Archive for October 3, 2011

Two Light Beams Make One Photonic Crystal?

October 3, 2011 Leave a comment

“Photonic crystals have been one of the hottest topics in optics in the last 10 years. This research is born out of a desire to have precise control over light—similar to the semiconductor industry’s control over electrons. The current favorite way to do this is to construct devices that have a refractive index that varies on the scale of the wavelength of light.

These metamaterials are made by combining two different materials in a very precise way, leading to all sorts of fabrication headaches. This may change in the near future because a pair of researchers have shown that you might be able to create temporary photonic crystals in a single material simply by shining a couple of light fields on it.

As a starting point, the researchers noted that the refractive index experienced by light changes dramatically when the material it’s passing through can absorb the light—that is, the light frequency is coincident with an atomic resonance. So, if you choose a light field that has a frequency that is slightly higher than an atomic resonance frequency, it will experience a lower refractive index.

On the other hand, if you choose light with a frequency slightly lower than the atomic resonance, it will experience a larger refractive index and some absorption. This doesn’t appear to help though—to get a useful difference between the two refractive indices, the light field has to be very nearly resonant with the atomic resonance. Over very short distances, the light is lost to absorption.

In a fit of creativity, and, seemingly, ignoring reality, the researchers asked themselves what would happen if a light field were simultaneously at a frequency that was both higher and lower than an atomic resonance? Of course, this can’t be the same atomic resonance, that would be too bizarre. Instead, the light is sandwiched between two neighboring resonances. One atomic resonance provides gain and the other absorption, with the two balancing exactly. Under these circumstances, the refractive index could be made to vary strongly.”

US Military Air Drones May Get Insect Hair Coats

October 3, 2011 Leave a comment

“For years, the military has turned to the birds and the bees for inspiration, churning out mechanical hummingbirds and remote-controlled insect cyborgs.

Now the Pentagon wants its mini-drones to have hairy wings and bug eyes, too. It’ll help the tiny machines spy on — and creep out — any enemies, military researchers promise…

Nature will be the engineers’ muse. A project to equip MAVs with hair-like sensors hopes to produce “the flight efficiency and agility of the hawkmoth,” the insect known for its hovering flight patterns.

To figure out how MAVs could keep flying smoothly even when the wind pipes up, another group is looking at how hair cells on bees’ bodies sense changes in air flow.”

Reusable Glass Nanoparticle Sponge Can Extract Toxins From Water

October 3, 2011 Leave a comment

A flexible web of glass nanoparticles makes up each piece of Osorb. When it comes in contact with pollutants, the web opens up to encapsulate them, causing the Osorb to swell. Ben Goldstein

“Chemist Paul Edmiston has plenty of data to prove how well Osorb, a glass substance, soaks up petroleum, solvents and other organic contaminants.

But he’s most convincing when he mixes motor oil with water, adds Osorb, filters off the swollen powder and drinks the remaining liquid. “It works like a nanomechanical sponge,” he says. “I’ve done trace analysis, and the water’s totally clean.”

A graduate student of Edmiston’s stumbled upon the material while experimenting with molecules for a bomb-detection device. After she added acetone to a beaker of silicas, they ballooned to eight times their normal size. She went straight to Edmiston, asking, “Did I mess up?”

Much to the contrary: The silicas, Edmiston realized, are hydrophobic, so they ignore water but grab both polar compounds (such as acetone) and nonpolar ones (such as octane) out of solution.

The contaminants can be released for disposal or recycling by squeezing the nanomechanical sponge—that is, by applying heat. The swellable glass can be reused more than 100 times.”

A Cellphone That Can Fully Charge in 10 Minutes?

October 3, 2011 Leave a comment

“NTT Docomo, one of Japan’s largest carriers, has developed a prototype battery that’s capable of achieving a complete charge in just ten minutes.

NTT reps weren’t willing to get into much detail about the new technology, which currently employs an external lithium-ion battery sleeve and is only designed to support NEC’s super-slim Medias Android (Japan only) smartphone.

