<i xmlns="http://purl.org/rss/1.0/">Star Wars</i>-style holograms: a new hope? - Nature.com

Novel plastic could enable real-time 3D holographic projections.

Princess Leia could soon be beamed into a room near you.LUCASFILM/20TH CENTURY FOX/THE KOBAL COLLECTION

The fuzzy three-dimensional (3D) image of Princess Leia calling for help in the 1977 film Star Wars demonstrates an effect that researchers have long been trying to achieve: holograms that move in real time. Now, a material that can store shifting holographic data moves the fantasy into the realms of reality. The substance could have future applications in medicine and manufacturing, as well as in the entertainment industry.

"From day one, I thought about the hologram of Princess Leia and whether it can be brought out of science fiction," says Nasser Peyghambarian, an optical scientist at the University of Arizona in Tucson, who has been trying for several years to develop holographic projections that move in real time.

The challenge was to find a rewritable material that could store data encoding successive holographic images. Now Peyghambarian and his colleagues have developed a material that can record and display 3D images that refresh every two seconds. The research is published in Nature this week 1.

The team's system captures 3D information by filming an object from multiple angles, using 16 cameras that each take an image of the object every second. The 16 views are processed into holographic pixel data by a computer, which sends a signal to two pulsed laser beams that then write the data into the recording material.

During the writing process, the two beams combine to create an interference pattern of light and dark patches in the recording material. Firing another light at the pattern reconstructs the 3D image.

In a static hologram, the physical properties of the recording material are permanently changed by this interference pattern, so the image can never be refreshed. In contrast, Peyghambarian's team has developed a rewritable recording material from a combination of plastic polymers, dubbed PATPD/CAAN. When the laser beams hit the copolymer, they cause electrons and other charge carriers within it to drift and gather in areas corresponding to dark and light regions of the interference pattern, creating a temporary recording. The stored image can then be overwritten by the next round of image data to be displayed.

“Creating a dynamic hologram of the size and resolution of Princess Leia is a reality.”

Nasser Peyghambarian
University of Arizona, Tucson

In 2008, the team used a similar material to build a 4-inch display that took about 4 minutes to overwrite 2. Now, they have modified the mix of polymers to develop a 17-inch display that refreshes more than a hundred times faster, generating an image that changes in almost "real time", says Peyghambarian.

Although 3D televisions are already on the market, these are filmed from just two perspectives. So they give a sense of depth, but "you cannot walk around an image of a person and see the back of his head", says Peyghambarian.

He hopes that, along with revolutionizing entertainment, the hologram technique will one day enable surgeons to remotely view live 3D images of operations and give advice. It might also find uses in manufacturing, allowing engineers to visualize and modify 3D models in real time.

However, Rob Eason, an optical physicist at the University of Southampton, UK, points out that the holographic images are still relatively slow and small, and questions whether the technique significantly improves on other recent advances in 3D displays. In 2009, for example, Sony unveiled a prototype called RayModeller. It projects a moving 3D image within a cylindrical tube, allowing the viewer to walk all the way around it and see different perspectives.

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Peyghambarian counters that a scaled-up holographic system would provide "superb resolution. We can already make a holographic pixel of 400 micrometres — better than a high-definition television."

He adds that it should be easy in principle to record holographic movies, so they can be played back later. The team is now working to speed up the refresh rate to match the 30 frames per second needed for movies, and to reduce the amount of power needed to read and write images.

Peyghambarian believes that some version of the system could be in homes within seven to ten years: "We have shown that creating a dynamic hologram of the size and resolution of Princess Leia is a reality." Now he just needs to build an R2-D2 to play it on. 

Blanche, P.-A. et al. Nature 468, 80-83 (2010).Tay, S. et al. Nature 451, 694-698 (2008).If you find something abusive or inappropriate or which does not otherwise comply with our Terms or Community Guidelines, please select the relevant 'Report this comment' link.

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Election Day could bring historic split: Democrats lose House, keep Senate - Washington Post

The question around Washington today is not whether Nov. 2 will be a difficult day for the Democrats who control Congress, but rather how bad it will be.

Increasingly, it looks like the answer depends on which chamber of Congress you're following.

The nonpartisan Cook Political Report now estimates that more than 90 Democratic House seats are potentially in play; on the Republican side of the aisle, it estimates that only nine appear in jeopardy. As a result, most leading forecasters say it is more likely that Republicans will win the 39 House seats they need to take control.

On the Senate side, however, the battle has narrowed to a handful of true nail-biters in Nevada, Pennsylvania, Illinois and Colorado - all of which are likely to stay close to the end.

It would take a sweep of nearly all of them, improbable but not impossible, for the Republicans to pick up the 10 seats they need to gain control of the chamber. At this point, it's possible that Democrats will end up losing only three or four seats, and they will count that as a good night.

If these trends hold - if the Republicans do gain the House without also taking control of the Senate - that would represent a historic anomaly: Not since the election of 1930 has the House changed hands without the Senate following suit.

Two national party officials, Republican National Committee Chairman Michael S. Steele and Democratic National Committee Chairman Timothy M. Kaine, gave very different predictions Sunday of what would happen on Election Day.

Steele said on NBC's "Meet the Press" that an unprecedented GOP wave would win control of both chambers as well as state legislatures, in a broad condemnation of President Obama and Democratic policies.

"The voters are tired of the fact that the federal government has not listened to them over the past two years, has moved in its own direction, at its own rhythm, and they want to pull back on that," Steele said.

Kaine, speaking on ABC's "This Week" pointed to strengthening poll numbers for his party's candidates as a sign that the Democratic base was getting energized.

"Four or five months ago, the Republicans thought they had a great chance at taking both houses," Kaine said. "For a variety of reasons, the Senate has gotten much more difficult for them. And again, we're seeing this week strong moves in polling for our Senate candidates" in several states.

Reflecting that potential trend, a Los Angeles Times/USC poll released Sunday found Democratic Sen. Barbara Boxer (Calif.) eight points ahead of Republican challenger Carly Fiorina, and a Denver Post/SurveyUSA poll found Democratic Sen. Michael Bennet (Colo.) tied with Republican challenger Ken Buck, whom he had trailed for months.

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Apple to triple iTunes music previews from 30 to 90 seconds - IntoMobile

A leaked memo from Apple to the music labels suggests Apple is increasing the length of music previews on iTunes from 30 seconds to 90 seconds. The change would only affect music files that are longer than 2 minutes and 30 seconds. Tracks shorter than this arbitrary limit will keep the 30 seconds preview. Previously rumored to be announced at Apple’s Fall event, this feature was reportedly delayed because of licensing problems. This latest leak implies that these licensing issues have been resolved and the feature is ready to roll out.

While this change may seem to trivial to users, it reflects the ongoing battle between Apple and the music industry. The struggle over DRM, pricing, previews, and more started when Apple launched iTunes  Music Store back in 2003. Steve Jobs has pushed the music industry to offer music tracks for 99-cents and then to offer tracks without DRM. This music preview is the next skirmish, but a bigger battle looms in the future.

The next battleground will be the cloud as Apple is rumored to be turning its LaLa acquisition into an iTunes-in-the-cloud service. In this scenario, iPhone, iPod touch, and iPad owners would be able to store their media in the cloud and use iTunes to stream their favorite music or videos while on the go. A subscription-based iTunes service is also reportedly close to launch. Steve Jobs has been able to successfully negotiate with the recording industry thus far, let’s hope they can pull off another coup d’etat and move our iDevices away from the desktop and into the cloud.

[Via MacRumors]

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