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Robot

Shape-shifting robot a step closer with development of unique gallium alloy

A metal alloy that powers its own movement and deforms to get through tight spots could let us to build a Terminator 2 style robot (minus homicidal tendencies)


Hasta la vista, baby. A real-life T-1000, the shape-shifting liquid-metal robot from Terminator 2, is a step closer, thanks to a self-powered liquid metal motor.

The device is surprisingly simple: just a drop of metal alloy made mostly of gallium - which is liquid at just under 30 °C - with some indium and tin mixed in. When placed in a solution of sodium hydroxide, or even brine, and kept in contact with a flake of aluminium for "fuel", it moves around for about an hour. It can travel in a straight line, run around the outside of a circular dish, or squeeze through complex shapes.

"The soft machine looks rather intelligent and [can] deform itself according to the space it voyages in, just like [the] Terminator does from the science-fiction film," says Jing Liu from Tsinghua University in Beijing, China. "These unusual behaviours perfectly resemble the living organisms in nature," he says, adding that they raise questions about the definition of life.

When they first saw the drop move, Liu and colleagues weren't sure how it was able to do so. Experiments revealed two mechanisms at play. Some of the thrust stems from a charge imbalance across the drop, which in turn creates a pressure differential between the front and the back that pushes it forward. The aluminium also reacts with the sodium hydroxide, releasing hydrogen bubbles which drive the drop even faster.

Bulb

Free will? Same stimulus doesn't always produce same response, even in worms


Even worms have free will. If offered a delicious smell, for example, a roundworm will usually stop its wandering to investigate the source, but sometimes it won't.
Just as with humans, the same stimulus does not always provoke the same response, even from the same individual. New research at Rockefeller University, published online in Cell, offers a new neurological explanation for this variability, derived by studying a simple three-cell network within the roundworm brain.

"We found that the collective state of the three neurons at the exact moment an odor arrives determines the likelihood that the worm will move toward the smell. So, in essence, what the worm is thinking about at the time determines how it responds," says study author Cori Bargmann, Torsten N. Wiesel Professor, head of the Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior. "It goes to show that nervous systems aren't passively waiting for signals from outside, they have their own internal patterns of activity that are as important as any external signal when it comes to generating a behavior."

The researchers went a step deeper to tease out the dynamics within the network. By changing the activity of the neurons individually and in combination, first author Andrew Gordus, a research associate in the lab, and his colleagues could pinpoint each neuron's role in generating variability in both brain activity and the behavior associated with it.

The human brain has 86 billion neurons and 100 trillion synapses, or connections, among them. The brain of the microscopic roundworm Caenorhabditis elegans, by comparison, has 302 neurons and 7,000 synapses. So while the worm's brain cannot replicate the complexity of the human brain, scientists can use it to address tricky neurological questions that would be nearly impossible to broach in our own brains.

Binoculars

Another myth busted: No connection between hip width and efficient locomotion

Among the facts so widely assumed that they are rarely, if ever studied, is the notion that wider hips make women less efficient when they walk and run.

For decades, this assumed relationship has been used to explain why women don't have wider hips, which would make childbirth easier and less dangerous. The argument, known as the "obstetrical dilemma," suggests that for millions of years female humans and their bipedal ancestors have faced an evolutionary trade-off in which selection for wider hips for childbirth has been countered by selection for narrower hips for efficient locomotion.

A new study, however, shows that what was widely assumed to be fact is, in actuality, almost entirely incorrect.

A new study, conducted by researchers at Harvard in conjunction with colleagues at Boston University and Hunter College, found no connection between hip width and efficient locomotion, and suggests that scientists have long approached the problem in the wrong way. The study is described in a March 11 paper published in PLOS ONE.

"This idea, that pelvic width for birth and pelvic width for locomotion are connected, is deeply ingrained in this discipline," said Anna Warrener, first author of the study and a post-doctoral fellow working in the lab of Daniel Lieberman, the Edwin M. Lerner II Professor of Biological Sciences and Chair of the Department of Human Evolutionary Biology. "Everyone thinks they know this is true...but it's wrong, and it's wrong for two reasons.First, the way we had modeled the forces involved didn't make sense. Second, we found that you can't predict, from the width of the pelvis, how much energy someone is using, so we've been looking at this biomechanical problem entirely wrong."

Comment: True science: "Good science is about taking a critical look at things we take for granted."

How true! Often dearly held "science" turns not to be as straight forward as claimed, and sometimes it is plainly wrong.


Heart

New bionic heart would work without beating

© BiVACOR
Scientists at the Texas Heart Institute claim that they are co-developing a bionic heart that can perfectly replicate the function of its biological counterpart, but without actually beating.

The researchers, who are working on the heart along with Houston-based private-sector medical research and engineering firm BiVACOR, told ABC News that the average human heart needs to beat 42 million times per year. An artificial heart that had all of the moving parts required to beat would wear out in a hurry, BiVACOR chief medical officer Dr. William Cohn said.

