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June 10, 2013

Animal invisibility cloak: Cat and fish vanish

Screen Shot 2013-06-10 at 6.23.45 PM

Videre est credere.

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Or maybe not.

From The Guardian:


Chinese scientists demonstrate new light-bending technology that could have applications in telecommunications


Scientists have shown off their latest "invisibility cloak" by making a pet goldfish and a small cat vanish from plain sight.

The device is crude and unlikely to pass muster with the pupils of Hogwarts, but researchers said it marked a significant step forward in the science of the unseen.

In video footage of the device in action, a goldfish suddenly appears as it swims out of a cloak submerged in its tank. In another clip, the lower half of a cat disappears as it steps inside a cloak placed on a table.

Scientists led by Baile Zhang at Nanyang Technological University in Singapore created the cloaks from thin panels of glass that make objects invisible by bending light around them.

Though rudimentary — the devices only hide objects from certain angles, and in both cases the cloaks themselves were partially visible — they are better than earlier versions that worked only with polarized light, or with microwaves instead of the visible wavelengths that humans see in.

In a report on the work, the scientists say operators could adjust the cloaks to make objects invisible from any line of sight. They add that the devices could have "important security, entertainment, and surveillance applications."

The first cloak the scientists tested was a clear hexagonal device that was placed in a tank of water containing a goldfish. The fish swam into the cloak, and appeared to need some encouragement to re-emerge.

"When swimming inside the cloak, the goldfish becomes invisible and does not block the scene of green plants behind the cloak," the scientists write. The hexagonal cloak could hide objects from six different directions.

The second cloak was designed to hide objects from a person stood directly in front or behind. This time the researchers projected an outdoor scene of plants and flowers onto a screen and put the cloaking device in front. When an obliging cat wandered along and sat in the cloak, its lower body vanished.

In one clip, a yellow butterfly that is flitting between flowers on the screen can still be seen through the body of the cat.

The cloaks are based on technology first developed by Sir John Pendry at Imperial College London. In 2006, he described how transformation optics could allow scientists to steer light around objects, and so make them disappear from view.

Early designs of cloaks used finely-structured sheets of materials that behave differently to glass, for example, by bending light the wrong way. Later, in 2011, Pendry teamed up with scientists at Birmingham University to show that invisibility cloaks could also be made from natural calcite crystals. In one demonstration, they showed how small objects, such as paperclips and pins, could be made invisible beneath a cloak built from two calcite prisms joined together to make a pyramid.

The latest cloak from Dr. Zhang uses normal glass to demonstrate how simple designs can still be effective.

Pendry, who has seen the latest study, said the work was "a genuine step forward," but added that there was more to cloaking devices than hiding domestic animals. "Behind the fun is the serious idea that people want to control light," he said. Using the same technology, for example, scientists are developing miniature satellite communications devices, he said.


[via Jennifer Kingson]

June 10, 2013 at 08:01 PM | Permalink | Comments (1) | TrackBack

How about a custom-made 24-carat gold iPad? Does that work for you?


It works for guests at the Burj Al Arab hotel in Dubai, where they'll soon start selling them to guests.

From the Los Angeles Times:


The sail-shaped Burj Al Arab hotel in Dubai, where rooms start at $1,525, is expanding the category of luxury accessories by providing all guests with a 24-karat gold iPad upon check-in. The hotel, part of the Jumeirah group of hotels and resorts, is often listed as the world's most luxurious hotel and already provides iMacs in each of its 202 suites.

The iPads were manufactured by Gold & Co. London and designed exclusively for Burj Al Arab. Each one is engraved with the hotel's logo as well as Jumeirah's motto, "Stay Different." Every tablet also comes loaded with interactive customer experience (ICE) software that enables guests to use the 24-karat gold iPad as a virtual concierge to access information and hotel services.

The iPads provided to guests are 16-gigabyte Wi-Fi iPad3s and for now run only the ICE program. The hotel is working on expanding customers' access to other iPad applications.

A 64-gigabyte version of the gold iPad3 is available to purchase at Burj Al Arab's Bespoke Boutique starting at $10,200.


Apply within.

