Demons in Science
January 25, 2021
The 
supernatural beings known as 
angels are a part of many 
religions, and they are mentioned often in the 
Bible and other 
Judeo-Christian religious texts.  Their function is to relay the intentions of 
God to 
humans, and the 
word, angel, derives from the 
Greek word, ἄγγελος, angelos (messenger).  The number of angels, as stated in 
Revelation 5:11, is ten thousand times ten thousand, or 100 million.
 
An angel (left) and a demon. Angels are often depicted playing a harp.  Popular culture says that the fiddle is the devil's musical instrument.  (Left image, an angel from The Celestial Country, a 1900 publication by Edwin S. Gorham; right image, an 1863 illustration by Louis Le Breton (1818-1866) from Tables tournantes dans le Dictionnaire infernal par Collin de Plancy; both from Wikimedia Commons)
While every 
experimenter hopes that a 
guardian angel is assisting him in his 
experiments, there are no specific angels mentioned in the 
scientific literature.  There are, however, a few 
demons, and these are discussed in a recent book, 
Bedeviled: A Shadow History of Demons, by 
Jimena Canales.[1]  This book was 
reviewed in a recent issue of 
Science by 
Jan G. Michel of the 
Department of Philosophy of Religion and Science, 
Ruhr-Universität Bochum (Bochum, Germany).[2]
Alphonso de Spina (fl. 1500), a 
Spanish Franciscan Catholic bishop, somehow determined that the number of demons was 133,316,666. This number is nearly a factor of five too large, if we believe that the 
traditional number of demons is one third of the angels.  
Paradise Lost, a 1667 
epic poem by 
John Milton (1608–1674), states that 
Satan, in his 
rebellion against God, "Drew after him the third part of Heaven's host."[3]  The most famous 
quotation from Paradise Lost is Satan's declaration, "Better to 
reign in 
Hell than 
serve in 
Heaven."
In 
Bedeviled: A Shadow History of Demons, Canales writes about three principal demons relating to 
science; namely, 
Laplace's demon, 
Maxwell's demon, and 
Descartes' demon.  Laplace's demon, as imagined by 
French polymath, 
Pierre-Simon Laplace (1749-1827), has knowledge of the precise location and 
momentum vector of every 
atom in the 
universe.  This 
knowledge allows a 
calculation of any future state of the universe according to the 
laws of 
classical mechanics.  There have been many arguments for why this demon would not be successful in its calculations.  We can't invoke 
quantum mechanics, since the realm of the question is the classical mechanics known to Laplace.  Furthermore, we can't invoke 
chaos theory, since all quantities are supposedly known to adequate 
precision.
 
Three demon masters, René Descartes (1596-1650), Pierre-Simon Laplace (1749-1827), and James Clerk Maxwell (1831-1879), responsible for the eponymous Laplace's demon, Maxwell's demon, and Descartes' demon.  (Portrait of René Descartes by Gérard Edelinck from a bust by Frans Hals (left), image of Pierre-Simon Laplace (center), and an engraving of James Clerk Maxwell by G. J. Stodart from a photograph by Fergus of Greenock (right) all from Wikimedia Commons.)
The most plausible reason for the impossibility of Laplace's demon's success is the 
computational power required.  All 
computation requires a 
memory of a calculation's intermediate terms, and the universe has a limit on 
information content.  This limit amounts to 10
120 bits, a number derived from 
fundamental physical constants, and this would be the minimum size of a computation for 
simulating the universe.[4-6] That number, combined with the limitation imposed by the 
speed of light on information transfer, requires that any computation that needs more data than this can't be done in less time than the 
age of the universe.  This presumes that the demon is bound by the 
laws of physics, a necessary condition; otherwise, anything would be possible.
Maxwell's demon is a part of a 
thought experiment devised in 1867 by 
physicist, 
James Clerk Maxwell (1831-1879). In this thought experiment, a demon violates the 
second law of thermodynamics, the law concerning 
entropy that proves that a 
perpetual motion machine can't function by extracting 
environmental thermal energy to produce 
mechanical work.
The demon controls a 
door between two 
gas-filled 
chambers.  He opens the door to allow only faster (hotter) 
gas molecules to enter one chamber, and only slower (colder) gas molecules to pass into the other.  Maxwell's demon can't function as envisioned, since he's a part of the 
thermodynamic system.  He creates more entropy than he could ever eliminate in doing his task, since the act of acquiring information on 
molecular speed expends energy.
 
Principle of Maxwell's demon.  The door separating the two chambers opens to allow only hot gas molecules to pass from A to B, and cold molecules to pass from B to A.  (Modified Wikimedia Commons image by Htkym.)
Descartes' demon acts in a way that 
precludes any 
scientific truth.  As imagined by French 
mathematician, 
scientist, and 
philosopher, 
René Descartes (1596-1650) in his 1641 
Meditations on First Philosophy, this demon presents to men a complete 
illusion of an 
external world.  As Descartes writes, "I shall consider myself as not having 
hands or 
eyes, or 
flesh, or 
blood or 
senses, but as falsely 
believing that I have all these things."  You might see an 
analogy of this with the recent idea that 
we are part of a computer simulation.
Descartes dismisses this idea by stating, "je pense, donc je suis," which is most commonly rendered as 
cogito, ergo sum; that is, "I think, therefore I am."  The reasoning is that such 
self-awareness could not be manipulated.  This idea was earlier stated around 
500 BC by 
Parmenides of Elea (fl. late sixth - early fifth century BC). Parmenides wrote in his book, 
On Nature, in the section known as 
the way of truth, "For it is the same thing that can be thought and that can be."[7]
 
"For it is the same thing that can be thought and that can be."  A portion of On Nature by Parmenides of Elea.  (From Ref. 7.)[7]
While on the topic of demons, we should also address the interesting question of which place is hotter, heaven or hell.  Heaven is often associated with a bright 
white light, while hell is a place of 
fire and brimstone, brimstone being an 
archaic term for 
sulfur.  The 
melting point of sulfur is 115.21 
°C (388.36 
K, 239.38 
°F), and its 
boiling point is 444.6 °C (717.8 K, 832.3 °F), so 
burning sulfur can have a 
temperature between those extremes (assuming 
atmospheric pressure).  The temperature of a 
blackbody emitting white light is 5,225°C (5,500 K, 9440.33 °F).
References:
-   Jimena Canales, "Bedeviled: A Shadow History of Demons in Science," Princeton University Press, November 10, 2020, 416 pp., ISBN: 978-0691175324 (via Amazon).
 -   Jan G. Michel, "Imaginary demons and scientific discoveries," Science, vol. 370, no. 6518 (November 13, 2020), p. 772, DOI: 10.1126/science.abd9851.
 -   John Milton, "Paradise Lost," at Project Gutenberg.
 -   S. Lloyd, "Ultimate physical limits to computation," Nature, vol. 406, pp. 1047-1054 (August 31, 2000). https://doi.org/10.1038/35023282.
 -   Seth Lloyd, "Computational Capacity of the Universe," Phys. Rev. Lett., vol. 88, Article no. 237901, May 24, 2002, DOI:https://doi.org/10.1103/PhysRevLett.88.237901.
 -   J.R. Minkel, "If the Universe Were a Computer," Physical Review Focus, vol. 9, no. 27 (May 24, 2002).
 -   Parmenides, "Fragments," Original Greek text by Diels, English translation by John Burnet, PDF File from Philoctetes.