[TUHS] daemons are not to be exorcised

[Dan Cross]

On Tue, Mar 20, 2018 at 3:10 PM, Bakul Shah <bakul at bitblocks.com> wrote:

> On Mar 20, 2018, at 11:46 AM, Clem Cole <clemc at ccc.com> wrote:
> >
> > On Tue, Mar 20, 2018 at 2:24 PM, Bakul Shah <bakul at bitblocks.com> wrote:
> > On Tue, 20 Mar 2018 14:04:38 -0400 Dan Cross <crossd at gmail.com> wrote:
> > Dan Cross writes:
> > >
> > > On Tue, Mar 20, 2018 at 1:56 PM, George Michaelson <ggm at 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.
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