[via The Economist]

June 10, 2013 at 04:01 PM | Permalink | Comments (2) | TrackBack

19 year-old Barbra Streisand's first appearance on TV (1961)


[via Flautist]

June 10, 2013 at 12:01 PM | Permalink | Comments (2) | TrackBack

20X Super-Long Range Telescopic Lens for iPhone 5 Photography


From the website:




This aluminum-cased telescopic lens with micromanual focus adjustment markedly enhances your iPhone camera's shooting ability, enabling you to get a very close view — without distortion — of objects TWENTY times further away than the distance your iPhone lens can pick up by itself.


It has a manual focus ring, a high quality tripod with 360° rotation, and can be adjusted to different heights.

This kit is the simplest and fastest way to turn your iPhone into a telescopic camera in seconds.

It can help you take high quality photos and video in a more convenient and easy way.

No batteries or wires are required.


$96.95 (iPhone 5 not included. You wouldn't think I'd have to note that but you'd be surprised how many people would ask me if I didn't specify that it isn't.).

June 10, 2013 at 08:01 AM | Permalink | Comments (0) | TrackBack

Self-healing concrete


It's here.

Excerpts from a March 5, 2013 Economist story follow.


It's useful stuff, concrete, but it does have drawbacks. One of the biggest is that it is not as weatherproof as the stone it often substitutes. Salt and ice routinely turn microscopic fractures in its fabric into gaping holes. These let water soak in. And that, in time, can cause the entire structure to fail. The upshot is that it concrete needs constant repair by teams of workmen assigned to fill in the newly formed gaps, which is tedious and expensive.... It would be better if the stuff could heal such damage by itself. And that, as he reports in Applied Materials & Interfaces, is exactly what Chan-Moon Chung of Yonsei University in South Korea hopes to get it to do.

Self-healing concrete is not a new idea. In 2009 a team at the Delft University of Technology in the Netherlands showed it is possible to mix special bacteria, which release crack-sealing chemicals, into concrete before it is poured. These bacteria do, indeed, keep the concrete healthy — but only while they are alive. Experience shows they last for about a year, so the biological route to self-healing concrete helps only a little.

Dr. Chung's approach, by contrast, is chemical. He and his colleagues knew from laboratory tests that when two substances called methacryloxypropyl-terminated polydimethylsiloxane and benzoin isobutyl ether are mixed in the presence of sunlight, they are transformed into a protective waterproof polymer that sticks readily to concrete. The challenge was to pack these chemicals up in a way that would keep them safe until they were needed, and then release them. The solution the team came up with was to put the healing balm inside tiny capsules made of urea and formaldehyde. These would screen the chemical mixture from sunlight and keep it safely stowed away. They would, however, be weak enough to rupture and release their contents when the concrete near them cracked.

To make these capsules, the team stirred together a solution of water, urea, ammonium chloride and a benzene derivative called resorcinol that encourages capsule formation. They then added methacryloxypropyl-terminated polydimethylsiloxane, benzoin isobutyl ether, and formaldehyde, and cooked the mixture for 4½ hours at 55°C. This process caused the urea and the formaldehyde to form, as desired, capsules containing the two concrete-healing chemicals.

To deploy his capsules, Dr. Chung mixed them into a liquid polymer, sprayed the mixture on to some concrete blocks, each weighing two-thirds of a kilo, and allowed the resulting film to solidify. He then cracked each block in turn, by applying pressure, and put the blocks out in the sun for four hours.

As he hoped, the cracks in the concrete propagated into the polymer film containing the capsules, and cracked some of them open too, releasing their contents. These then set, on exposure to the sun, into a waterproof layer — a fact he proved by immersing the blocks in water. After 24 hours immersion he weighed the blocks, to see how much water they had soaked up. On average, untreated concrete accumulated 11.3 grams of water. Concrete coated with capsule-free polymer took in 3.9 grams. But concrete covered with a polymer layer containing capsules absorbed just 0.4 grams. The cracks had, just as Dr. Chung hoped they would, healed themselves.

June 10, 2013 at 12:01 AM | Permalink | Comments (0) | TrackBack

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