Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!wuarchive!mit-eddie!rutgers!aramis.rutgers.edu!athos.rutgers.edu!nanotech From: eachus@linus.mitre.org (Robert I. Eachus) Newsgroups: sci.nanotech Subject: Re: Down and Out in Nanoland Message-ID: Date: 12 Jan 91 05:26:56 GMT Sender: nanotech@athos.rutgers.edu Organization: The Mitre Corporation, Bedford, MA Lines: 66 Approved: nanotech@aramis.rutgers.edu I'm not sure that I agree with your (JoSH's) estimate of the number of MIPS required for an uploaded persona to function. As you can see below, I don't disagree with your basic statement AI before uploading, but I do disagree with when. There are four areas where I would like to dispute your numbers: First, 1 MIPS for a single synapse, 1000 synapses per neuron implies that the only useful way to simulate a neuron is as a collection of synapses. My feeling is that the proper approach might be to simulate neurons instead, and my guess is that a "real-time" neuron simulation can be done for under 100 MIPS. Next, under most circumstances a lot of areas of the brain are dormant. Simulation of neurons with no input will require no computational effort. This should account for another factor of ten. Another factor of ten or 100, or more, comes simply from the fact that you may be willing to upload to a "slow" machine if the alternative is death. One "supercomputer" system may be needed to do the initial upload, but the software can then be transferred to a slower machine. As the hardware available gets better you can migrate the software. This really means that the limit on when uploading becomes possible is primarily a storage limit. (Hmmm. Say each neuron state would take one the order of 10Kbytes to represent, remember that packing can be very efficient, so we need order of 10**14 bytes of memory. Current systems are on the order of 10 Meg, and actually growing slightly faster than 1000x per decade, but lets use that. No uploading before say, 2015.) Last but not least, even if we buy your estimate of the computational effort involved, the correct measure for 1990 is the number of parallel processing MIPS available, since this is an inherently parallel problem. 1990 ~= 1000 MIPS. This also pulls in the uploading date to about 2015. So all in all I put the uploading date about 15 years earlier, and the AI date about the five to 10 years earlier, in about 2000-2005, from the parallel processing difference. This may seem highly optimistic, but there was an article many years ago in Analog entitled "Science Fiction is too Conservative" by G. Harry Stine. It showed that even most of the wildest extrapolations in science fiction drastically underestimated the rate of change in technology. In this group anyway, we are at least using exponential estimates for performance growth, but as I remember the article, even e**x, as above, is a little pessimistic for most observed curves. -- Robert I. Eachus When the dictators are ready to make war upon us, they will not wait for an act of war on our part." - Franklin D. Roosevelt ["Lots of my friends are running on eta-op processors, but I wouldn't let my sister upload into one!" I can't really argue with your numbers except to say that I used a lot of "let's include this to be on the safe side" and you did the opposite. Just to bring the point back to where we started, 1000 MIPS machines cost millions today, and if we stay on that trendline, we don't have to worry about a lot of destitute people buying multi-million-dollar machines to upload copies of themselves onto. Outside of that, I agree. --JoSH]