Invisibility cloaking in 'perfect' demonstration

The trick included developing a diamond-shaped
cloaking region - invisible only from one direction

Scientists have succeeded in "cloaking" an object perfectly for the first time, rendering a centimetre-scale cylinder invisible to microwaves.

Many "invisibility cloak" efforts have been demonstrated, but all have reflected some of the incident light, making the illusion incomplete.

A Nature Materials study has now shown how to pull off the trick flawlessly.

However, the illusion only works from one direction and would be difficult to achieve with visible light.

The idea of invisibility cloaking got its start in 2006 when John Pendry of Imperial College London and David Schurig and David Smith of Duke University laid out the theory of "transformation optics" in a paper in Science, demonstrating it for the first time using microwaves (much longer wavelengths than we can see) in another Science paper later that year.

The papers sparked a flurry of activity to move the work on to different wavelengths - namely those in which we see.

As the "Where's my cloak of invisibility?" article points out, the field has moved on considerably since then.

But no effort to date has been able to achieve the "perfect" cloaking that the theory originally described.

The structures that can pull off this extraordinary trick of the light are difficult to manufacture, and each attempt has made an approximation to the theoretical idea that results in reflections.

It's like the card people in Alice in Wonderland... If they turn on their sides you can't see them but they're obviously visible if you look from the other direction - Prof David Smith (Duke University)

So someone would not see a cloaked object but rather the scene behind it - however, the reflections from the cloak would make that scene appear somewhat darkened.

Buzz Aldrin Points Out Inaccuracies in "After Earth"

Nearly a week after its release, M. Night Shyamalan’s “After Earth” has garnered a wide range of critics, including Buzz Aldrin who, despite calling it a great family drama, criticized it as unrealistic. And while the retired astronaut could go after a myriad of points, his main point of contention is the noise. (Photo : Reuters)

Nearly a week after its release, M. Night Shyamalan’s “After Earth” has garnered a wide range of critics, including Buzz Aldrin who, despite calling it a great family drama, criticized it as unrealistic. And while the retired astronaut could go after a myriad of points, his main point of contention is the noise.

“There was a lot of noise,” he told the Associated Press. “In space, you don’t get that much noise.”

The second man to step on the surface of the Moon further explained that even with his fellow astronaut beside him during that historic experience, the two communicated via headsets because “noise doesn’t propagate in a vacuum.”

Study: Increased carbon dioxide may lead to greener deserts

But researchers warn that CO2 fertilization could also result in other environmental shifts.

Increased levels of atmospheric carbon dioxide may have contributed to a gradual greening of some desert regions over the past 30 years, a process that will continue, according to a new study. But the authors warn that this "CO2 fertilization effect" could also have consequences for native plants and the wildlife that depends on them.

The study, published May 15 in the journal Geophysical Research Letters, was conducted by researchers from the Commonwealth Scientific and Industrial Research Organization (CSIRO), Australian National University and the Australian Research Council Centre of Excellence for Climate System Science.

The researchers went into this project knowing that satellite data collected since the 1980s has shown a worldwide increase in green foliage. Scientists around the world have theorized that this may have been a result of increased levels of CO2, a theory this new study supports. The authors of this new study looked at desert areas on four continents — where increases in vegetation would be easier to see and quantify — and created a mathematical model to calculate how they might have been affected by CO2 fertilization. With those calculations in hand, they then compared their predications to satellite imagery data from 1982 to 2010.

Mars radiation fears won't deter Nasa: the will to explore will prevail

People become astronauts knowing it's a dangerous job, and measures can be taken to minimise their radiation exposure

Local magnetic fields may provide some radiation protection in particular regions on Mars, but astronauts' living modules will need to be buried. Image: Nasa

How safe would a mission to Mars really be? As well as embarking on trips lasting several years in cramped craft with no breakdown cover, future interplanetary explorers will need to accept that their bodies will be zapped by high-energy particles, raising their risk of contracting cancer and other ill effects of radiation.

On Earth, we're all exposed to natural radiation from a variety of sources, including brazil nuts, bananas, and invisible radon gas. We'd be exposed to much higher doses from extraterrestrial sources if the Earth wasn't so well protected. The planet's magnetic field is carved into a teardrop-shaped bubble – the magnetosphere — by the solar wind that blows from the Sun. Although it contains some regions of higher radiation, the magnetosphere's overall effect is to shield life on Earth, and astronauts in low Earth orbit, from the harshest effects of cosmic radiation. Earth's atmosphere provides an additional buffer against all but the most energetic of particles. Astronauts travelling outside the magnetosphere, however, have to rely on the shell of their spacecraft to protect them from danger.

The Wow! Signal: Intercepted Alien Transmission?

SETI, the search for extraterrestrial intelligence, has seen astronomers scouring the sky for decades in hopes of receiving artificially generated radio signals sent by alien civilizations. But then, there’s a good chance we’ve already found just such a signal. And 1977 saw the most tantalizing glimpse ever.

Nicknamed the “Wow!” signal, this was a brief burst of radio waves detected by astronomer Jerry Ehman who was working on a SETI project at the Big Ear radio telescope, Ohio. The signal was, in fact, so remarkable that Ehman circled it on the computer printout, writing “Wow!” in the margin — and unintentionally giving the received radio signal the name under which it would become famous.

