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Quite a few educated men in Song times took an interest
in matters related to ,
as well as .
One high official, , is famous for having designed
and constructed a mechanical clock tower (almost
40 feet high) by adding a chain-driven mechanism to the existing
water-powered clock. The clock told not only the time of day but also
the day of the month, the phase of the moon, and the position of certain
stars and planets in the sky. At the top was a mechanically rotated
armillary sphere that showed the changing location of the planets and
stars.
Another notable polymath of the time was , who
made contributions in fields as diverse as mathematics, geography, economics,
engineering, medicine, divination, archaeology, military strategy, and
diplomacy. In his writings Shen Gua described the use of petroleum and explained
in detail how Bi Sheng first made movable type from clay. He often analyzed
issues mathematically, and once computed the total number of possible
situations on a game board, and another time the longest possible military
campaign given the limits of human carriers who had to carry their own
food as well as food for the soldiers.
Shen Gua is especially known for the explanations of natural phenomena
found in his famous 11th-century book, Meng Xi Bi Tan (Meng
Ch’i Pi T’an or “Brush Talk from a Dream Book”; more
commonly known as the “Dream Pool Essays”).
In these pages he presents his theories on a variety of topics, including
the from due south:
When the point of a needle is rubbed
with the lodestone, then the sharp end always points south, but some
needles point to the north. I supposed that the natures of the stones
are not all alike. Just so, at the summer solstice the deer shed their
horns, and at the winter solstice the elks do so. Since the south and
the north are two opposites, there must be a fundamental difference
between them. This has not yet been investigated deeply enough. (1)
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Because the European “Scientific
Revolution” of the 16th and 17th centuries is generally
regarded as the foundation of the modern sciences and
because in the late 19th and 20th centuries China lagged
behind the most developed areas of Europe both economically
and technologically, it is too
commonly assumed that there was something about
Chinese culture or Confucian thought that was incompatible
with scientific inquiry and experimentation.
But as Joseph Needham notes in his Science and Civilisation
in China, China was for a time well ahead of the West
in the development of several fields of knowledge about the
physical world — including magnetism and optics — and
Chinese advances in engineering were, at least until 1500, “frequently
superior to anything which Europe could show.” (5) |
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In another chapter he identifies and from its existence argues that the region where it was found must have been much warmer and more humid in ancient times:
In recent years [c. 1080]
there was a landslide on the bank of a large river in Yung-Ning Kuan
near Yenchow. The bank collapsed, opening a space of several dozens
of feet, and under the ground a forest of bamboo shoots was thus revealed.
It contained several hundred bamboos with their roots and trunks all
complete, and all turned to stone. ... Now bamboos do not grow in Yenchow.
These were several dozens of feet below the present surface of the
ground, and we do not know in what dynasty they could possibly have
grown. Perhaps in very ancient times the climate was different so that
the place was low, damp, gloomy, and suitable for bamboos. ... (2)
In another place Shen Gua argues against the theory that are caused by the rising and setting of the sun and
demonstrates that they correlate rather with the cycles of the moon:
Lu Chao says that the tide of the sea is
formed because it is stirred up by the rising and setting of the sun.
This has not the slightest basis. If the tide were due to this cause
it would have a diurnal regularity. How could it happen that it sometimes
comes in the morning and sometimes in the evening?
I have myself given much study to
its periodic motion, and found that the tide comes to high water whenever
the moon makes its meridian transit. if you wait for this moment you
will never miss the tides. ... (3)
To explain his theory about why , not flat, Shen Gua wrote:
The Director asked me about the
shapes of the sun and moon; whether they were like balls or (flat)
fans. If they were like balls they would surely obstruct (ai)
each other when they met. I replied that these celestial bodies were
certainly like balls. How do we know this? By the waxing and waning
(ying
khuei) of the moon. The moon itself gives forth no light, but is
like a ball of silver; the light is the light of the sun (reflected).
When the brightness is first seen, the sun (-light passes almost) alongside,
so the side only is illuminated and looks like a crescent. When the
sun gradually gets further away, the light shines slanting, and the
moon is full, round like a bullet. If half of a sphere is covered with
(white) powder and looked at from the side, the covered part will look
like a crescent; if looked at from the front, it will appear round.
Thus we know that the celestial bodies are spherical. (4)
Shen Gua did not, however, realize that the sun and moon
had entirely different orbits and, later in this same passage, explained
that “they could meet without obstructing one another” because
they were both made of qi (vital energy) and “(have) form
but no solid substance.”
(1) Joseph Needham, Science and Civilisation
in China, Vol.
IV. Physics and Physical Technology, Part 1. Physics (Cambridge: Cambridge
University Press, 1962), 250.
(2) Joseph Needham, Science and Civilisation in China, Vol. III.
Mathematics and the Sciences of the Heavens and Earth (Cambridge: Cambridge
University Press, 1959), 614.
(3) Ibid., 492.
(4) Ibid., 415.
(5) Joseph Needham, Science and Civilisation in China, Vol. IV.
Physics and Physical Technology, Part 1. Physics (Cambridge: Cambridge
University Press, 1962), 2.
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