[TUHS] daemons are not to be exorcised

Nelson H. F. Beebe beebe at math.utah.edu
Wed Mar 21 07:32:33 AEST 2018

Peter Guthrie Tait (1831--1901) seems to have recorded the oldest
mention of the thermodynamic demon of James {Clerk Maxwell} in the
page 213 image from Tait's book ``Sketch of Thermodynamics'' at


that was posted to this list by Bakul Shah <bakul at bitblocks.com> on
Tue, 20 Mar 2018 12:10:37 -0700.

I've been working on a bibliography (still unreleased) of Clerk
Maxwell, and the oldest reference that I had so far found to Maxwell's
demon is from an address by Sir William Thomson (later raised to Lord
Kelvin) entitled

	The sorting demon of Maxwell: [Abstract of a Friday evening
	Lecture before the Royal Institution of Great Britain,
	February 28, 1879]
	Proceedings of the Royal Institution of Great Britain 9,
	113--114 (1882)

However, I've not been able to find that volume online.  Hathi Trust
has only volumes 30--71, with numerous holes, and often, it will not
show page contents at all.  The journal issue is old enough that few
university libraries are likely to have it, but it is probably
available through the Interlibrary Loan service.

I had also recorded

	Harold Whiting
	Maxwell's demons
	Science (new series) 6(130), 83, July 1885

	W. Ehrenberg
	Maxwell's demon
	Scientific American 217(5) 103--110, November 1967

plus numerous later papers and books.

I also went through a score of books on my shelf about physics or
thermodynamics, and finally found a brief mention of Maxwell's demon
in G. N. Lewis & M. Randall's famous text ``Thermodynamics'', first
published in 1923 (I have a 1961 reprint).  The other books that I
checked remain strangely silent on that topic.

The Oxford English Dictionary (OED) online has this definition and

>> ...
>> Maxwell's demon n. (also Maxwell demon) an entity imagined by Maxwell
>> as allowing only fast-moving molecules to pass through a hole in one
>> direction and only slow-moving ones in the other direction, so that if
>> the hole is in a partition dividing a gas-filled vessel, one side
>> becomes warmer and the other cooler, in contradiction of the second
>> law of thermodynamics.
>> 1879 W. Thomson in Proc. Royal Inst. 9 113 Clerk Maxwell's `demon' is
>>      a creature of imagination.., invented to help us to understand the
>>      `Dissipation of Energy' in nature.
>> 1885 Science 31 July 83/1 (heading) Maxwell's demons.
>> 1956 E. H. Hutten Lang. Mod. Physics iv. 152 It would require a
>>      Maxwell demon..to select the rapidly moving molecules according to
>>      their velocity and concentrate them in one corner of the vessel.
>> 1971 Sci. Amer. Sept. 182/2 Maxwell's demon became an intellectual
>>      thorn in the side of thermodynamicists for almost a century. The
>>      challenge to the second law of thermodynamics was this: Is the
>>      principle of the increase of entropy in all spontaneous processes
>>      invalid where intelligence intervenes?
>> 1988 Nature 27 Oct. 779/2 Questions about the energy needed in
>>      measurement began with Maxwell's demon.
>> ...

For the word `daemon', the OED has this:

>> ...
>> Etymology: Probably an extended use of demon ....
>> A program (or part of a program), esp. within a Unix system, which
>> runs in the background without intervention by the user, either
>> continuously or only when automatically activated by a particular
>> event or condition.  A distinction is sometimes made between the form
>> daemon, referring to a program on an operating system, and demon,
>> referring to a portion of a program, but the forms seem generally to
>> be used interchangeably, daemon being more usual.
>> 1971 A. Bhushan Request for Comments (Network Working Group)
>>      (Electronic text) No. 114. 2 The cooperating processes may be
>>      `daemon' processes which `listen' to agreed-upon sockets, and
>>      follow the initial connection protocol.
>> 1983 E. S. Raymond Hacker's Dict. 53 The printer daemon is just a
>>      program that is always running; it checks the special directory
>>      periodically, and whenever it finds a file there it prints it
>>      and then deletes it.
>> 1989 DesignCenter ii. 41/3 The file server runs a standard set of
>>      HP-UX system and network daemons.
>> 1992 New Scientist 18 Jan. 35/2 These programs, which could recognise
>>      simple patterns, were made up of several independent
>>      information-processing units, or `demons', and a `master
>>      demon'.
>> 2002 N.Y. Times 7 Mar. d4/5 A mailer daemon installed on an e-mail
>>      system can respond to a piece of incorrectly addressed e-mail
>>      by generating an automated message to the sender that the
>>      message was undeliverable.
>> ...


>From The Hacker's Dictionary (1983), reproduced in the Emacs info node
Jargon, I find another `explanation' of daemon:

>> ...
>> :daemon: /day'mn/ or /dee'mn/ /n./  [from the mythological
>>    meaning, later rationalized as the acronym `Disk And Execution
>>    MONitor'] A program that is not invoked explicitly, but lies
>>    dormant waiting for some condition(s) to occur.  The idea is that
>>    the perpetrator of the condition need not be aware that a daemon is
>>    lurking (though often a program will commit an action only because
>>    it knows that it will implicitly invoke a daemon).  For example,
>>    under {{ITS}} writing a file on the {LPT} spooler's directory
>>    would invoke the spooling daemon, which would then print the file.
>>    The advantage is that programs wanting (in this example) files
>>    printed need neither compete for access to nor understand any
>>    idiosyncrasies of the {LPT}.  They simply enter their implicit
>>    requests and let the daemon decide what to do with them.  Daemons
>>    are usually spawned automatically by the system, and may either
>>    live forever or be regenerated at intervals.
>>    Daemon and {demon} are often used interchangeably, but seem to
>>    have distinct connotations.  The term `daemon' was introduced to
>>    computing by {CTSS} people (who pronounced it /dee'mon/) and
>>    used it to refer to what ITS called a {dragon}.  Although the
>>    meaning and the pronunciation have drifted, we think this glossary
>>    reflects current (1996) usage.
>> ...

- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
- Department of Mathematics, 110 LCB    Internet e-mail: beebe at math.utah.edu  -
- 155 S 1400 E RM 233                       beebe at acm.org  beebe at computer.org -
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