![[Picture of Newton]](newton2.gif)
Isaac Newton: the first physicist.
Isaac Newton is popularly remembered as the man who saw an apple fall
from a tree, and was inspired to invent the theory of gravity. If you
have grappled with elementary physics then you know that he
invented calculus and the three laws of motion upon which all of
mechanics is based. More fundamentally, Newton's mathematical approach has
become so basic to all of physics that he is generally regarded as
the father of the clockwork universe: the first,
and perhaps the greatest, physicist.
The Alchemist
In fact, Newton was deeply opposed to the mechanistic conception of
the world. A secretive alchemist and heretical theologian, he
performed countless experiments with crucibles and furnaces in his
Cambridge chambers, analyzing the results in unmistakably alchemical
terms. His written work on the subject ran to more than a million
words, far more than he ever produced on calculus or mechanics
[21]. Obsessively religious, he spent years correlating biblical
prophecy with historical events [319ff]. He became deeply convinced
that Christian doctrine had been deliberately corrupted by the false
notion of the trinity, and developed a vicious contempt for
conventional (trinitarian) Christianity and for Roman Catholicism in
particular [324]. Newton's religious and alchemical interests were
not tidily separated from his scientific ones. He believed that God
mediated the gravitational force [511](353), and opposed any attempt
to give a mechanistic explanation of chemistry or gravity, since that
would diminish the role of God [646]. He consequently conceived such
a hatred of Descartes, on whose foundations so many of his
achievements were built, that at times he refused even to write his
name [399,401].
The Man
Newton was rigorously puritanical: when one of his few friends told
him "a loose story about a nun", he ended their friendship (267). He
is not known to have ever had a romantic relationship of any kind, and
is believed to have died a virgin (159). Furthermore, he had no
interest in literature or the arts, dismissing a famous collection of
sculpture as "stone dolls" [581]. In short, Newton was a mathematical
mystic, convinced that he shared a privileged relationship with God
and obsessively devoted to finding how He had constructed
the universe (205,285,510). He thought of himself as the
sole inventor of the calculus, and hence the greatest mathematician
since the ancients, and left behind a huge corpus of unpublished work,
mostly alchemy and biblical exegesis, that he believed future
generations would appreciate more than his own (199,511).
Many biographers have conjectured that the roots of Newton's unquenchable
competitiveness and paranoia lie in his mother's remarriage and
abandonment of him at the age of 3 (6). Even though these
unattractive qualities caused him to waste huge amounts of time and
energy in ruthless vendettas against colleagues who in many cases had
helped him (see below), they also drove him to the extraordinary
achievements for which he is still remembered. And for all his
arrogance, Newton's own summary of his life (574) was beautifully humble:
"I do not know how I may appear to the world, but to myself I seem to have
been only like a boy, playing on the sea-shore, and diverting myself, in
now and then finding a smoother pebble or prettier shell than ordinary,
whilst the great ocean of truth lay all undiscovered before me."
Before Newton
Today, Newton is remembered as the founding figure of calculus,
mechanics, and optics. Given his great intelligence and obsessive
temperament, it is no accident that he was able to make crucial
contributions to the outstanding scientific questions of his age.
Newton was born into a time of intellectual ferment far more profound
than that accompanying the rise of relativity and quantum uncertainty
in the 1920's and '30's. By the time he arrived at Trinity College
Cambridge in 1661, the problems with which he was to grapple during
his career had already been formulated and were gradually being solved
by the tiny elite of European mathematicians and natural philosophers:
- Calculus. Descartes, in 1637, pioneered the use of coordinates to
turn geometric problems into algebraic ones, a method that Newton was
never to accept [399]. Descartes, Fermat, and others investigated
methods of calculating the tangents to arbitrary curves [28-30].
Kepler, Cavalieri, and others used infinitesimal slices to calculate
volumes and areas enclosed by curves [30], but no unified treatment of
these problems had yet been found.
- Mechanics & Planetary motion. The elliptical orbits of the planets
having been established by Kepler, Descartes proposed the idea of a
purely mechanical heliocentric universe, following deterministic laws,
and with no need of any divine agency [15], another anathema to
Newton. No one imagined, however, that a single law might explain
both falling bodies and planetary motion. Galileo invented the
concept of inertia, anticipating Newton's first and second laws of
motion (293), and Huygens used it to analyze collisions and circular
motion [11]. Again, these pieces of progress had not been synthesized
into a general method for analyzing forces and motion.
- Light. Descartes claimed that light was a pressure wave, Gassendi
that it was a stream of particles (corpuscles) [13]. As might be
guessed, Newton vigorously supported the corpuscular theory. White
light was universally believed to be the pure form, and colors were
some added property bequeathed to it upon reflection from matter
(150). Descartes had discovered the sine law of refraction (94), but
it was not known that some colors were refracted more than others. The
pattern was the familiar one: many pieces of the puzzle were in place,
but the overall picture was still unclear.
The Natural Philosopher
Between 1671 and 1690, Newton was to supply definitive treatments of
most of these problems. By assiduous experimentation with prisms he
established that colored light was actually fundamental, and that it
could be recombined to create white light. He did not publish the
result for 6 years, by which time it seemed so obvious to him that he
found great difficulty in responding patiently to the many
misunderstandings and objections with which it met [239ff].
He invented differential and integral calculus in 1665-6, but failed
to publish it. Leibniz invented it independently 10 years later, and
published it first [718]. This resulted in a priority dispute which
degenerated into a feud characterized by extraordinary dishonesty and
venom on both sides (542).
In discovering gravitation, Newton was also barely ahead of the rest
of the pack. Hooke was the first to realize that orbital motion was
produced by a centripetal force (268), and in 1679 he suggested an
inverse square law to Newton [387]. Halley and Wren came to the same
conclusion, and turned to Newton for a proof, which he duely supplied
[402]. Newton did not stop there, however. From 1684 to 1687 he
worked continuously on a grand synthesis of the whole of mechanics,
the "Philosophiae Naturalis Principia Mathematica," in which he
developed his three laws of motion and showed in detail that the
universal force of gravitation could explain the fall of an apple as
well as the precise motions of planets and comets.
The "Principia" crystallized the new conceptions of force and inertia
that had gradually been emerging, and marks the beginning of
theoretical physics as the mathematical field that we know today. It
is not an easy read: Newton had developed the idea that geometry and
equations should never be combined [399], and therefore refused to use
simple analytical techniques in his proofs, requiring classical
geometric constructions instead [428]. He even made his Principia
deliberately abstruse in order to discourage amateurs from feeling
qualified to criticize it [459].
The Principia was Newton's crowning
achievement. He revised and extended it, but most of the rest of his
life was spent in administrative work as Master of the Mint and as
President of the Royal Society, a position he ruthlessly exploited in
the pursuit of vendettas against Hooke (300ff,500), Leibniz (510ff),
and Flamsteed (490,500), among others.
He kept secret his disbelief in Christ's divinity right up until
his dying moment, at which point he refused the last rites,
at last openly defying the church (576). His alchemical corpus was never
publicized, and has only recently received serious attention
from intellectual historians.
Numbers in brackets [..] are references to pages in Richard's Westfall's
"Never at Rest" , Cambridge University Press, 1980.
Numbers in parentheses (..) are references to Gale Christianson's
"In the Presence of the Creator",
The Free Press (Macmillan), 1984.
For more, see:
Andrew McNab's "newton.org.uk"
[As of early 2002 this site has disappeared]
Medieval, Renaissance,
Reformation: Western Civilization, Act II
Copyright © Mark Alford (1995)
alford(at)physics.wustl.edu
Mark Alford's home page