On Tue, Mar 20, 2018 at 3:10 PM, Bakul Shah <bakul(a)bitblocks.com> wrote:
On Mar 20, 2018, at 11:46 AM, Clem Cole
<clemc(a)ccc.com> wrote:
On Tue, Mar 20, 2018 at 2:24 PM, Bakul Shah <bakul(a)bitblocks.com> wrote:
On Tue, 20 Mar 2018 14:04:38 -0400 Dan Cross <crossd(a)gmail.com> wrote:
Dan Cross writes:
>
> On Tue, Mar 20, 2018 at 1:56 PM, George Michaelson <ggm(a)algebras.org>
wrote:
I think daemon/demon came from printers demon, which is carved into
the government printing office in Brisbane. the
printers demon is the
one which stuffed up letters in the tray, to make printers tear their
hair out. Did I say tray? I meant case, upper case, the one above,
with the big letters, and lower case, the case with the little
letters. oh dear. really? is that why they are cases?
While this story (and the others I trimmed for brevity) is (are) great,
"daemon" is actually from the Greek, I believe: an intermediary between
humans (users) and the gods (the kernel).
From
http://ei.cs.vt.edu/~history/Daemon.html
Fernando J. Corbato: ... Our use of the word daemon (@
Project MAC in 1963) was inspired by the Maxwell's daemon of
physics and thermodynamics. (My background is Physics.)
Maxwell's daemon was an imaginary agent which helped sort
molecules of different speeds and worked tirelessly in the
background. We fancifully began to use the word daemon to
describe background processes which worked tirelessly to
perform system chores.
Right -- that is what I was under the impression from where the term
came for
computer use. Although, I was also under the impression that
Maxwell had taken the term from ideas from some his Cambridge colleagues
that were working on human thought and described the ideas of these daemons
running around in your head supporting things like vision, hearing and your
other senses. The later was formalized I believe years later by Oliver
Suthridge (IIRC my Cog Psych of many years ago) - into the something like
the Pandemonium model of cognition.
This origin must've been better known 30+ years back because I
remembered this as well. To check I first looked at the Wikipedia
entry for Maxwell's demons (I learned new facts but also confused
myself as I couldn't see the connection).
As to where Maxwell got his demons, see
https://archive.org/stream/lifescientificwo00knotuoft#page/212/mode/2up
and page 214 as well:
Oh how interesting.
Of note Maxwell's first quoted letter describes the theory in terms of
"finite beings"; Wikipedia claims it was Lord Kelvin who first labeled them
"demons" in a paper published in the journal "Nature" in 1879
(citation
here:
https://www.nature.com/articles/020126a0; full text here:
https://zapatopi.net/kelvin/papers/the_sorting_demon_of_maxwell.html) and
that seems to be backed up by what you quoted below:
Maxwell constructed the following Catechism:
"Concerning demons.
"1. Who gave them this name? Thomson
"2. What were they by nature? Very small BUT lively beings incapable of
doing work but also able to open and shut valves which move without
friction or inertia.
etc.
Here, Maxwell seems to be corresponding with Thomson in 1867 but it is not
until more than a decade later Thomson writes his nature article which
clearly associates the concept with to the Greek notion. Kelvin's
article seems to be describing a lecture, and further seems to imply that
the concept was ideas recognized -- at least in scientific circles, by 1879.
Anyway, by his own admission Corbato came into contact with the concept via
physics and uses it on Multics to describe programs doing more or less what
any of us would think of a "daemon" doing, and from there it went into
Unix. I wonder where the archaic spelling came from.
So it does come from the Greek notion, albeit in a roundabout fashion. Does
that seem accurate?
i.e. I think the term was used first in Cognition,
then to Physics and
finally to Computers.
As for Paul's comment about the daemons. Yes, Kirk McKusick who
actually
drew the original BSD daemon with purple sneakers, was wearing the
infamous blue tee with said logo out walking on the street, as one someone
else in the party (maybe Sam Leffler) sporting a 10 anniversary USENIX
shirt in San Antonio many years ago, which has the daemons shown top of a
PDP-11 with pipes, the null device, et al. He has quite a tale of the
experience.
BSD's daemon is much cuter than that damned nemesis of Batman :-)
I'm mildly surprised that such a thing would happen in San Antonio, which
is a bit more cosmopolitan than much of the rest of Texas. But only mildly.
- Dan C.