X-Message-Number: 21270 From: Date: Tue, 25 Feb 2003 13:02:02 EST Subject: Entangled interferometers --part1_9.b3374ae.2b8d099a_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit For archival purpose, I have sent to cryonet a number of messages about brain readers. I have identified 3 technologies: -Nuclear resonance imaging with laser polarized helium 3 under high pressure and low temperature. This system would be the simplest to build, but couln'd see "digested" neural buttons. -Intensity interferometer using exciton particles such phonons, able to see anything, down to atomic level. Drawback: It is slow. -X-ray interferometer using quantum non demolition: Powerful and fast, but long and hard to build. There I would point out the possibility to build an intermediate interferometer. It could use entangled light or radio wave photons to get the necessary definition, down to atomic level. The system would look as a sea urchin, with interferometer harms in all directions. It could test the data processing of an X-ray machine. It would be far simpler to build because everything would work in the optical or radio spectrum. So, most technologies would be off the shelf here. The drawback is that using atomic, not nuclear light sources, the coherence length would be small and that is a strong limit on the QND effect. If we have a laser light with a coherence length in the 100 m range and the travel in the interferometer is 10 m, that allows at most 10 travel. In rough numbers, the absorbed energy would be 1/10 th of what would give direct atomic imaging. Given in one dose, this would be sufficient to vaporize the sample. Extended on some hours with active cooling it could be used on fossils. On a frozen brain, the radiation damages would be too large. The X-ray QND system would be one million times less destructive. Nevertheless, I think this system would be interesting as an intermediate step and a tool for non living objects. The same technology with radio wave would produce a bigger system, may be a 100 meters in diameter "sea urchin." To get atom scale definition, more photons would have to be entangled and the final energy would remains the same, so the radiation effects are similar. The difference is that a radio wave can be produced with 10,000 miles coherence length, only 1/10th of the nuclear X-rays. So, a QND system would be only 10 times more noxious than the X-ray machine. One big advantage for brain reader is that radio wave can pass throughout the bone head without tinkering with probability distribution in each photon to get very special unbunching. There is a final possibility: Intensity Interferometers use correlation between photons with very different arrival time. Could that be adapted to the QND system so that high quantum non demolition factor could be used with limited first order coherence length? I know of no studies mixing intensity interferometer and QND in entangled states. It seems that even basic theoretical works have to be done in that domain. If it worked, we could jump in few years from an intensity interferometer to a radio-wave QND machine as powerful as the X-ray machine. A fast brain reader could be only 15 years from now. That possibility tell us that we must try something in that domain, but we keep in mind that this machine "seems" possible, without more precision. At this stage, it is good sci-fi, nothing more. Yvan Bozzonetti. --part1_9.b3374ae.2b8d099a_boundary Content-Type: text/html; charset="US-ASCII" [ AUTOMATICALLY SKIPPING HTML ENCODING! ] Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=21270