SCI-TECH 20WEDNESDAY, NOVEMBER 25, 2015

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AN ULTRA-THIN CAMERA WITH NO LENSFlatCam is little more than a thin sensor chip with a mask that replaces lenses inatraditional camera. Making it practical are sophisticated computer algorithmsthat process what the sensor detects and converts them into images and videos.

T here may be long filaments of dark mat-ter or “hair” on our Earth, suggests newresearch, adding further study is neededto unlock the mysteries of the nature ofdark matter on our planet.

Dark matter is an invisible, mysterious sub-stance that makes up about 27 per cent of all mat-ter and energy in the universe.

Regular matter, which makes up everythingwe can see, is only five per cent of the universe.The rest is dark energy, a phenomenon associat-ed with the acceleration of our expanding uni-verse.

According to previous calculations and sim-ulations, dark matter forms “fine-grainedstreams” of particles that move at the same ve-locity and orbit galaxies such as ours.

“A stream can be much larger than the solarsystem itself and there are many differentstreams crisscrossing our galactic neighbour-hood,” said Gary Prezeau from NASA’s Jet Pro-pulsion Laboratory in Pasadena, California.

He found that when a dark matter streamgoes through a planet, its particles focus into anultra-dense filament or “hair” of dark matter.

In fact, there should be many such hairssprouting from the Earth.

A stream of ordinary matter would not gothrough the Earth and out the other side, but fordark matter, the Earth is no obstacle.

According to Prezeau’s simulations, theEarth’s gravity would focus and bend the streamof dark matter particles into a narrow, dense hair.

Hairs emerging from planets have both“roots,” the densest concentration of dark mat-ter in the hair, and “tips” where the hair ends.

When particles of a dark matter stream passthrough the Earth’s core, they focus at the “root”

of a hair, where the density of the particles isabout a billion times more than average.

The root of such a hair should be around onemillion kilometres away from the surface, ortwice as far as the moon.

The stream particles that graze the Earth’ssurface will form the tip of the hair, about twiceas far from the Earth as the hair’s root.

“If we could pinpoint the location of the rootof these hairs, we could potentially send a probethere and get a bonanza of data about dark mat-ter,” Prezeau noted.

A stream passing through Jupiter’s corewould produce even denser roots: almost onetrillion times denser than the original stream, ac-cording to Prezeau’s simulations.

“Dark matter has eluded all attempts at directdetection for over 30 years. The roots of darkmatter hairs would be an attractive place to look,given how dense they are thought to be,” addedCharles Lawrence, chief scientist for JPL.

Earth may have ‘hairy’dark matter: NASAWhen dark matter goes through a planet, the stream particles focus into an ultra-dense filament or“hair” of dark matter. Researchers believe that there should be many such hairs sprouting from the Earth

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Left: An illustration showing Earth surrounded by dark matter “hairs”; Right: An artist’s rendering of what dark matter hairs might look like around Earth

NASA/JPL-Caltech

G oogle has developed a prototype wearabledevice based on the communicator in StarTrekwhich uses a microphone to listen to a

user’s voice and can use Bluetooth to send thosecommands to another device.

In science fiction, Captain Picard and hiscrew used their lapel pins to talk to the AI andcrew onboard the Starship Enterprise.

Google’s circular prototype device connectsto a smartphone through Bluetooth, Amit Sing-hal, senior vice president and executive incharge of the firm’s search initiatives, told Timemagazine.

The concept was intended to test out how us-ers might interact with voice search in new ways.Worn on the chest, the Google pin is activated

with a light tap.The prototype might output sound through

an onboard speaker or by connecting to head-phones. The idea was to make it easier to query toGoogle without fishing out a cell phone.

“I always wanted that pin,” Singhal wasquoted as saying. “You just ask it anything and itworks. That’s why we were like, ‘Let's go proto-type that and see how it feels.’”

The device hasn’t left the testing phase but il-lustrates how far Google is willing to go to chartthe future of search.

The company is trying to redefine the waypeople access information through voicesearch, which is getting more adept at under-standing natural language, Timesaid. MM

Google developed Star Trek-like communicator device

The prototype was spearheaded by Amit Singhal,head of Google’s search initiatives

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REAL BOXING 2: CREEDInfinity Blade, Real Racing, Modern Combat: there are afew games on mobile that stand out because of just howgood they look, and Real Boxing is right up there. Real Box-ing 2: Creed isn’t just a sequel, but also a tie-in to the mo-vie Creed. There’s a complete story mode, where you cre-ate your own boxer, train with the legendary Rocky Balboa,and aim to become world champion across single and mul-tiplayer modes. It’s definitely worth the download, just aslong as your device can handle it.

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R esearchers at Duke and Stanford Universitieshave devised a way to watch the details of neu-rons at work, pretty much in real time.

Every second of every day, the 100 billion neu-rons in your brain are capable of firing off a burst ofelectricity called an action potential up to 100 timesper second. For neurologists trying to study how thisoverwhelming amount of activity across an entirebrain translates into specific thoughts and beha-viours, they need a faster way to watch.

Existing techniques for monitoring neurons aretoo slow or too tightly focused to generate a holisticview. But in a new study, researchers reveal a tech-nique for watching the brain’s neurons in actionwith a time resolution of about 0.2 milliseconds – aspeed just fast enough to capture the action poten-tials in mammalian brains.

“We set out to combine a protein that can quicklysense neural voltage potentials with another proteinthat can amplify its signal output,” said YiyangGong, assistant professor at Duke.

“The resulting increase in sensor speed matcheswhat is needed to read out electrical spikes in thebrains of live animals.”

Gong and his colleagues sought out a voltage sen-sor fast enough to keep up with neurons. After sever-al trials, the group landed on one found in algae, andengineered a version that is both sensitive to voltageactivity and responds to the activity very quickly.

The amount of light it puts out, however, wasn’tbright enough to be useful in experiments.

To meet this engineering challenge, Gong fusedthe newly engineered voltage sensor to the brightestfluorescing protein available at the time. He linkedthe two close enough to interact optically withoutslowing the system down.

“When the voltage sensing component we engi-neered detects a voltage potential, it absorbs morelight,” said Gong. “And by absorbing more of thebright fluorescent protein’s light, the fluorescence ofthe system dims in response to a neuron firing.”

The new sensor was delivered to the brains ofmice using a virus and incorporated into fruit fliesthrough genetic modification. In both cases, the re-searchers were able to express the protein in selectedneurons and observe voltage activity.

They were also able to read voltage movements indifferent sub-compartments of individual neurons,which is very difficult to do with other techniques.

“Being able to read voltage spikes directly fromthe brain and also see their specific timing is veryhelpful in determining how brain activity drives ani-mal behaviour,” said Gong. AGENCIES

New sensor sees nerveaction as it happens

Pune Mirror, November 25, 2015. Pp.20