Issue no. 19, 2012
Published: Jun 29, 2012 |
|
 Twisted beams of light transmit data at dramatic speeds |
| Evolution could generate new semiconducting structures |
| Privately funded spacecraft will look for dangerous asteroids |
| Frequency comb helps kill dangerous bacteria |
| Pottery 20,000 years old found in a Chinese cave |
| Facebook study reveals what makes someone a leader |
| Future-predicting system cuts app loading time |
| The rock, paper, scissors playing robot that never loses |
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| Twisted beams of light transmit data at dramatic speeds |
Normal broadband cable supports data transfer at a speed of up to 30
megabits per second. But a multi-national team of scientists has
developed a method that transmits data 85 thousand times faster than
broadband cable.
The team used twisted beams of light to transmit data at 2.56 terabits
per second. The researchers achieved this by using beam-twisting 'phase
holograms' to manipulate eight beams of light. A phased hologram
refracts light by means of different thicknesses of a transparent
substance.
As part of the experiment the researchers twisted each of the beams into
a DNA-like helical shape and propagated them in free space. Their
demonstration transmitted data over open space in a lab, by attempting
to simulate communications between satellites in space.
The work could potentially be used in the building of high-speed
satellite communication links and short free-space terrestrial links.
Further research could lead to ways the finding could be adapted for use
in fibre-optic cables that transmit much of the internet's information. |
| RTTNews / Nature Photonics
Jun 28, 2012 |
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| Evolution could generate new semiconducting structures |
The best semiconductors are grown, not made. At least, this might one
day be the case. Proteins that can build silica nanostructures on our
behalf have been 'evolved' in the lab. The structures could find a use
in the semiconductor industry.
Researchers at the University of Leeds, UK, wondered whether proteins
that evolved to help build animal skeletons could be used to grow new
electronics components. The team chose silicateins - proteins that build
the silica skeletons of marine sponges - as the basis for their work.
Using DNA amplification techniques, they grew millions of strands of DNA
that code for silicateins. Mutations arise naturally during the process,
so the final pool of DNA contained enough variation to ensure that some
of the silicateins would build different kinds of mineral structures.
The researchers then attached the DNA to polystyrene microbeads and
placed them in a solution containing a silicon-rich compound. The team
was looking to select proteins that could draw silicon out of the
solution to build silica structures around the beads, while still
allowing access to the DNA on the surface of the bead. This would make
it easy to collect and amplify the DNA that made the most promising
structures. The end product? Proteins that built silica structures
unlike any seen in nature.
With further evolution it should be possible to grow silica structures
of the right size and shape for use in technological applications. |
| News Scientist / PNAS
Jun 26, 2012 |
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| Privately funded spacecraft will look for dangerous asteroids |
An American non-profit organisation has announced a space mission to map
the inner solar system for evidence of asteroids that could strike the
Earth. The five-and-a-half-year voyage, which the organisation describes
as the first privately funded deep-space mission, is due for launch in
2016 or 2017.
The ambitious plan is organised by the B612 Foundation. It aims to 'open
up the frontier to space exploration and protecting humanity on Earth'.
That protection focuses on mapping the orbits of the tens of thousands
of near-Earth asteroids with diameters of at least 140m that could
strike the Earth with an explosive force of at least 100 megatonnes of
TNT. That is 3.5 times the diameter of the object that struck Tunguska,
Siberia, in 1908, uprooting up to 80 million trees and shattering
windows hundreds of kilometres away.
According to B612, more than 98% of such asteroids remain totally
unknown to astronomers. The mission aims to find and track more than 90%
of them. The spacecraft, called Sentinel, will take off from NASA's
Kennedy Space Center in Florida. A gravitational slingshot manoeuvre off
Venus will put the craft into an orbit around the Sun close to that of
Venus. The craft will carry an infrared telescope to map the locations
and trajectories of Earth-crossing asteroids.
The telescope will scan the entire night half of the sky every 26 days
to identify every moving object. Repeated observations of individual
asteroids will permit astronomers to calculate their orbits and predict
their positions accurately for a century or more in the future. |
| Physics World
Jun 28, 2012 |
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| Frequency comb helps kill dangerous bacteria |
Scientists in the US have used an optical-frequency comb - a laser that
emits light at a range of equally spaced frequencies, like the teeth on
a comb - to monitor how well a device designed to kill dangerous
bacteria does its job. The comb was used to measure the concentrations
of ozone, hydrogen peroxide and other reactive molecules in the stream
of air and cold plasma produced by the decontamination device. The study
reveals that decontamination is most efficient when both a plasma and
hydrogen peroxide are present in the stream.
'Cold-air plasmas' - room-temperature gases of ionized air molecules -
are widely used to kill dangerous bacteria, both in medical and
food-processing environments. While the technique is good at dealing
with antibiotic- and heat-resistant bacteria, the devices can be even
more potent if the plasma is combined with an antibacterial chemical
such as hydrogen peroxide. But understanding why this process occurs and
how it could be improved is not easy because accurately measuring the
relative abundances of different molecules in the stream - and how they
interact - is tricky.
