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Newton's God hypothesis

from Principia, p. 1157:

Newton could not solve the minute effects of gravity between the
planets, which he felt, would destabilize them and cause them to fall out of
orbit and eventually into the sun.  Apparently he believed that from time to
time, God interferes to fix things (see these excerpts from  Keith Ward's
Pascal's Fire).  This has been called the "God of thae Gaps".

       The six primary Planets are revolv'd about the Sun, in circles
       concentric with the Sun, and with motions directed towards the same
       parts, and almost in the same plane. . . . But it is not to be
       conceived that mere mechanical causes could give birth to so many
       regular motions. . . . This most beautiful System of the Sun,
       Planets, and Comets, could only proceed from the counsel and
       dominion of an intelligent and powerful Being.  And lest the systems
       of the fixed Stars should, by their gravity, fall on each other
       mutually, he hath placed those Systems at immense distances from one
       another.
	        [Principia, General Scholium, tr. A. Motte, 1729; end of Book
		3. p.1157 in Hawking]

The effects of these minute forces were worked out by Laplace a century
later, which showed that stable behaviour on much larger time-scales was
possible.

To this Hawking has contributed just 40 pages of commentary.
The selections are pure physics hot from the cow with no interpretive notes
whatsoever.
Like Hawking's other books, this one will appear, pages uncut, on coffee
tables across the country. I identify no other use for it.-- Gerry Rising
http://www.acsu.buffalo.edu/~insrisg/bookmarks/bk04/0729Giants.htm

Owen Gingrich review

http://www.nature.com/nature/journal/v421/n6924/full/421694a.html

Each translation has apparently been chosen for its easy availability, and
each now has a more nuanced version currently in print elsewhere. Take
Newton's Principia, for example. For years the standard English version was
Florian Cajori's modernization of Andrew Motte's 1729 translation. 

With the appearance of I. B. Cohen's magisterial translation in 1999, the
University of California Press withdrew Cajori's version. On The Shoulders
of Giants reverts back to Motte's dated translation.

The choice of Galileo's text, here titled 'Dialogues Concerning Two
Sciences', is particularly curious. Modern scholars call the book Discourses
or Two New Sciences to distinguish it from his Dialogue on the Two Great
World Systems, which was Galileo's classic defence of heliocentric cosmology
that got him into trouble with the Inquisition. 

The dust-jacket mentions that one of the texts included was considered so
"dangerous" that its author was accused of heresy, as if the Dialogue on
the Two Great World Systems were found here. This also seems to be what
Hawking expected, because in his introduction he writes: "In Dialogues
Concerning Two Sciences, Galileo's characters, Salviati and Sagredo, put
forward persuasive arguments in support of Copernicus." 
So they do in the Dialogue on the Two Great World Systems, but this work is
not included here.

Kepler's Harmonices mundi libri V is an especially inept selection. This
fifth book does include a splendid nugget — Kepler's mathematical
relationship between the cube of the planet's distance from the Sun and the
square of its period — but it is an idiosyncratic work, here presented
entirely out of context. And its title is erroneously translated as
'Harmonies of the World'. Harmonices looks like a Latin plural, but Kepler
used a Greek genitive singular ending, because, as a great unifier, he
believed in a singular 'Harmony of the World'.

Kepler's Astronomia nova ranks beside Copernicus' De revolutionibus and
Newton's Principia in the triumvirate of technical landmarks in the
scientific revolution, but it's not here. And it would have been a redeeming
achievement to have included William Donahue's scarce translation of Kepler's
New Astronomy in this collection instead of part of Harmony of the World.

The commentaries on each author contain congenial anecdotes, some
accurate historical data, and a dose of modern mythology. Unfortunately, the
opening vignette is littered with errors. Hawking stumbles in the very first
line, calling Copernicus a priest, which he most surely was not, although he
was a canon and legal officer at Frauenburg cathedral. Hawking is in good
company here, because Galileo also described Copernicus as a priest, but
Galileo had propagandistic reasons that Hawking lacks.

According to Hawking, Aristotle argued that the Earth was round because
hulls of ships sailing out to sea disappeared over the horizon before the
sails. The argument was made by Ptolemy half a millennium later, but not by
Aristotle. Hawking's introduction also says that Western Christendom placed
Hell beyond the stars; that Copernicus became a professor of astronomy at
Bologna; that he completed De revolutionibus in 1530; that Rheticus
relinquished a chair in mathematics at Wittenberg to study under Copernicus;
that Copernicus used equants to account for the motion of the Earth; that
Osiander placed the word 'hypothesis' on the title page of Copernicus' book;
and that the world had scarcely become known to be round when Copernicus
wrote. None of this is true. No bibliography is provided, so it is difficult
to ascertain the source of this disaster. Fortunately the other introductions
are not as bad: the Kepler introduction benefits from using the Dictionary of
Scientific Biography as its unacknowledged source, for example.

The most interesting part of this book is the general introduction; this
is quintessential and thoughtful Hawking, clearly carrying his own stamp. He
writes about the anthropic principle: "If the ultimate theory made a unique
prediction for the state of the universe and its contents, it would be a
remarkable coincidence that this state was in the small subset that allows
life." It is almost worth the price of the book to get this quotation.