gwr@cord.UUCP (03/29/87)
this came up in a class last week; we came up with a few interesting ideas but no real answers. Why are "daemons" called "daemons"? that is, what is the derivation of that name? We got answers like "something to do with Maxwell's daemon" and "maybe if you say the magic words (i.e. satisfy the conditions to fire the daemon) then the daemon wakes up". anybody know the right answer?? mail to me, and I'll summarize to the net. thanks jerry allegra!cord!gwr gwr@cord.garage.nj.att.com
flowers@ucla-cs.UUCP (03/30/87)
>this came up in a class last week; we came up with a few interesting ideas but >no real answers. Why are "daemons" called "daemons"? that is, what is the >derivation of that name? From "Pattern Recognition by Machine", by Selfridge and Neisser, Scientific American 1960, in describing the Pandemonium model they proposed: In parallel processing all the questions would be asked at once, and all the answers presented simultaneously to the decision maker. Different combinations identify the different letters. One might think of all the various features as being inspected by little demons, all of whom then shout the answers in concert to a decision-making demon. From this conceit comes the name "Pandemonium" for parallel processing. This paper was reprinted in the seminal and still useful book _Computers and Thought_, Feigenbaum and Feldman, eds., 1963. Anyway, Selfridge and Neisser have some earlier publications about pattern matching and the Pandemonium model which probably introduced the idea of demons. I don't know if their use of the term was inspired by any prior specific use. Around 1970 demons were utilized and popularized by Charniak's Ph.D. thesis. Margot Flowers, Asst. Prof., UCLA AI Lab Flowers@CS.UCLA.EDU [or Flowers@UCLA-CS for old host tables] ...!{ucbvax|ihnp4}!ucla-cs!flowers (uucp)
port@iuvax.UUCP (03/30/87)
The use of daemon in Unix for a program that `wakes up' and does some task whenever it is required is actually a regular use of the word. It isnt one of those typical computing terms that has an arcane history (one thinks of the derivation of `nroff, grep, awk, winchester,' etc). The word is classical Greek for any kind of spirit or genie -- some kind of minor deity. In Latin they borrowed the Greek word and spelled it daemon (for Greek daimon-ion), to descdribe such spirits. For the Christians, of course, all such deities were paganisms so, they were viewed as evil. Thus the English word demon has the strong flavor of evil about it. But we also seem to have split the word in two, so now the original pagan meaning has been restored in modern English with a more classical spelling as daemon. The use in `Maxwell's daemon' is in just this sense. Similarly, in the 1950's Selfridge proposed a parallel model of the perception of alphabetic letters that had `daemons' for each letter. They were competing with each other to `find themselves' in the incoming visual features. The one that `shouted' the loudest was the one that caused a `decision demon' to issue a conclusion. The use of this word for independent procesess that seem to have a `will of their own' as in operating systems is very appropriate.