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Quantum Time Reversal

DNA + quantum dot array, used as a quantum time reveral mirror
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It's already possible to create a time reversal mirror for sound (see a recent Scientific American). Throwing your voice for real, as it were: record the sound with a special microphone, reverse it and play it back, and the original sound reappears in its original location. It's also possible to attach the ends of several single strands of DNA to tiny bits of doped silicon - quantum dots that can immobilize single electrons, the state of which you can then easily play with. Mix a solution of dots with one sequence of DNA, with a solution appropriate cDNAqDots, and they form into a matrix. Play a "quantum event" that the dot matrix can pick up (and they're all quantum events, right?), record it, and reverse it.
dean, Feb 05 2000


ChachieWawa, Jul 03 2000

       (from the Wait-strike-that-reverse-it-thank-you department.)   

       I've heard of the acoustic version of this before, but I have to admit that I've never understood the practical use for it nor what [dean] means by "the original sound reappears in its original location." Does that mean that you can hear the sound again exactly as it could be heard the first time?   

       How does the quantum matrix play back the reversed event?
centauri, Jul 03 2000

       To the mirror question: "mirror" is a metaphor here. What is being "reflected" is a sequence of quantum states; in the acoustic version, what is being "reflected" is sound waves.   

       Speaking of the acoustic version: when the matrix plays the recorded signals in reverse, a microphone placed at the original origin of the sound picks up a pretty good image of the original signal, however weaker and somewhat lossy.   

       How would the quantum matrix replay the signal? That's a great question. Assuming some sort of addressable quantum dot matrix, I populate the available states sparsely. Then I conduct my event. As the event is occuring, I record the states of the electrons as they tunnel from state to state, or dot to dot. (Note: this DOES assume that I have selected an event that will cause electrons to change state!). I reverse this sequence to play the event back at the origin.
dean, Jul 06 2000

       Time reversal is an oxymoron.
RobEC, Jul 22 2000

       The generic case: "I have a device that can cause certain events that happened in the past to happen exactly as they happened in the past, in the past."   

       Explore this some more, I dare you. ;-)   

       Seriously, anything that helps us test our boundaries is welcomed. One day the stars will all burn out -- we'll need a new playground then.
Thing 1, Aug 13 2000

       a good practical use for this would be to put it ina CPU chip and use the "Mirror" to replay an event that caused a problem on the computer. this could lead to near bug-free software.
omega_scientist, Jan 19 2002

       So instead of a blue screen, we'd see a mirror?
thumbwax, Jan 19 2002

       I like to think i know a little physics, but I'm sadly going to have to add my vote to the *Huh?* camp. What on earth are you talking about? It sounds exciting and interesting, but...
sadie, Jul 08 2002

       His homepage is baloney.com; so what do you reckon?
angel, Jul 08 2002


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