their environments and adjust their behavior accordingly.

For Audrey Dussutour, a biologist at France's National Center for Scientific Research and a team leader at the Research Center on Animal Cognition at Université Paul Sabatier in Toulouse, that debate is over. Her group not only taught slime molds to ignore noxious substances that they would normally avoid, but demonstrated that the organisms could remember this behavior after a year of physiologically disruptive enforced sleep. But do these results prove that slime molds - and perhaps a wide range of other organisms that lack brains - can exhibit a form of primitive cognition?

Comment: Other interesting instances of apparent learning:

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Gear

Researchers couple artificial atom to acoustic resonator to simulate light-based quantum systems


MIPT
Wed, 11 Jul 2018 13:47 UTC
Researchers from Russia and Britain have demonstrated an artificial quantum system, in which a quantum bit interacts with an acoustic resonator in the quantum regime. This allows the familiar effects of quantum optics to be studied on acoustic waves and enables an alternative approach to quantum computer design, which is based on acoustics and could make quantum computers more stable and compact. The paper reporting the results was published in Physical Review Letters.

Resonator 1
© Elena Khavina/MIPT Press office and the researchersFigure 1. Schematic of the chip. The resonator is a Fabry-Perot cavity formed by two Bragg gratings, each consisting of 200 parallel stripes (shown in yellow) separated by half the acoustic wavelength. The wavelength is equal to 0.98 micrometers, or 980 nanometers. There are two interdigital transducer (IDT) ports - a receiver and a transmitter - and a qubit (transmon) inside the resonator. SQUID is the part of the transmon sensitive to weak magnetic fields.
"We are the first to demonstrate an interaction between a qubit and a surface acoustic wave resonator in the quantum regime. Previously, resonators of this kind were studied, but without a qubit. Likewise, qubits with surface acoustic waves were studied, but those were running waves, without a resonator. The quantum regime was demonstrated on bulk resonators, but this didn't go far, perhaps due to difficulties in fabrication. We used a planar structure fabricated with existing technologies," says Aleksey Bolgar, researcher at MIPT's Artificial Quantum Systems Lab, where the study was conducted.
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Ice Cube

13,000 year old clues of deluge and abrupt ice age found in Arctic

Woods Hole Oceanographic Institution
Phys.org
Wed, 11 Jul 2018 13:52 UTC
eastern Beaufort Sea
© Lloyd Keigwin, Woods Hole Oceanographic InstitutionIn 2013, a team of researchers set sail to the eastern Beaufort Sea in search of evidence for the flood near where the Mackenzie River enters the Arctic Ocean, forming the border between Canada's Yukon and Northwest territories. From aboard the US Coast Guard Cutter Healy in ice-covered waters, the team gathered sediment cores from along the continental slope east of the Mackenzie River. Above, the piston corer is shown in horizontal position, with the gravity corer hanging vertically ready to be launched.
A research team led by Woods Hole Oceanographic Institution (WHOI) found the fingerprint of a massive flood of fresh water in the western Arctic, thought to be the cause of an ancient cold snap that began around 13,000 years ago.

"This abrupt climate change-known as the Younger Dryas - ended more than 1,000 years of warming," explains Lloyd Keigwin, an oceanographer at WHOI and lead author of the paper published online July 9, 2018, in the journal Nature Geoscience.

The cause of the cooling event, which is named after a flower (Dryas octopetala) that flourished in the cold conditions in Europe throughout the time, has remained a mystery and a source of debate for decades.

Comment: While this study confirms that there was a great flood in the region, the scientists assumption of melting glaciers isn't supported by their findings. This deluge of water, talked about in many myths all over the world, could have come about through the disruption of former lakes due to geological shifts or due to epic rainfall. What is interesting is that the ice age coincided with a disruption and weakening of oceanic circulation - which is exactly what we're seeing today:

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