Despite a lot of effort, no identification has been found for the signal’s source, and no repeat signal has ever been found. It’s a complete mystery. The only conclusion that can be drawn is if the signal truly did originate in deep space, then it was either an astrophysical phenomenon of which we’ve never seen before, or it truly was an intercepted alien signal.

Do we need watches to tell us more than the time?

Big companies have been trying hard to make the long-awaited smartwatch "revolution" happen, so tick tock, what's taking so long?

Smartwatches are just not very smart when left to their own devices - they need to be connected to a smartphone for full functionality.

While the industry is growing quickly, nearly all still need a smartphone's Bluetooth connection to tell you much more than just telling the time.

What a smartwatch could potentially do, at least to thousands of children in the 80s, was typified by the wristwatch David Hasselhoff's character used in Knight Rider to control his car.

But the industry is still so new there are many different approaches.

Apple's smartwatch is rumoured to exist 
already... or not exist at all. Or exist 
sometime soon

"Smartwatches can already be split into three or four categories," says senior analyst Josh Flood, of ABI Research.

"There are notification watches - the really basic ones which just link to the phone, voice-capable smart watches which is a really cool idea and health and fitness smartwatches for heart rate and running."

Others see even greater potential.

"Through NFC [near field communication], could you transfer travel cards to the watch?" says Skooks Pong, vice president of Synapse, a company working with Nike to develop its FuelBand activity tracker/watch hybrid.

"I think the tipping point will happen at the back end of this year” - Josh Flood (ABI Research)

"Who knows where it will go but I would love to be at a point where I could walk into the store, tap my wrist and pay for whatever it is I'm buying."

'Smart skin' hope for touch sensor

Scientists have made a step forward in their ability to mimic the sense of touch.

A team from the US and China made an experimental array that can sense pressure in the same range as the human fingertip.

The advance could speed the development of smarter artificial skin capable of "feeling" activity on the surface.

The sensors, which are described in Science magazine, could also help give robots a more adaptive sense of touch.

Using bundles of vertical zinc oxide nanowires, the researchers built arrays consisting of about 8,000 transistors.

"This is a fundamentally new technology that allows us to control electronic devices directly using mechanical agitation" - Zhong Lin Wang (Georgia Institute of Technology)

Each of the transistors can independently produce an electronic signal when placed under mechanical strain.

NASA's Orion space program aims to renew lofty goals

When a rocket carrying a new crew vehicle lifts off at Cape Canaveral next year, it will be the first big step in a decades-long odyssey to see humans travel farther into space than ever before.

That ambitious program, called Orion, has goals that sound as if they were lifted from the pages of a sci-fi novel: the capture of near-Earth asteroids, bringing them into lunar orbit, a return to the moon, and putting astronauts on Mars.

Baby steps in the odyssey are already being taken in labs and testing facilities across the nation. One is at Aerojet in Rancho Cordova, Calif. There, inside solemn buildings surrounded by fields of dry grass, rockets destined for the dark reaches of space are being designed and tested.

Aerojet is supplying the large and small rockets that will allow the Orion multipurpose crew vehicle, designed to house four astronauts, to orient itself during space flight and during the re-entry to Earth's atmosphere, said Sam Wiley, head of human space at Aerojet.

The company is also supplying a launch-abort system, which would pull the crew module to safety in a life-threatening event during launch.

Countdown: The Coldest Places on Earth

Intro

Venturing outside in the cold this winter, with record-breaking low temperatures stretching from Maine to southern Florida, may take some courage, but these recent lows are nothing compared to the ones on this list.

Check out the places in the world that hold the records for the coldest temperatures ever measured on Earth.

8. International Falls, Minnesota, United States (- 40 Fahrenheit/- 40 Celsius)

International Falls is so serious about its status as one of the coldest places in the continental United States that it has actually taken another town to court over the title.

In 2002, International Falls took Fraser, Colorado, to court in order to finally settle who had claim to the title "Icebox of the Nation," according to a report from the BBC. They now celebrate that win by hosting the annual four-day Icebox Days festival, which includes events such as frozen turkey bowling, snow-sculpting and candlelit skiing.

While it is in fact only the second coldest place in the continental United States, International Falls boasts the lowest average temperature in the country, hovering between 32 and 36 degrees F (0 and 2 degrees C).

NASA’s TESS will search for habitable ‘super earths’

Now that astronomers have discovered planets around other stars, and judged that those planets could have Earth-like conditions, the next step is to find out for sure. While we can’t visit them, astronomers hope to gather clues via telescopes.

The Transiting Exoplanet Survey Satellite (TESS), a new space-based telescope that NASA expects to launch in 2017, will conduct an “all-sky survey,” scrutinizing stars throughout the sun’s neighborhood, to find any yet-undiscovered exoplanets that may orbit them. According to George Ricker, the TESS mission’s principal investigator, the TESS sky scan will cover 400 times as much sky as any previous mission.

The Kepler telescope revealed hundreds of potential exoplanets in its four years in orbit. Unfortunately, most of those planets are in star systems that are a thousand or more light-years away from Earth. Such vast distances will make it impossible for us to study them in any greater depth. The TESS mission, by contrast, will attempt to find more promising study subjects by focusing on stars closer to Earth. They might turn up in orbit around one or more of the many red-dwarf stars and seven sun-like stars that astronomers have all calculated to be within 20 light-years of Earth.