Thursday, November 16, 2006

Looking for the Future in the Past ...

Going for a blast into the real past
If the experiment works, a signal could be received before it's sent


If his experiment with splitting photons actually works, says University of Washington physicist John Cramer, the next step will be to test for quantum "retrocausality."

That's science talk for saying he hopes to find evidence of a photon going backward in time.

"It doesn't seem like it should work, but on the other hand, I can't see what would prevent it from working," Cramer said. "If it does work, you could receive the signal 50 microseconds before you send it."

Uh, huh ... what? Wait a minute. What is that supposed to mean?

Roughly put, Cramer is talking about the subatomic equivalent of arriving at the train station before you've left home, of winning the lottery before you've bought the ticket, of graduating from high school before you've been born -- or something like that.

"It probably won't work," he said again carefully, peering through his large glasses as if to determine his audience's mental capacity for digesting the information. Cramer, an accomplished experimental physicist who also writes science fiction, knows this sounds more like a made-for-TV script on the Sci Fi Channel than serious scientific research.

"But even if it doesn't work, we should be able to learn something new about quantum mechanics by trying it," he said. What he and UW colleague Warren Nagourney plan to try soon is an experiment aimed at resolving some niggling contradictions in one of the most fundamental branches of physics known as quantum mechanics, or quantum theory.

"To be honest, I only have a faint understanding of what John's talking about," Nagourney said, smiling. Though claiming to be "just a technician" on this project, Cramer's technician partner previously assisted with the research of Hans Dehmelt, the UW scientist who won the 1989 Nobel Prize in physics.

Quantum theory describes the behavior of matter and energy at the atomic and subatomic levels, a level of reality where most of the more familiar Newtonian laws of physics (why planets spin, airplanes fly and baseballs curve) no longer apply.

The problem with quantum theory, put simply, is that it's really weird. Findings at the quantum level don't fit well with either Newton's or Einstein's view of reality at the macro level, and attempts to explain quantum behavior often appear inherently contradictory.

"There's a whole zoo of quantum paradoxes out there," Cramer said. "That's part of the reason Einstein hated quantum mechanics."

One of the paradoxes of interest to Cramer is known as "entanglement." It's also known as the Einstein-Podolsky-Rosen paradox, named for the three scientists who described its apparent absurdity as an argument against quantum theory.

Basically, the idea is that interacting, or entangled, subatomic particles such as two photons -- the fundamental units of light -- can affect each other no matter how far apart in time or space.

"If you do a measurement on one, it has an immediate effect on the other even if they are separated by light years across the universe," Cramer said. If one of the entangled photon's trajectory tilts up, the other one, no matter how distant, will tilt down to compensate.

Einstein ridiculed the idea as "spooky action at a distance." Quantum mechanics must be wrong, the father of relativity contended, because that behavior requires some kind of "signal" passing between the two particles at a speed faster than light.

This is where going backward in time comes in. If the entanglement happens (and the experimental evidence, at this point, says it does), Cramer contends it implies retrocausality. Instead of cause and effect, the effect comes before the cause. The simplest, least paradoxical explanation for that, he says, is that some kind of signal or communication occurs between the two photons in reverse time.

It's all incredibly counterintuitive, Cramer acknowledged.

But standard theoretical attempts to deal with entanglement have become a bit tortured, he said. As evidence supporting quantum theory has grown, theorists have tried to reconcile the paradox of entanglement by basically explaining away the possibility of the two particles somehow communicating.

"The general conclusion has been that there isn't really any signaling between the two locations," he said. But Cramer said there is reason to question the common wisdom.

Cramer's approach to explaining entanglement is based on the proposition that particles at the quantum level can interact using signals that go both forward and backward in time. It has not been the most widely accepted idea.

But new findings, especially a recent "entangled photon" experiment at the University of Innsbruck, Austria, testing conservation of momentum in photons, has provided Cramer with what he believes is reason for challenging what had been an untestable, standard assumption of quantum mechanics.

The UW physicists plan to modify the Austrians' experiment to see if they can demonstrate communication between two entangled photons. At the quantum level, photons exist as both particles and waves. Which form they take is determined by how they are measured.

"We're going to shoot an ultraviolet laser into a (special type of) crystal, and out will come two lower-energy photons that are entangled," Cramer said.

For the first phase of the experiment, to be started early next year , they will look for evidence of signaling between the entangled photons. Finding that would, by itself, represent a stunning achievement. Ultimately, the UW scientists hope to test for retrocausality -- evidence of a signal sent between photons backward in time.

In that final phase, one of the entangled photons will be sent through a slit screen to a detector that will register it as either a particle or a wave -- because, again, the photon can be either. The other photon will be sent toward two 10-kilometer (6.2-mile) spools of fiber optic cables before emerging to hit a movable detector, he said.

