bloomber@marlin.UUCP (01/24/85)
I have been reading some articles about alternate computer architectures
and am curious about the following:
*** Optical Computers ***
1. What work has been done in actually building an optical computer??
(That is a computer whose logic states are determined by
properties of light)
2. What are the advantages of such a computer?? (My understanding is
that processing speed is MUCH quicker than conventional architectures.
How much faster?? Why??) Also, the amount of memory in a "crystal" drive
is much greater than a normal disk drive (say, of the same volume).
3. What would be a rough estimate of the costs of producing such a
computer on a commercial basis?? Does this technology have the
potential to be mass reproducable.
4. My understanding is that an optical computer would have multistate
logic. What is the connection (if any) between fuzzy logic and
multistate logic?? Would such logic be more condusive to AI
applications??
*** Molecular and Chemical Computers ***
1. I read some eons ago about efforts to use organic molecules in a
supercooled liquid as a memory device. Whatever happened to that
line of research??
2. Since human brain activity is electrical and chemical in nature,
what efforts has been made to simulate the METHODOLOGY of human
thought on a computer? For example, has any research been done
to find the electrical and chemical sequence that occurs when
someone is typing a line of text (like what I just did)??
*** Logical Inference Machines ***
My understanding is that a Logical Inference Machine has the
fundamental unit of processing a "Logical Inference". What
exactly is a "logical inference" in this context? Are these
machines non-Von's or are they two separate things??
I realize these questions are quite general in scope. My knowledge
of computer architecture is quite limited. However, I would like
to learn more and appreciate any responses the net community
might offer.
Mike
--
Real Life: Michael Bloomberg
MILNET: bloomber@nosc
UUCP: [ihnp4,akgua,decvax,dcdwest,ucbvax]!sdcsvax!noscvax!bloomberroy@phri.UUCP (Roy Smith) (01/28/85)
> 1. What work has been done in actually building an optical computer?? > (That is a computer whose logic states are determined by > properties of light) > > Michael Bloomberg > [ihnp4,akgua,decvax,dcdwest,ucbvax]!sdcsvax!noscvax!bloomber I was at the "Computers in Science" conference held Oct 29 -- Nov 1, 1984 in Washington and heard a distincly facinating talk about the optical and electronic properties of polymeric solids (specificly substituted poly- acetlyenes). Most of it went right over my head (I suspect it would have been better recieved by an audience of semiconductor physicists), but the gist of it was that these solids can be made to change their conductivity by a factor of 10**12 (!!) by illuminating them with the proper wavelength of light. This is all real exploratory basic research, but it seems plausable that these materials could be fabricated monolithicly. I would have posted the abstract, but I suspect that would violate copyrights. The only address I have for the author is: Sukant Tripathy, GTE Laboratories, Inc. Waltham, Ma. If you have any interest, I would strongly suggest digging up the literature. -- allegra!vax135!timeinc\ cmcl2!rocky2!cubsvax>!phri!roy (Roy Smith) ihnp4!timeinc/
vince@fluke.UUCP (Craig V. Johnson) (01/29/85)
> 2. Since human brain activity is electrical and chemical in nature, > what efforts has been made to simulate the METHODOLOGY of human > thought on a computer? For example, has any research been done > to find the electrical and chemical sequence that occurs when > someone is typing a line of text (like what I just did)?? > > Real Life: Michael Bloomberg > MILNET: bloomber@nosc > UUCP: [ihnp4,akgua,decvax,dcdwest,ucbvax]!sdcsvax!noscvax!bloomber Mike, would you like to donate your brain so we could poke and fidgit with it while you type? Sure research has been done, but it is quite slow for some rather obvious reasons. Craig Johnson uw-beaver! \ John Fluke Mfg. Co., Inc. decvax!microsof! \ Everett, Washington ucbvax!lbl-csam! > fluke!vince allegra! / ssc-vax! /
eugene@ames.UUCP (Eugene Miya) (01/29/85)
> > I have been reading some articles about alternate computer architectures > and am curious about the following: > > *** Optical Computers *** > > 1. What work has been done in actually building an optical computer?? > (That is a computer whose logic states are determined by > properties of light) There is a company trying to build a hybrid electronic/optical [Guiltech]. See mention of other places to look in the next paragraph. > > 2. What are the advantages of such a computer?? (My understanding is > that processing speed is MUCH quicker than conventional architectures. > How much faster?? Why??) Also, the amount of memory in a "crystal" drive > is much greater than a normal disk drive (say, of the same volume). The way it was explained to me by vax135!alan, is infinite parallelism. The suggested reading material should be Proc. of the IEEE, July 1984, survey on optical computing. Photons have the advantage of not interacting with one another (also a disadvantage since this is how electrons have an advantage with transistors). Alan Huang at Bell made me a convert on this. You can have many beams (slide projectors) thru the same space. > > *** Molecular and Chemical Computers *** > > 1. I read some eons ago about efforts to use organic molecules in a > supercooled liquid as a memory device. Whatever happened to that > line of research?? > > 2. Since human brain activity is electrical and chemical in nature, > what efforts has been made to simulate the METHODOLOGY of human > thought on a computer? For example, has any research been done > to find the electrical and chemical sequence that occurs when > someone is typing a line of text (like what I just did)?? > > Mike > -- > > Real Life: Michael Bloomberg > MILNET: bloomber@nosc > UUCP: [ihnp4,akgua,decvax,dcdwest,ucbvax]!sdcsvax!noscvax!bloomber The human brain is not necessarily a good model for computation. Witness robots that do not necessarily look like humans like Unimates. Research is being done in this area. When I was an undergrad, I held a work-study job in a psychology department and a summer position with a firm (Infomation Magnetics) designing magnetic media. In the latter, we discussed using media such as DNA: problems: e.g., UV light, advantages: reproducibility, low cost. The biggest problem is speed. This is all chemical at the molecular level (no flames please). It could be argued that "parallelism" might make up for the speed, but I remain unconconvenced. As for "software" talk to the AI people (in particular minksy, since he reads the ai list). There are people working in this area, but it doesn't excite me like optical computing. --eugene miya NASA Ames Research Center {hplabs,ihnp4,dual,hao,vortex}!ames!aurora!eugene emiya@ames-vmsb.ARPA
dudek@utai.UUCP (Gregory Dudek) (02/01/85)
In answer to the question of whether people have attempted to simulate the methodology of the human brain (and the particular example of what happens while typing a line of text) I thought I'd mention that both physiologists, psychologists and computer scientists are attempting to build models of some aspects of the brain. The way the question was posed seemed to imply this was a relatively easy problem. As far as I can tell, it is extremely difficult and poorly understood. In particular, a lot of effort has gone into trying to guess just what the heck the biological visual system is doing in the hope of constructing (at least) a simple computer vision system. As yet, a lot of work remains to be done.
roy@phri.UUCP (Roy Smith) (02/13/85)
> > I have been reading some articles about alternate computer architectures > > and am curious about the following: > > 1. What work has been done in actually building an optical computer?? Of interest to anybody who has been following this discussion should be this recent article: %A Benjamin Arazi %D January 1985 %T An Electrooptical Adder %J Proceedings of the IEEE %V 73 %N 1 %P 162-163 %X A prototype for a binary adder, in which the carry propagation is handled by light signals is suggested, thus enabling a fast execution of addition operation even for large operands. -- The opinions expressed herein do not necessarily reflect the views of the Public Health Research Institute. {decvax,ihnp4}!vax135!timeinc\ >!phri!roy (Roy Smith) {allegra,rocky2}!cubsvax/