X-Message-Number: 21058 From: Date: Wed, 5 Feb 2003 05:18:27 EST Subject: Data flow --part1_103.261ad739.2b723ef3_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit "Every complex, difficult problem has a simple, easy solution, which is wrong." Extracting informations from a partially autolysed brain is a difficult complex problem. I have suggested two solutions: An intensity interferometer using quasi-particles such phonons and a quantum non-demolition x-ray interferometer. My estimates are that the first would need some months to scan a brain at the small molecular level. The QND interferometer would do the job in some seconds. So at first sight, the second seems far better. To be sure, the first would be simpler to build and a part of its technology would be requested for the second... There I would see them on another angle: The data flow and processing. Assume a brain volume is 1,500 cm^3 or in round value: 1000 cm^3. If there is one molecule for each nanometer, then the scan must looks at: 10^24 places. The data for such a mesh could be 100 bytes, so the total data would be: 10^26 b. The slow intensity interferometer taking 4 months for a scan (10 millions seconds) would sustain a data flow of 10^20 bit/second. Even with a compression factor near 100, this would let one billion gigabits/s. Assume we can handle on an electronics circuit a 10 terahertz waveband or nearly 10^13 bits/s, we are short by a factor of 100,000. A solution would be to use an optical fiber technology. A cable can contain up to 1,000 fibers, this is what can be found in astronomical fiber feed spectrographs. Each fiber can have up to one hundred propagation mode, each is, in fact an independent light beam. For each mode in each fiber there can be 100 carrier frequencies. So in the end, an optical system could boost the electronics modulation capacity by up to ten millions. All data could be routed without compression. Another option would be to limit the modulation frequency to 100 GHz. This is 10 - 20 times what can be found today and may be the technology on the market ten years from now. The intensity Interferometer data flow seems so a manageable problem. The QND interferometer on the other hand would have a data flow one million time larger. Even with 1,000 propagation modes in 10,000 optical fibers, the electronics modulator can't work under 10 THz with the maximum data compression. the carrier wave would have a frequency in the 100 THz range. Clearly, a mere extension of current electronics devices can't cope with that. What are the possibilities? Spintronics? Collective electron gas waves? Free electron lasers? Whatever the selected solution, it will take time to be implemented. These requirements are so specific to a brain reader than we can't simply wait for the general progress to produce it. We have to create that technology or it will never materialize. This is not a philosophical question: The answer will define where the money will go 2 or 3 years from now. Yvan Bozzonetti. --part1_103.261ad739.2b723ef3_boundary Content-Type: text/html; charset="US-ASCII" [ AUTOMATICALLY SKIPPING HTML ENCODING! ] Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=21058