Monthly Archives: April 2012

An elementary quantum network of single atoms in optical cavities

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Quantum networks are distributed quantum many-body systems with tailored topology and controlled information exchange. They are the backbone of distributed quantum computing architectures and quantum communication. Here we present a prototype of such a quantum network based on single atoms embedded in optical cavities. We show that atom–cavity systems form universal nodes capable of sending, receiving, storing and releasing photonic quantum information. Quantum connectivity between nodes is achieved in the conceptually most fundamental way—by the coherent exchange of a single photon. We demonstrate the faithful transfer of an atomic quantum state and the creation of entanglement between two identical nodes in separate laboratories. The non-local state that is created is manipulated by local quantum bit (qubit) rotation. This efficient cavity-based approach to quantum networking is particularly promising because it offers a clear perspective for scalability, thus paving the way towards large-scale quantum networks and their applications.

via nature.com

Excellent

???Give me liberty or ??500??? is no rallying cry

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The canonical document of the Scottish independence movement is the Arbroath Declaration of 1320. ???It is in truth not for glory, nor riches, nor honours that we are fighting, but for freedom ??? for that alone, which no honest man gives up but with life itself.???

Nearly 700 years later, the Scottish Social Attitudes survey asked what respondents would think about independence for Scotland if it would make them ??500 a year better off. They favoured separation by 65 per cent to 24 per cent. If independence would make them ??500 a year worse off, however, it would be rejected by 66 per cent to 21 per cent. Yet ??500 is less than 2 per cent of average Scottish household income.

There were no similar polls in Ireland in 1920, or India in 1945, or America in 1773, but it is hard to imagine a similar result. ???Give me liberty or give me death,??? proclaimed Patrick Henry, arousing American colonists to rebellion with a cry reminiscent of the Declaration of Arbroath. ???Give me liberty or give me ??500??? lacks the same resonance.

The question cleverly illustrates that most Scots do not see the constitutional status of Scotland as integral to their identity or self-worth. That is what differentiates the Scottish debate on independence from that which convulsed Ireland or India, or divided America, and trivialises it.

via johnkay.com

Kids Online: the Risks and the Realities

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KNOW THE DIFFERENCE BETWEEN RISK AND HARM. It might seem like just a semantic distinction, but recognizing the difference between risk and harm is important. Livingston contends that while the risk is real when it comes to being exposed to inappropriate material online, the probability of harm is low. ???The risk remains but the parents??? task is not to eliminate risk but do everything they can to make sure the low probability harm doesn???t happen to their child,??? she says. ???Children have to encounter risks because it???s how they live and learn. It???s how they go out into the world and become resilient.

via blogs.kqed.org

What was it about Instagram that made it worth a $1B acquisition by Facebook?

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Here’s another angle on a set of already very good answers: the most obvious value of Facebook as a service to users is for one-to-many communications of “present tense” thoughts and activity. Photos are already a huge part of that experience, as I believe that Facebook is the single largest photo sharing service on the web.

The collection of all of those “present tense” things + the passage of time means that Facebook also is a massive repository of “past tense” things. This reality is reflected in the recent Facebook Timeline redesign/launch.

Facebook is to the 21st Century what Kodak was to the 20th Century. They catalog what you thought, who you were with, and – most pertinently to this question – what you saw. They’re in the business of capturing and sharing memories.

The value that Instagram provides to users is that it makes memories more interesting. That’s a pretty solid alignment with what Facebook is all about these days.

via quora.com

when I post images from my cellphone it’s emailed (to a distribution list that includes the Twitpic & Facebook posting addresses) and its not trivial.

This answer reminded me that if you make something even a little easier, there may be surprising suppressed demand for the facility.

I actually post pictures in preference to status updates, for me, they are easier. Going by the number of other spontaneous “Kodak moments” I see (very few), that’s not the case for many.

The “Insta” in Instagram.

Schneier on Security: Teenagers and Privacy

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Rather than fearing the unknown stranger, young adults are more wary of the “known other” — parents, school teachers, classmates, etc. — for fear of “the potential for the known others to share embarrassing information about them”; 83 percent of the sample group cited at least one known other they wanted to maintain their privacy from; 71 percent cited at least one known adult. Strikingly, seven out of the 10 participants who reported an incident when their privacy was breached said it was “perpetrated by known others.

via schneier.com

The kids are alright.

Bye Bye BlackBerry. How Long Will Apple Last?

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Consider some of the pessimistic predictions that preceded Apple???s entry into the smartphone business:

  • In December 2006, Palm CEO Ed Colligan summarily dismissed the idea that a traditional personal computing company could compete in the smartphone business. ???We???ve learned and struggled for a few years here figuring out how to make a decent phone,??? he said. ???PC guys are not going to just figure this out. They???re not going to just walk in.???
  • In January 2007, Microsoft CEO Steve Ballmer laughed off the prospect of an expensive smartphone without a keyboard having a chance in the marketplace as follows: ???Five hundred dollars? Fully subsidized? With a plan? I said that???s the most expensive phone in the world and it doesn???t appeal to business customers because it doesn???t have a keyboard, which makes it not a very good e-mail machine.???
  • In March 2007, computing industry pundit John C. Dvorak argued that ???Apple should pull the plug on the iPhone??? since ???There is no likelihood that Apple can be successful in a business this competitive.??? Dvorak believed the mobile handset business was already locked up by the era???s major players. ???This is not an emerging business. In fact it???s gone so far that it???s in the process of consolidation with probably two players dominating everything, Nokia Corp. and Motorola Inc.???

This serves as a classic example of those with a static snapshot mentality disregarding the potential for new entry and technological disruption.

via forbes.com

Hindsight perhaps, but there was huge suppressed customer satisfaction demand, functionality of networks and handsets was exploding (still is), replacement cycles were short, subsidy was available, proprietary systems were past their use by, open source credibility was high. Excellent entr??es for Apple customer marketing and Android open model with Google behind it.