Page 71 - BBC History The Story of Science & Technology - 2017 UK

So how did he know that there were of”. Would Christ, for example, have had to
mountains and valleys on the Moon? It was Would Christ have undergo another Passion upon the Moon to
not possible simply to ‘see’ that the surface had to undergo save such human souls as lived there?
of the Moon was not smooth, even with
Galileo’s excellent telescopes. His argument another Passion Have we not lately in the moon,
had to be more complex. Found a new world, to th’old unknown?
Galileo studied very carefully the slowly upon the Moon to Discovered seas and lands Columbus
moving boundary (the ‘terminator’) And Magellan could never compass?
between the bright, sunlit parts of the Moon save souls there? Made mountains with our tubes appear,
and the dark part still in shadow. In the first And cattle grazing on them there?
place, he reported, “the boundaries of (Samuel Butler, Hudibras, 1664)
shadow and light in the Moon are seen to be accommodate Galileo’s conclusions,
uneven and wavy”. Even more tellingly, arguing, for example, that although the For many people, theological technicalities
“many bright points appear within the lunar mountains did exist, they were were less important than the exciting
darkened portion of the Moon, completely encased in a perfectly spherical outer layer parallels with the ongoing voyages of
divided and separated from the illuminated of celestial crystal. discovery on Earth: were there new worlds
part and at a considerable distance from it. By the early 17th century, the Aristotelian to explore in the solar system comparable
After a time these [points] gradually increase cosmology was already under attack. The to the New World on Earth? Galileo himself
in size and brightness, and an hour or two radical Sun-centred cosmology of Nicolaus was often compared, especially in poetry,
later they become joined with the rest of the Copernicus (1473–1543) was increasingly to a new and greater Columbus. A colonial
lighted part which has now increased in widely known and discussed. Galileo’s initiative was never far behind. “Do but
size.” This, said Galileo, is exactly what telescopic discoveries did not definitely consider the pleasure and profit of those
happens on the Earth: “before the rising of prove the Copernican theory, but they later discoveries in America,” Bishop John
the Sun, are not the highest peaks of the certainly undermined the established Wilkins urged his readers, “and we must
mountains illuminated by the Sun’s rays Aristotelian hypothesis. needs conclude this [world in the Moon] to
while the plains remain in shadow? Does not Nevertheless, common-sense objection to be inconceivably beyond it.” In coming
the light go on spreading while the larger the supposed motion of the Earth remained, years, the Moon was indeed claimed in turn
central parts of those mountains are understandably enough, very strong. Such by Spaniards, Italians, Dutch, and many
becoming illuminated? And when the Sun discoveries as the moons of Jupiter or, later others beside the British.
has finally risen, does not the illumination of the same year, the phases of Venus – both Gradual technical improvement in
plains and hills finally become one?” quite difficult to observe without a good telescope design produced a new generation
Galileo’s ideas about the Moon were – and telescope – were undeniably influential of lunar map-makers. The Selenographia
were meant to be – provocative. The among professional astronomers. In the (1647) of Johannes Hevelius (1611–87) set
understanding of nature, the “natural popular imagination, however, it was the the cartographic standard for almost the
philosophy” taught in European universities alleged Earth-like nature of the Moon that next 150 years. It was the Almagestum
at the time, was still largely dominated by probably had the profoundest impact in Novum (1651) of the Jesuit Giovanni
the system of the ancient Greek philosopher launching the Earth into space to join the Riccioli (1598–1671), however, that
Aristotle (384–322 BC). Aristotle had other planets in orbit around the Sun. established the basic modern system for
argued, very elegantly to be sure, that there naming lunar features. Without Riccioli,
was a fundamental difference between the Mountains on the Moon the Apollo astronauts would have stepped
nature and very substance of the heavens Galileo’s suggestion that the Moon was rug- out not into the Sea of Tranquillity but,
and of the Earth. ged, mountainous, like the Earth, had instead, into ‘the Black Sea’ or perhaps
The Earth was stationary at the centre of further significant scientific and theologi- even ‘the Belgian Sea’.
the universe, surrounded – in the elaborated cal implications. Even viewed with the The telescope helped to bring the Moon
version of the medieval scholastics – by a naked eye, the Moon has brighter and (and the heavens) down to Earth, and
nesting set of concentric spheres, each darker areas – hence the ‘face’ in the Moon. demanded the same unified physics for the
containing one of the seven planets, starting As Galileo himself remarked, therefore, “if celestial and earthly realms. Without that
with the Moon. Everything below the sphere anyone should wished to revive the old unity, Newton’s universal mechanics and
of the Moon, everything ‘earthly’, was Pythagorean opinion that the moon is like gravitation would have been unthinkable.
subject to change, growth, decay. Everything another Earth, its brighter part might very Plotting a trajectory to the Moon would
in the sphere of the Moon or above was, on fitly represent the surface of the land and its have been inconceivable outside the myths
the contrary, perfect and unchanging. All darker region that of the water”. of Orpheus and the poetry of Dante. Such
celestial bodies had to move in perfectly Galileo himself was non-committal, but a journey would have crossed the boundary
circular orbits, and had to be perfectly in the minds of many readers this promptly between the mortal world of man and the
spherical. This included the Moon. suggested plants and animals, and maybe eternal world of spirit. Without Galileo’s
Galileo’s telescopic observations and rational, even human, inhabitants. But, as telescope to make the Moon into another
arguments for the ‘ruggedness’ of the Moon Galileo’s ecclesiastical friend Giovanni Earth, the Apollo astronauts could never
directly challenged this key Aristotelian doc- Ciampoli (c1590– 1643) reminded him, this have set off.
trine. Some academic philosophers – such as was no idle speculation, for it raised the
Galileo’s own colleague (and drinking question “how these [human inhabitants] Christopher Lewis is an affiliated scholar in the
companion) at Padua, Cesare Cremonini can be descended from Adam, or how they department of history and philosophy of science
(1550–1631) – simply declined to look can have come off Noah’s ark, and many at Cambridge University, studying the life and
through the telescope. Others sought to other extravagances you never dreamed times of Galileo

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