They did let us take a look at the battery sleeve’s AC adapter, which supports output of up to 6.0 amps, but otherwise appeared to be fairly generic.

A pair of amp meters compared the power draw of a standard battery with that of the ultra high speed charger, which pulled 0.55 amps and 5.86 amps, respectively — at least according to the demo equipment on hand at NTT’s CEATEC booth.

The model we saw definitely looked very much like an early prototype at this point, and the carrier didn’t seem to have any idea of when it may begin to be implemented in handsets and other devices, only committing to a release “as soon as possible”.”

Chrome Wins the Latest Round of Browser Wars

October 3, 2011 Leave a comment

“Mozilla released the hotly-anticipated Firefox 7 two days ago. Does it deliver on the promise of speed and memory improvements? Does Firefox 7 have what it takes to dethrone current Web Browser Grand Prix champion, Google Chrome?

Analysis Table

Winner Strong Acceptable Weak
Performance Benchmarks
Startup Time Chrome Opera Firefox, Internet Explorer Safari
Page Load Time Chrome Safari Internet Explorer Firefox, Opera
JavaScript Chrome Firefox Internet Explorer, Opera Safari
DOM Opera Firefox Chrome, Safari Internet Explorer
CSS Chrome, Safari Internet Explorer, Opera Firefox
Flash Internet Explorer, Opera, Safari Chrome, Firefox
Java Firefox Chrome Internet Explorer, Opera, Safari
Silverlight Opera Chrome Firefox, Internet Explorer Safari
HTML5 Internet Explorer Firefox Chrome, Opera, Safari
HTML5 Hardware Acceleration Internet Explorer Firefox Chrome, Opera, Safari
WebGL Chrome Firefox Internet Explorer, Opera, Safari
Efficiency Benchmarks
Memory Usage: Light Internet Explorer Firefox, Safari Chrome, Opera
Memory Usage: Heavy Firefox Safari Opera Chrome, Internet Explorer
Memory Management Firefox Chrome, Internet Explorer Opera, Safari
Reliability Benchmarks
Proper Page Loads Opera Safari Chrome, Firefox Internet Explorer
Conformance Benchmarks
HTML5 Chrome Firefox, Opera Safari Internet Explorer
JavaScript Firefox Internet Explorer, Chrome Safari Opera
DOM All 5

The Pitfalls and Surprises of Amazon’s New Kindles

October 3, 2011 Leave a comment

“There’s been some unexpected discoveries in the details about Amazon’s four newest Kindles. I’ve tried to identify the 10 biggest surprises in the list below — starting with five bad surprises, and then five good.

1. There’s No 3G Web Browsing (except on Kindle Fire)
2. Power Adapters Not Included
3. One Miserable Keyboard
4. Your Personal Documents are now Stored at
5. Amazon Prime not Included

Now here’s five of the biggest good surprises about Amazon’s new upcoming Kindles…

1. Kindle Fire will have a NetFlix App!
2. The Kindle Fire Supports Flash
3. The Silk Browser is Incredibly Fast
4. One Special Offer Can Pay for the Cost of a Kindle
5. Amazon’s Selling Kindle Fire at a Loss”

Kinect To Estimate Human Age and Automate Parental Control?

October 3, 2011 Leave a comment

“Sorry, kid, but you’ve got the arms of a 12-year-old, and you’re not watching the Spice Channel tonight.

That’s the idea floated by Microsoft in a patent filing made public this week, proposing to use a 3D depth camera (such as the one in its Kinect sensor for Xbox 360) to digitally measure the proportions of a person’s body and estimate age based on the data, such as head width to shoulder width, and torso length to overall height.

The system could then automatically restrict access to television shows, movies and video games accordingly, using ratings for each type of content.

It might sound like science fiction, but it’s actually not a huge stretch, given the detailed skeletal tracking that Kinect already uses to let people control games.

As described in the patent application, the approach would give parents a new advantage over their tech-savvy kids, many of whom can easily circumvent existing parental controls.

But more than that, the technology could work dynamically — detecting when a kid enters the room, for example, and switching to more appropriate content.”