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Tue, 16 Jan 2018
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Snowflake Cold

Researchers cool object beyond limits of known physics

supercooled membrane physics
© Teufel/NIST
Tiny supercooled membrane
For the first time, physicists have cooled a mechanical object to a temperature colder than previously thought possible, taking it below the so-called "quantum limit" and bending the laws of physics.

Using a new technique, the team managed to chill a microscopic mechanical drum to an unheard-of 360 microKelvin, or 10,000 times colder than the vacuum of space. It's the coldest mechanical object on record.

"It's much colder than any naturally occurring temperature anywhere in the Universe," team leader John Teufel from the US National Institute of Standards and Technology in Boulder, Colorado, told Leah Crane from New Scientist.

Bulb

Four-dimensional physics now studied in two dimensions

blue box red things
© Rechtsman laboratory, Penn State University
Illustration of light passing through a two-dimensional waveguide array. Each waveguide is essentially a tube, which behaves like a wire for light, inscribed through high-quality glass using a powerful laser, closely spaced to form the array. Light that flows through the device behaves precisely according to the predictions of the four-dimensional quantum Hall effect.
For the first time, physicists have built a two-dimensional experimental system that allows them to study the physical properties of materials that were theorized to exist only in four-dimensional space. An international team of researchers from Penn State, ETH Zurich in Switzerland, the University of Pittsburgh, and the Holon Institute of Technology in Israel have demonstrated that the behavior of particles of light can be made to match predictions about the four-dimensional version of the "quantum Hall effect" -- a phenomenon that has been at the root of three Nobel Prizes in physics -- in a two-dimensional array of "waveguides."

A paper describing the research appears January 4, 2018 in the journal Nature along with a paper from a separate group from Germany that shows that a similar mechanism can be used to make a gas of ultracold atoms exhibit four-dimensional quantum Hall physics as well.

"When it was theorized that the quantum Hall effect could be observed in four-dimensional space," said Mikael Rechtsman, assistant professor of physics and an author of the paper, "it was considered to be of purely theoretical interest because the real world consists of only three spatial dimensions; it was more or less a curiosity. But, we have now shown that four-dimensional quantum Hall physics can be emulated using photons -- particles of light -- flowing through an intricately structured piece of glass -- a waveguide array."

Fish

Russian scientists develop experimental underwater breathing technique - aimed at rescuing submarine crews

woman swimming underwater
© CCO
People and other air-breathing creatures normally drown when they get too much water in their lungs, but Russian scientists have proved that a dog can survive underwater using liquid breathing technology in an experiment aimed at saving the lives of submarine crews.

Liquid breathing is a form of respiration in which a normally air-breathing organism breathes an oxygen-rich liquid.

For many decades scientists have been looking for novel methods of salvaging distressed submariners and helping pilots and cosmonauts withstand extreme g-loads during long-term spaceflights.

During a scientific experiment, virtually identical to the system portrayed in James Cameron's 1989 science fiction movie The Abyss, a dachshund was dunked face down into a vessel filled with a liquid saturated with oxygen.

Just a couple of minutes later the dog was able to adapt to the new environment.

Laptop

Major chip flaw leaves billions of devices vulnerable to security concerns

intel cpu
Two major flaws in computer chips could leave a huge number of computers and smartphones vulnerable to security concerns, researchers revealed Wednesday.

And a U.S. government-backed body warned that the chips themselves need to be replaced to completely fix the problems.

The flaws could allow an attacker to read sensitive data stored in the memory, like passwords, or look at what tabs someone has open on their computer, researchers found. Daniel Gruss, a researcher from Graz University of Technology who helped identify the flaw, said it may be difficult to execute an attack, but billions of devices were impacted.


Called Meltdown and Spectre, the flaws exist in processors, a building block of computers that acts as the brain. Modern processors are designed to perform something called "speculative execution." That means they predict what tasks they will be asked to execute and rapidly access multiple areas of memory at the same time.

That data is supposed to be protected and isolated, but researchers discovered that in some cases, the information can be exposed while the processor queues it up.

Comment: Apparently this issue affects devices from the last 20 years. Wonder how long the folks at the NSA have known about this...


Nebula

Russia joins search for space signals of unknown origin

Spiral galaxy
© AP Photo/ Hubble Heritage
Sergei Trushkin, an astronomer from the Special Astrophysical Observatory of the Russian Academy of Sciences, has explained why scientists are eager to discover the mystery of the fast radio burst phenomenon and how Russia's RATAN-600 radio telescope could help them.

The first fast radio burst (FRB) was identified in 2007 in data recorded by the Parkes Observatory in Australia. An FRB is a high-energy astrophysical phenomenon of a radio pulse lasting only for a few milliseconds.

