{"id":6886,"date":"2011-06-03T13:00:49","date_gmt":"2011-06-03T20:00:49","guid":{"rendered":"http:\/\/blogs.discovermagazine.com\/cosmicvariance\/?p=6886"},"modified":"2011-06-03T13:00:49","modified_gmt":"2011-06-03T20:00:49","slug":"dna-takes-square-roots","status":"publish","type":"post","link":"https:\/\/preposterousuniverse.com\/blog\/2011\/06\/03\/dna-takes-square-roots\/","title":{"rendered":"DNA Takes Square Roots"},"content":{"rendered":"

Around these parts we’ve been known to discuss whether it makes any sense to say that the universe is a computer<\/a>. There’s little doubt, of course, that parts<\/em> of the universe are computer-like. And in case you are wondering, you can now officially remove DNA from your personal list of “things I suspect are not computers.”<\/p>\n

Caltech researchers Lulu Qian and Erik Winfree<\/a> have managed to coax 130 strands of DNA into performing what is unquestionably a calculation: taking the square root of a number. (Ars Technica post<\/a>; Science<\/em> paper<\/a> behind paywall; open-access background paper<\/a>.) Not a big number: we’re talking about four-digit binary numbers, so 15 at the biggest. And not very efficiently: with prodding, the calculation took eight hours. Moore’s Law isn’t really in danger here.<\/p>\n

Still, pretty cool stuff. Mostly it’s interesting because it seems scalable: the authors claim that this kind of circuit architecture could be made much larger. It’s not the first biochemical circuit; RNA and bacterial colonies have been made into logic gates. But it’s the first to do something as elaborate as taking a square root.<\/p>\n

Best of all, the authors decided to illustrate their method for a wide audience by means of a … whimsical YouTube video! Let’s hope this idea catches on.<\/p>\n

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The seesaw magic book: the computational power of DNA molecules<\/div><\/div>
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