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Scientific
Method:
Galileo is the scientist who is credited with the development of the
method, and what he used it for nearly cost him his life. But the story begins
long before Galileo's time.
In the latter part of the sixteenth century Nicolaus Copernicus' book,
describing the movement of heavenly bodies, was published. Copernicus had worked
according to the scholastic method; he approached science by pure thought, not
by experimentation. Nearly fifteen hundred years before him an ancient Greek
named Ptolemy described the movements of the stars and planets, as they appeared
to an observer standing on the earth. Ptolemy's concept of the universe had the
earth at its center and the heavens revolving around it.
That this idea sprang from an ancient, "heathen" culture, there
is no doubt; but the concept proved to have much wider appeal. Having the earth,
the jewel in the crown of God's creation, at the center of the universe was a
comforting thought for Christians. The Roman church enthusiastically embraced
Ptolemy's model of the universe and defended it emphatically.
Copernicus may have approached nature in a traditional manner, but his
thoughts were far from the classical, earth-centered concept of the universe.
The Copernican view placed the Sun at the center of the heavens and had the
planets revolving around it. Suddenly, with Copernicus' model, the earth was
just another planet, no longer at the center of creation. The idea was certainly
at odds with the church, but Copernicus never tasted the wrath of Rome, for two
reasons. First, he died just when his book was published, in 1543; some say he
only saw a copy of it on his death bed. And, second, the church of Rome had
little to fear from Copernicus' work in 1543; that, however, would change.
Galileo saw the Copernican model of the heavens as an unproven idea. This
was an important new attitude to have about a thought, but it was a rather odd
way of responding at the time. Until Galileo, an explanation of nature was
correct only because it was the result of a logical thought process. If no rules
of logic were broken in arriving at a conclusion, that was proof enough of its
truth. In fact, such an intellectual proof was considered the only valid one.
That was the scholastic method which Copernicus followed. The thought of
physically testing an idea would not have occurred to anyone because it was not
logical, it made no sense whatsoever in Galileo's time. Pure thought could be
trusted because it came from within; but any observational data was considered
totally unreliable because it had to enter through the fallible human senses.
Nevertheless, Galileo considered Copernicus' model only as we consider an
hypothesis today. An hypothesis is a tentative conclusion, based on all the
available facts, but still having a relatively low level of certainty. The more
information (data) supporting an hypothesis, the more believable it becomes.
Finally, after considerable factual support is amassed, an hypothesis is
elevated to a theory. The general public gives the word theory a fairly low
level of credibility; a theory to most people is what a scientist uses the word
hypothesis to mean. But in science, theories are well supported, highly regarded
explanations of nature. As more support accumulates for a theory, it will
eventually gain the status of a principle or law.
Galileo took Copernicus' model of the universe as an hypothesis requiring
further support. He then went ahead to make observations to test the hypothesis,
he drew his conclusions about the validity of the hypothesis from his
observational data, and he published the results. It all seems to be a pe
rfectly normal way of doing things. "Check it out," "Take it for
a test drive," "Do a taste test": our everyday speech is rich
with examples of our commitment to testing things and ideas. We fully appreciate
the awesome power of experimenting and observing to verify our ideas; but its
power must have come as quite a shock when Galileo first delivered it in the
seventeenth century. It was especially shocking to the church, no doubt, for
Galileo's scientific method aimed its full power of persuasion directly at one
of the church's central beliefs. After reading Galileo's work, no reasonable
person would have been able to logically accept Ptolemy's model.
This was a bad time to be questioning even the most trivial point of
religious dogma. It was the time when the Roman church was responding to Martin
Luther and the Reformation. This was the Counter Reformation, a time when any
questions of faith were viewed as heresies and when any challenge to the
church's authority had to be crushed. It did not matter that the geocentric (earth centered) system was a heathen belief right from the start, the Roman church could not permit Galileo to challenge its authority. Perhaps if the new scientific method were not quite so convincing, and perhaps if Galileo were not quite such a celebrity, then perhaps the church would not have had to be so unrelenting in its pursuit of him; but it was. It had no real choice given the circumstances of the time. Galileo was arrested, tried, and convicted of heresy when he was seventy years old. But the Copernican model lived on to become a principle of astronomy, and the scientific method is still used today in much the same way that Galileo used it more than three hundred years ago.
©
M.W. Caprio |