"Taking into account our modest capabilities, we expected to identify a maximum of three to five such pulses during a year of observation. On the other hand, even if we manage to discover at least one event on the frequencies which are used to study the phenomenon, our understanding of these signals will radically change," Trushkin said at the annual conference "High Energy Astrophysics" in Moscow.

Laptop

Hacking the Arpanet and the 'good ol' boys' of the NET

Internet

Photo by Julian Burgess | CC BY 2.0
It's hard to imagine now, but there was a time before the Internet, a time when computers took up more space than the acolytes who tended to their needs. In the 70s I was one such boffin, a postgrad hacking away in a university R&D lab. Computers then were still quite dear, and so we made do with terminals that sucked electrons from the teat of a minicomputer several blocks away through fiber cable.

Our digital host had recently been hooked up to the Arpanet, the Internet's predecessor, giving us real-time access to several dozen academic, government, and military computers scattered across the US. We used it to chat and exchange files and email with people we knew here and there, but mostly we wasted time and bandwidth psyching out the robot psychotherapist Eliza and playing text-based games like Adventure and Hunt the Wumpus, just like today's youth do but more primitively.

Comment: Internet Growth Follows Moore's Law


Info

Large ancient impact event discovered in Southeast Asia

Impact on Earth
© John R. Foster/Science Source
An artist’s representation of a large impact on Earth.
A kilometer-size asteroid slammed into Earth about 800,000 years ago with so much force that it scattered debris across a 10th of our planet's surface. Yet its impact crater remains undiscovered. Now, glassy remains believed to have come from the strike suggest the asteroid hit southeast Asia as our close ancestors walked the Earth.

"This impact event is the youngest of this size during human evolution with likely worldwide effects," says Mario Trieloff, a geochemist at the University of Heidelberg in Germany not involved in the research. Large impacts can disrupt Earth's climate by spewing dirt and soot high into the atmosphere, where it can block sunlight for months or even years.

Putative remains from this impact have been found before. Researchers have recovered chunks of glassy debris known as tektites across Asia, Australia, and Antarctica, and their distribution pattern suggests the asteroid struck Southeast Asia: The largest tektites-weighing more than 20 kilograms and presumably ejected the shortest distances from the impact-have been found there.

Microscope 1

Scientists successfully use virus to attack brain cancer tumors

medical research
© Thomas Peter / Reuters
Patients with aggressive brain tumours could be treated with a virus, according to a new study. Injected directly into the bloodstream, the virus could also boost their immune system in the process.

Scientists at the University of Leeds and the Institute of Cancer Research in London carried out successful trials on nine brain cancer patients using a 'reovirus'. The researchers found the virus could cross the protective membrane surrounding the brain to reach tumours.

The study is published in the journal Science Translational Medicine.

Previously it had been demonstrated that the virus could kill tumour cells without harming healthy cells. However, until now scientists thought it was unlikely that the virus would be able to pass from the bloodstream into the brain.

Pharoah

Secret writing in mummy cases is revealed by new scan technique

mummy face
© BBC News
Light of different frequencies can bring out writing that is obscured by the paste and plaster that holds mummy cases together.
Researchers in London have developed scanning techniques that show what is written on the papyrus that mummy cases are made from.

These are the decorated boxes into which the wrapped body of the deceased was placed before it was put in a tomb. They are made from scraps of papyrus which were used by ancient Egyptians for shopping lists or tax returns.

The technology is giving historians a new insight into everyday life in ancient Egypt.

The hieroglyphics found on the walls of the tombs of the Pharaohs show how the rich and powerful wanted to be portrayed. It was the propaganda of its time.
Mummy writing
© BBC News
Writing on the footplate reveals the mummy's name: Irethorru - translated means "the Eye of Horus is against my enemies".

Info

New study traces electric currents that flow along Earth's magnetic field

Earth’s magnetic field lines
© ESA/ATG Medialab
An illustration of Earth’s magnetic field lines, which are generated by the planet’s swirling liquid outer core and curve as they get buffeted by the solar wind.
The fact that planet Earth is essentially a giant magnet is not a great secret: A compass works because either end of its magnetized needle is constantly being drawn toward the North and South poles. Scientists believe that the Earth's magnetization is caused by a sea of liquid metal flowing past its solid iron core, creating electric currents and, in turn, magnetic fields.

The Earth's magnetic fields extend to the ionosphere-a layer of plasma and neutral gases about 50-500 kilometers above Earth's surface-and the magnetosphere, which starts at the outer edges of the ionosphere and stretches many thousands of miles into space. Magnetic fields from Earth and the Sun affect the behavior of charged particles in the magnetosphere.

Earth's magnetic field is highly conductive and carries charged particles in a predictable fashion along field lines (giving rise to aptly titled field-aligned currents). Starting in the early 1900s, scientists conceptualized an exchange of energy and momentum between the solar wind (a stream of charged particles emitted by the Sun that flows throughout the solar system) and our planet's own magnetic field.