Like a soda can with magnets

The new bionic heart would only have one moving part and would transport blood through the body using magnets instead of pumping it, they explained. A prototype that has been used in large animals allows them to live for a month and even exercise on a treadmill for one month before they are culled to examine its impact on their brain and other organs.

"The device has performed in many respects better than any artificial heart anybody has come up with in the last 50 years," Cohn told ABC News, noting that he and his colleagues consider it the "first legitimate shot... for a permanent mechanical replacement for the failing human heart." He added that "kidney function, lung function, everything works beautifully throughout."

While the device, which is approximately half the size of a soda can, is implanted in a patient's chest, it has a battery-operated controller that remains outside his or her body, a recent Lubbock Online blog said. It features a spinning disk with fins suspended by a pair of magnetic fields that prevent it from touching anything, and rotates an estimated 2,000 to 3,000 times a minute.

Galaxy

The Milky Way galaxy may be more enormous than we ever imagined

How big is the Milky Way? Way bigger than we thought, it seems.

Surprising new research suggests that our home galaxy is about 50 percent bigger than previously thought, spanning some 150,000 light-years across rather than the 100,000 light-years that has been the generally accepted number.

We know quite a lot about the Milky Way, so how can it be that we're just now realizing that we were so wrong about its size? It turns out that what seemed to be concentric rings of stars surrounding our galaxy's bulging center are instead concentric ripples--and that means the galaxy doesn't end where we thought it did.

"If there are ripples, then it looks like the number of stars in the (presumed flat) disk drops off quickly, and then farther out where the disk ripples back up it looks like a detached ring of stars appears," Dr. Heidi Newberg, professor of physics, applied physics, and astronomy at Rensselaer Polytechnic University in Troy, NY, told The Huffington Post in an email. "We now understand that the galaxy didn't end; the disk is just going up and down--in and out of our view."
© Renssellaer polytechnic Institiute
Illustration showing the density of light in the Milky Way.

Comet

Giant comets and mass extinctions of life: Looking at the crater record


Comment: The full paper can be viewed here.


Abstract
I find evidence for clustering in age of well-dated impact craters over the last 500 Myr. At least nine impact episodes are identified, with durations whose upper limits are set by the dating accuracy of the craters. Their amplitudes and frequency are inconsistent with an origin in asteroid breakups or Oort cloud disturbances, but are consistent with the arrival and disintegration in near-Earth orbits of rare, giant comets, mainly in transit from the Centaur population into the Jupiter family and Encke regions. About 1 in 10 Centaurs in Chiron-like orbits enter Earth-crossing epochs, usually repeatedly, each such epoch being generally of a few thousand years' duration. On time-scales of geological interest, debris from their breakup may increase the mass of the near-Earth interplanetary environment by two or three orders of magnitude, yielding repeated episodes of bombardment and stratospheric dusting. I find a strong correlation between these bombardment episodes and major biostratigraphic and geological boundaries, and propose that episodes of extinction are most effectively driven by prolonged encounters with meteoroid streams during bombardment episodes. Possible mechanisms are discussed.

Comment: As Napier writes in his conclusion, "positive evidence for such [bombardment] episodes appears in the impact cratering record. They are found to be tightly correlated with substantial marine extinctions at the level of genera. ... it is suggested here that prolonged atmospheric perturbations arising from fireball storms and dusting are the most energy-efficient means of collapsing food chains, yielding both marine and land extinctions."

See also: Track this: Unseen 'dark comets' may pose threat to Earth


Saturn

Further evidence of Solar System-wide 'Climate Change': A "curious abundance" of methane detected spewing from Saturn's icy moon Enceladus

© Southwest Research Institute
Illustration depicts the potential origins of methane found in the plumes of the Saturn moon, Enceladus. Scientists believe the plumes originate from an internal liquid-water ocean in the south polar region.
NASA's Cassini spacecraft has measured a curious abundance of methane spewing into the atmosphere of Saturn's icy moon Enceladus. A team of American and French scientists published findings in Geophysical Research Letters suggesting two scenarios that could explain the methane abundance observed in the plumes.

In 2005 Cassini's magnetometer and imaging data revealed the surprising existence of geysers in the south polar region ejecting water vapor into space. Scientists now believe that Enceladus harbors an internal liquid-water ocean under tons of icy crust, and that the plumes originate there. Analyzing the composition of the plumes, therefore, can provide a direct window to what is happening in the inner ocean. Cassini has since flown through the plumes, allowing scientists to determine that these watery geysers contain other volatile species, including hydrogen, carbon dioxide, ammonia, and methane. Volatiles are chemical elements and compounds with low boiling points that are associated with a planet's or moon's crust or atmosphere.

"We modeled what would happen to those species in a subsurface ocean in Enceladus," said the paper's lead author Alexis Bouquet, a French graduate student at the University of Texas at San Antonio. "With high pressures expected in a subsurface ocean, clathrates could form and deplete the ocean of volatiles."

