Breakthroughs in Astronomy and Medicine in the 16th and 17th Centuries
It was during the 16th and 17th centuries when man's view of the unvierse and himself
changed drastically. This came after a millenium of repetition and stagnation in the
development of science. People finally began questioning what they were told, and they
went out to find proof rather than assuming on the basis of authority and common sense.
These advances in astronomy and medicine came about in the same era, and were not
unparallel in their development. In both fields were some very notable people who
contributed greatly to the devolopment in these areas. In the field of astronomy
Copernicus, Brahe, Kepler, and Galileo shed Aristotle's, Plato's, and Ptolemy's views of
the universe. In medicine Paraclesus, Vesalius, and Harvey did away with Galen's
Ancient Greeks believed that the Earth was stationary, they concluded this by
making some basic obsevations. One being that the Earth cannot be part of the 'heavens'
because celestial bodies are bright points of light, whereas the Earth is a nonluminous
sphere of mud and rock. Also in the heavens there is very little change, the same stars are
there night after night, only five planets, the sun, and the moon. On Earth however things
are constantly changing and reforming. Their senses also told them that the Earth wasn't
moving. They believed that the air, the clouds, and the birds would all be left behind if
the Earth spinning around, therefore it couldn't be moving. Also if the Earth were
spinning everything would fly off due to the centrifugal force. It was thought that with
all this evidence there was no way that the Earth could be moving.
There were however a few descrepencies in this Earth stationary or geocentric
view. The most apparent being the five planets. They moved unlike anything else, they
moved contrary to the stars and occasionaly went backwards. Ptolemy was able to
correct this by the use of epicycles. This said that not only do planets orbit the Earth, but
they also have smaller circular moton which they perform during their orbit. This did
solve the problem, but it was still imperfect and very complicated, it was un-Godlike.
Nicolaus Copernicus believed in the heliocentric model of the universe. It was his
belief that the sun was a copy of God, God gave us life and the sun kept us alive. This
view was also a lot more aesthetically pleasing, although it was still not perfect. Most
other people only looked at his work as being a tool and not reality. This was because
when the book was published an introduction was added saying that the contents weren't
really true. Also people didn't observe any shift in the stars throughout the year, which
meant the world couldn't be moving around the sun because they should shift when
looked at from different sides of the sun. Unless of course they were really far away, but
that didn't make sense because God wouldn't waste that much space.
Tycho Brahe spent most of his life studying the movements of the celestial bodies.
His calculations led him to create a third view of the universe. He said that the planets
revolved around the sun, and the sun, moon, and stars revolve around the Earth. It had
the same flaws as Copernicus' model, but it didn't go against the church. When Tycho
died he gave all his calculations to Johaness Kepler. Kepler revised Copernicus's model
of a heliocentric universe. The big difference was that he said that the planets moved in
ellipses, with the sun at one focus. To account for the planets' motion he said that they
must move a variable speeds.
It was Galileo Galilei who came up with the 'proof' for a heliocentric universe. In
1609 he pointed a telescope into the sky. He saw four things which made the traditional
view of the universe wrong. He saw new stars which had never been seen before, which
disproved the idea of stars all being on one heavenly sphere. He saw that the Moon had
craters which proved that the Earth wasn't the only thing that decayed. The moons of
Jupiter hepled explain the Moon. The phases of Venus made the Ptolemaic model
immposible. The geocentric view had finally been disproven.
The Greek physician Galen did remarkable work in the field of human anatomy,
despite the fact that he could onyl dissect animals. His works were studied, and
considered the highest authority on anatomy. Anyone who studied medicine, studied
Paracelsus, a German physician, said that disease came from external sources. He
argued against the work of Galen and against the church. He, like Copernicus, went
against the norm, and preeched what he believed.
It was Andreas Vesalius who first went against Galen anatomy. He wrote De
humani corporis fabrica, an illustrated book which included information he had gathered
from performing his own disections. Tycho Brahe who spent his life collecting data,
Vesalius collected the information for himself too.
William Harvey was able to prove that blood circulated through the body. He also
said that the heart was a pump, rather than a heat generating organ. He published On the
Motions of the Heart and Blood, which disproved the classic belief of the 'pneuma'
physiology. Much like Galileo who gave the proof for the heliocentric world, he gave the
proof for the modern view of the human body.
These ideas changed the world forever. "The Great Interuption," as Daniel
Boorstin puts it in The Discovers, was finally over. Man had stopped believing
everything that it was told, and had gone out to prove it for himself. The human body
and the universe were never looked at the same way again. It only took a few smart
people, who willing to speak out, to change the world