Adjusting the position of the detector that captures the second photon (the one sent through the cables) determines whether it is detected as a particle or a wave.

The trip through the optical cables also will delay the second photon relative to the first one by 50 microseconds, Cramer said.

Here's where it gets weird.

Because these two photons are entangled, the act of detecting the second as either a wave or a particle should simultaneously force the other photon to also change into either a wave or a particle. But that would have to happen to the first photon before it hits its detector -- which it will hit 50 microseconds before the second photon is detected.

That is what quantum mechanics predicts should happen. And if it does, signaling would have gone backward in time relative to the first photon.

"There's no obvious explanation why this won't work," Cramer said. But he didn't consider testing this experimentally, he said, until he proposed it in June at a meeting sponsored by the American Association for the Advancement of Science.

"I thought it would get shot down, but people got excited by it," Cramer said. "People tell me it can't work, but nobody seems to be able to explain why it won't."

If the UW experiment succeeds at demonstrating faster-than-light communication and reverse causation, the implications are enormous. Besides altering our concept of time, the signaling finding alone would almost certainly revolutionize communication technologies.

"A NASA engineer on Earth could put on goggles and steer a Mars rover in real time," said Cramer, offering one example.

Even if this does fail miserably, providing no insights, Cramer said the experience could still be valuable. As the author of two science-fiction novels, "Twistor" and "Einstein's Bridge," and as a columnist for the sci-fi magazine Analog, the UW physicist enjoys sharing his speculations about the nature of reality with the public.

"I want people to know what it's like to do science, what makes it so exciting," he said. "If this experiment fails in reality, maybe I'll write a book in which it works."

Tuesday, November 14, 2006

Intel Announces Web 2.0 Suite

Intel creates integrated offering of Internet collaboration technologies.
November 8, 2006

Intel has partnered with a group of Web 2.0 companies to form a suite of Web software that will help small and medium businesses share information, the company announced Tuesday.

Intel and its partners made the announcement at the annual Web 2.0 conference in San Francisco, which brings together all the players in the movement popularly known as “Web 2.0.” This is the second wave in the Internet phenomenon which allow consumers to create their own dynamic web pages, collaborate with others, and share photos and videos.

Known as Suite Two, it is a combination of interconnected services from different Web 2.0 companies that aims to improve productivity within small and medium-sized businesses. Intel wants to bring consumer technologies to businesses, the company said.

“The idea is to develop a suite which includes capabilities like blogging, wikis, and RSS,” said Lisa Lampert, managing director of Intel Capital’s Software and Solutions Group. Intel Capital is the venture arm of the world’s largest chipmaker and has investments in several companies that are enabling the Web 2.0 phenomenon such as SixApart, SpikeSource, and Zend Technologies.

SixApart and SpikeSource will form a large part of the Suite Two offering, other than SocialText, NewsGator, and SimpleFeed.

SpikeSource will provide the integration platform for Suite Two which will bring together infrastructure and applications together. SixApart is a provider of blogging software and Socialtext sells software that helps companies collaborate through wikis—or private web pages that are editable instead of sending emails and attachments back and forth.

NewsGator and SimpleFeed will be providing RSS capabilities—for Really Simple Syndication—to access external news and industry information.

This suite will operate on PC-based hardware and all the services will be integrated with a single sign-on and a rich user interface seen on most consumer web sites. The suite will be released in early 2007 and available through Intel’s global channel of OEMs, distributors, and resellers. It will run on Red Hat Enterprise Linux, SuSe Linux, and Microsoft Windows operating systems, the company said.

Intel is investing in these companies and solutions to ensure that these next-generation technologies work well on Intel-based hardware, Ms. Lampert said.

Intel and its partners are banking on the fact that small and medium businesses do not have IT departments and need external, plug-and-play solutions to run their businesses while also adopting new technologies, said SpikeSource CEO Kim Polese.

The price structure is relatively lower at $175 to $200 per user per year to drive adoption within SMBs. Socialtext CEO Ross Mayfield said these technologies are being used in large corporations and SMBs should benefit from them, too.

“You have projections such as 50 percent of companies will be using wikis by 2008 and 80 percent of them will be using blogs,” Mr. Mayfield said. “This is particularly driven by how popular Web 2.0 tools are on the consumer side; you are seeing some grassroots demand and for organizations [like ours] to fulfill the demand.”

Intel’s Ms. Lampert said the above-mentioned features will be available in the first release and forthcoming releases will add more advanced features such as social networking, podcasting, and mobility. Intel is working with leaders in each of these new categories to partner for the Suite Two offering, she said