Comment: So now we have a "curious abundance" of methane spewing into the atmosphere of Saturn's icy moon Enceladus. Only a few months ago we had 'methane outgassing on Mars'.

There has been increased methane outgassing here on Earth too recently:

Arctic Ocean leaking methane faster than anticipated
Vast methane plumes discovered escaping from Arctic seafloor north of Siberia
New climate change threat: Arctic seabed releases millions of tons of methane into atmosphere

As well as "increasingly stormy" conditions on Uranus, last year we saw increased volcanic activity on Jupiters moon Io, scientists have been puzzled by the wobble of Saturn's moon Mimas and a major increase in asteroid activity has seen MIT astronomers upgrade the solar system from stable to dynamic

What is causing these recent solar system-wide 'climate changes'?

Could it be part of an overall 'grounding' of our solar system, caused perhaps by the close approach of the system's Twin Sun? Clearly something BIG is producing systemic effects, rather than isolated effects on individual planets.


Info

'Underground' ocean confirmed on Jupiter's largest moon

© NASA, ESA, G.Bacon (StScl)
An artist's impression of aurora on Ganymede.
Scientists using the Hubble Space Telescope have confirmed that the Jupiter-orbiting moon Ganymede has an ocean beneath its icy surface.

The finding resolves a mystery about the largest moon in the solar system after NASA's now-defunct Galileo spacecraft provided hints that Ganymede has a sub-surface ocean during exploration of Jupiter and its moons from 1995 to 2003.

Scientists say it took some detective work to confirm the discovery.

Like Earth, Ganymede has a liquid iron core that generates a magnetic field, though Ganymede's field is embedded within Jupiter's magnetic field. That sets up an interesting dynamic with telltale visuals -- twin bands of glowing aurora around Ganymede's northern and southern polar regions.

As Jupiter rotates, its magnetic field shifts, causing Ganymede's aurora to rock. Scientists measured the motion and found it fell short. Using computer models, they realised that a salty, electrically conductive ocean beneath the moon's surface was counteracting Jupiter's magnetic pull.

"Jupiter is like a lighthouse whose magnetic field changes with the rotation of the lighthouse. It influences the aurora," says geophysicist Joachim Saur, with the University of Cologne in Germany.

"With the ocean, the rocking is significantly reduced," says Saur.

Scientists ran more than 100 computer models to see if anything else could be having an impact on Ganymede's aurora. They also repeated the seven-hour, ultraviolet Hubble observations and analysed data for both belts of aurora.

"This gives us confidence in the measurement," says Saur.

TV

12 top Russian inventions that changed the world

Russian inventors have contributed generously to the development of global scientific thought. Many of their inventions have literally transformed the world, enabling us to enjoy such blessings of civilisation as aircraft, cars, computers and television. RIR presents a dozen of such revolutionary innovations that have become an integral part of modern existence.

Caterpillar tracks, track assembly

In 1837, Russian army captain Dmitry Zagryazhsky came up with drawings of a caterpillar drive and applied to the Ministry of Finance for a patent for his invention of a "carriage with a flat chain mechanical caterpillar". He was granted a patent but his invention did not interest manufacturers at that time and the patent was annulled in 1839. Much later, in 1877, Russian peasant and self-taught inventor Fyodor Blinov completed Zagryazhsky's unfinshed task and created a wagon that moved on caterpillars. This invention gave the green light to production of tractors and, subsequently, of tanks.

Image
© ITAR-TASS

Comment: Take note of the time period when most of these ideas or inventions were developed: late imperial Russia.


Eye 1

New procedure may turn brown eyes blue

© Thinkstock
A new technique may be able to turn brown eyes blue. But is it safe?
The idea to use lasers to turn brown eyes blue was born in an unlikely place: a dermatologist's office.

Driving home after having some pigment spots removed from his skin by laser, Gregg Homer wondered what would happen if you used a similar laser on the eyes.

An inventor who had a Ph.D in biology, Homer did a little research and quickly realized the potential of the idea: a study in the 1980's had shown that underneath every brown eye is a blue eye. And that brown layer, Homer discovered, appeared to be superficial enough that it could, theoretically, be removed.

"I went back to my dermatologist and said, I've got a question for you," Homer told Discovery News. "What would happen if you used this on an iris?"

The dermatologist eventually joined his board of investigators, and now, almost 20 years later, the surgery is going through human testing in Costa Rica via Homer's company called Stroma.

The original idea, that the frequency of the green laser is such that it passes straight through the cornea and is only absorbed by dark color, makes it "incredibly safe and incredibly differentiating," Homer said.

The change isn't immediate; the laser is set at a low energy so that the blue eye is revealed over a couple of weeks.

While there have been no adverse effects in the 37 people who have had one eye treated in trials outside of the U.S., Homer said, it's too early to say for certain what long-term effects the procedure could have. Ophthalmologists say the primary health concern, at least theoretically, is glaucoma.