Wednesday, April 10, 2013

History of Science -- Part One: Greek Science

We owe the philosophies of ancient Greece credit for setting the scene for science by seeing Nature as explainable. Prior to that, explanations of the natural world were all wrapped in gods and magic. When Aristotle’s writings were rediscovered, they were seen as the wisdom of a “Golden Age.” From the ancient Greek, via Arabic, and translated into Latin in the Middle Ages, beginning in the 12th and 13th centuries.

Aristotle noted that everything that happens, even the sprouting of acorns into oak trees, for example, is essentially the motion of matter. He therefore started by treating the motion of simple objects using a few fundamental principles. This is the way we do physics today, even though Aristotle got several ideas that were wrong. But Aristotle’s method of deriving fundamental principles was the correct method. Unfortunately, the Greeks did not favor experiment, and they assumed these fundamental physical properties could be intuitively perceived as self-evident truths.

Here are a couple of his errors. A material object sought rest with respect to the cosmic center, which “clearly” was Earth. An object fell because of its desire for the cosmic center. A heavy object, with its greater desire, would therefore, without doubt, fall faster than a light object. In the perfect heavens, on the other hand, heavenly objects moved in that most perfect of figures, the circle. These circles were on the “heavenly spheres” centered on the cosmic center, Earth.

Greek science had a fatal flaw. It had no mechanism to compel consensus. The Greeks saw tests of scientific conclusions no more necessary than were tests of politics or aesthetics. Conflicting views could be argued indefinitely.

Just through pure thought and philosophy, however, on occasion the Greeks came up with good science. The theory of atoms, and the name “atom” originated from a Greek Philosopher named Democritus who lived around 400 BC. He proposed that all life and matter is made up of tiny particles which he called atoms. The word “atom” comes from the Greek word “atomos” meaning indivisible.

Further, the pure thought and rules of logic did lead to the development of mathematics. But what separates mathematics from all the other sciences is experiment. The basis of modern science is on the results of experiments. Experiments that demonstrate the validity of theories and experiments suggested by theories and used to “prove” the theories correct.

To quote the Nobel Prize winning physicist, Richard Feynman, “It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong.” All science from physics to chemistry to biology is based on experimentation. Mathematics is unique in that regard because it is entirely based on axiomatic reasoning and proofs.

We do owe the Greek thinkers a great deal of gratitude for putting mathematics on an axiomatic basis. On occasion, their guesses and philosophies about physical science were correct or at least close. But they could be way off and mislead the advancement of science for hundreds of years of appeal to authority.

In general, the Greeks not only didn’t use experiments, they considered them below their station in life. Experiments were a form of manual labor and that was reserved for the common workman, while the scientists of the Greek age simply argued for the truth. There were some exceptions.

A very notable exception is Eratosthenes, a Greek who lived around 200 years before Christ. He was the first person to use the word "geography" in Greek and he invented the discipline of geography as we understand it. He invented a system of latitude and longitude and was the first person to calculate the circumference of the earth by using a measuring system using “stades,” or the length of stadiums during that time period with remarkable accuracy.

He was the first to calculate the tilt of the Earth’s axis (also with remarkable accuracy). He may also have accurately calculated the distance from the Earth to the Sun and invented the leap day. He also created the first map of the world incorporating parallels and meridians within his cartographic depictions based on the available geographical knowledge of the era. In addition, Eratosthenes was the founder of scientific chronology. He endeavored to fix the dates of the chief literary and political events from the conquest of Troy. He also proposed an algorithm for determining prime numbers that is still used today in computer programs that determine if a given number is prime.

His accomplishments and use of experiments, data, and mathematics would yield a Nobel Prize in today’s modern scientific culture and I’m always surprised how unknown he is compared with the other great Greek thinkers.

The thinkers of the Golden Age launched the scientific endeavor, but, without a method to establish agreement, progress was impossible. Though Aristotle established no consensus in his own day, in the late Middle Ages his views became the official dogma of the Church, mostly through the efforts of Thomas Aquinas.

Aquinas fitted Aristotle’s cosmology and physics together with the Church’s moral and spiritual doctrine to create a compelling synthesis. Earth, where things fell, was also the realm of morally “fallen” man. The heavens, where things moved in perfect circles, were the realm of God and His angles. At the lowest point in the universe, the center of the Earth, was Hell. When, at the beginning of the Renaissance, Dante used this cosmological scheme in his Divine Comedy, it became a view that profoundly influenced Western thought.

Yet the Greeks founded modern mathematics, discovered both magnetism and electricity, and set the world to ponder on the source and motive power of the celestial orbs.

Aristotle attributed the first of what could be called a scientific discussion on magnetism to Thales of Miletus. The term “magnet” comes from the name “Magnesia-on-the-Maeander,” an ancient Greek city where mysterious stones were found. They could attract or repel each other. We now know this mineral as Magnetite (Fe3O4).

And the term “Electricity” comes from the Latin word “electrum” and from the Greek “elektron.” Both words for the mineral "amber." If you rub amber with a wooly cloth, it will then attract small bits of paper with what is sometimes called “static electricity.”

So the ancient Greeks were right at the heart of the mysteries of physics, if not arriving at the correct solution. They studied gravity, magnetism, electric force, and the heavenly orb, as well as putting mathematics on a strong foundation and making advances in many other areas of science from medicine to botany and zoology. In fact, that search for the correct solution, the explanation of all in the physical realm, continues to this day and new discoveries are as fresh as today’s newspaper.

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