Researchers at the University of Colorado have shown that an
optical-frequency comb can get round this problem to study molecules in
the decontaminating stream. When light from the comb passes through the
stream, the presence of a specific molecule or ion is signified by the
absorption of a specific set of teeth. According to the team, the comb
offers the unique capability of an extremely sensitive measurement and
one that also yields information about the interaction dynamics, since
many molecules can be simultaneously observed on short timescales. |
| Physicsworld / IEEE Transactions on Plasma Science
Jun 22, 2012 |
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| Pottery 20,000 years old found in a Chinese cave |
Pottery fragments found in a south China cave have been confirmed to be
20,000 years old, making them the oldest known pottery in the world,
archaeologists say.
The findings add to recent efforts that have dated pottery piles in east
Asia to more than 15,000 years ago, refuting conventional theories that
the invention of pottery correlates to the period about 10,000 years ago
when humans moved from being hunter-gathers to farmers.
The research by a team of Chinese and American scientists also pushes
the emergence of pottery back to the last ice age, which might provide
new explanations for the creation of pottery.
The ancient fragments were discovered in the Xianrendong cave in south
China's Jiangxi province. |
| Yahoo / AP / Science
Jun 28, 2012 |
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| Facebook study reveals what makes someone a leader |
Every group of friends has its leaders and its followers, those who are
able to influence their peers and those who can't resist. Now a study of
over one million Facebook users reveals just who wields the most peer
power, with men showing greater influence than women, while younger
people are less influential than their older counterparts. Knowing what
makes someone influential could of course help advertisers spread their
products through social media, but it can also be used more
altruistically, such as promoting HIV testing in Africa.
Researchers from New York University studied influence by watching how
use of a film-rating app spread through Facebook users. Starting with a
seed group of 7,730 users, the researchers designed the app to randomly
send messages to the app users' friends, encouraging them to also
install the app. Just under 42,000 messages were sent out to a random
selection of the initial groups' 1.3 million friends, resulting in
nearly 1,000 new app users. This random selection of who gets the
message allowed the researchers to avoid common pitfalls in measuring
influence, such as homophily bias - the principle that we tend to make
friends with people like ourselves.
Analysing the results in combination with users' Facebook profile data
revealed a number of insights into which people are the most
influential. Men are 49% more influential than women, but women are 12%
less susceptible to influence than men, and they exert 46% more
influence over men than over other women. Influence also increases with
age, with people over 31 being 51% better at convincing their friends
than those under 18. Relationship status also plays a role. Single
individuals are 113% more influential than those in a relationship and
128% more than those who define their relationship status as 'it's
complicated'. On the flip side, susceptibility rises with increasing
relationship commitment - up until you get married. |
| New Scientist / Science
Jun 21, 2012 |
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| Future-predicting system cuts app loading time |
Does your favourite app seem to be taking longer to load than it used
to? That may be due to ever-richer graphics and overloaded cellphone
networks, which take their toll on smartphone apps and increase the time
they take to boot and retrieve information from the network on, say,
train times or the weather. A way to make them boot faster, developed at
the University of Massachusetts at Amherst, could mean your app might
one day be ready and waiting for you the moment before you need it.
The team have borrowed a trick from computer science to achieve speedier
loading. Called predictive caching, it involves guessing which software
routines are most likely to be needed for the next stage of a
computerised process, so that the right app is primed to run when called
on, without booting from scratch. The system uses the phone's location
and motion sensors to learn when the user typically runs the app.
Imagine that, as you walk to a railway station each day, you normally
get to a certain street corner and open a train times app to see if the
trains are running to schedule. The software checks the time you usually
do this, senses that you are walking and preloads the app, with the
current train info retrieved by the time you arrive at the corner on
which you normally request it.
In tests, the software cut 6 seconds from the average 20-second boot-up
time for apps on Windows phones - although it gobbled 2% of the battery
per day while doing so. |
| New Scientist
Jun 27, 2012 |
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| The rock, paper, scissors playing robot that never loses |
Most of us think of the game rock, paper, scissors as a game of chance.
Some of us, like Douglas Walker, co-author of the Rock Paper Scissors
Strategy Guide, consider it a game of physical and psychological skill.
And then there are the scientists at the University of Tokyo's Ishikawa
Oku Laboratory, makers of the Janken robot, who have turned the game
into an impossible endeavour. You cannot beat the Janken robot at rock,
paper, scissors. The robot will always win.
So how does the robot always win? The answer is simple: The robot
cheats. The researchers explain that the robot makes its move one
millisecond after its human opponent has made his or her move. The wrist
joint angle of the robot hand is controlled based on the position of the
human hand. The vision recognises one of rock, paper and scissors based
on the shape of the human hand. After that, the robot hand plays one of
rock, paper and scissors so as to beat the human being in 1ms.
A robot that will win rock, paper, scissors 100% of the time sounds kind
of annoying to us, but the researchers said the technology shows the
possibility of cooperation between humans and machines in just a few
milliseconds. The researchers suggest this technology can be applied to
motion support of human beings and cooperation work between human beings
and robots without time delay. |
| Los Angeles Times
Jun 28, 2012 |
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