A Brief and Eccentric History of Science

This history focuses on what we would today think of as astronomy and physics since it was the Scientific Revolution in astronomy and physics that led to modern science. Related changes took place in chemistry, biology, geology, and other areas, and some of those changes were initiated by the same people, but for the most part those changes took place later. The changes in world view and methods of acquiring knowledge were primarily cemented as a result of changes in astronomy and physics.

Antiquity

Zeno (450 B.C.E.)

Zeno raised problems about time and motion that lead to the question, "How can anything move, since at each moment, it is at a fixed location?"

Aristotle (350 B.C.E.)

Everything is like biology. Trees have a natural desire or tendency or need to grow upward toward the light. You can force them to grow other ways by trimming, tying, and so forth, but that goes against the natural purpose of their motion.

Everything is like that. There are five elements. The first four, earth, air, fire, and water are found on earth, and the fifth, aether, is what the heavens are made of. Each element has a natural motion.

That means that if we want to learn about the natural world, observation is important but experiment is a waste of time, since it reveals only forced, not natural motion.

Invented a formal system of deductive logic.

Theory of vision: Includes that each object puts out little "replicas" of itself, and our eyes receive those.

Euclid (300 B.C.E.)

Euclid developed an axiomatic, atemporal, three-dimensional theory of geometry, in part, it seems, to show that one could give a theory of space that does not fall into problems of the sort raised by Zeno. The transitions from axioms to theorems of geometry came to be seen as not themselves involving geometry, but only logic.

Ptolemy (100 C.E.)

Earth is at the center of the universe, everything else revolves around it in a complex system of interlocking spheres. The spheres make sounds and they have points of light on them.

Scholasticism

Aquinas (1250 C.E.)

Part of what he did was produce a synthesis of Christianity with Ptolemy and Aristotle.

Duns Scotus (1300 C.E.)

As the subtle doctor's views became displaced in the early Renaissance and his followers resisted, his name Duns became Dunce.

Scientific Revolution

Copernicus (1500 C.E.)

Copernicus was hired by the Church to devise a better calendar. In the process of devising a better computational method for predicting the motions of the planets–including the sun, Copernicus discovered that he could simplify the mathematics in an important way by putting the sun at the center, with the earth moving around it. He came to believe that that was actually the case. He kept quiet. His work was published when he was on his deathbed. He only saw a printed copy (1543) on the day before his death. Why?

The picture of the heavens given by Copernicus's theory was no simpler than that of Ptolemy's theory, and it is not clear that the Copernican theory was any more accurate in predicting the motions of the planets. The theory seemed obviously false, since it seems obvious that the earth beneath our feet isn't moving rapidly.

Osiander (1500 C.E.)

Osiander wrote the preface to Copernicus's book, suggesting that the idea that the sun is in the middle is only a computational convenience, an instrument to be used for predictive purposes. That was an influential expression of instrumentalism, the idea that theories are predictive tools, instruments, that need not (should not, do not, cannot—there are many variants) "describe the hidden structure of nature" (15).

Vesalius (1543 C.E.)

Discovered that the function of the heart is to pump blood around the body. Before, it was "the seat of the emotions." He was the first to do detailed dissections of human bodies, and corrected the old views of human anatomy based on animal dissections. This is here just to point out that there were other things going on besides astronomy and physics.

Tycho Brahe (1570 C.E.)

He was not a Copernican, though a lot of his theoretical work was developed under the influence of Copernican ideas. He developed an astronomical theory that was almost identical to that of Copernicus except that the earth was at the center of the universe. He preferred it because if the earth moves, then we should see an apparent motion of the stars. That is not the important work for which he is remembered (though it became the official theory of the Catholic church when Galileo's observation of the phases of Venus made the Ptolemaic theory untenable): he made the first systematic astronomical observations, and developed accurate techniques of observation. (That is the kind of thing that makes empiricists happy.) His work led to the idea of "the personal equation," which one still hears used as a metaphor from time to time. Kepler worked as his assistant in the last year of his life.

Kepler (1596 C.E.)

Kepler was a sun worshipper. First published defense of Copernicanism. He inherited Tycho's data. Orbits are ellipses, speed depends on distance from the sun, phenomenal accuracy.

Bruno (1600 C.E.)

Bruno was burned at the stake in 1600 for heresy, in part for proposing that there could be other inhabited worlds.

Galileo (1610 C.E.)

Galileo strongly supported the literal truth of the Copernican picture, used a telescope to make astronomical observations, including the phases of Venus, and developed the beginnings of a physical theory that is compatible with Copernicanism (natural motions in circles). He performed some of the first experiments concerning how motion works, and wrote humorously, belittling the Scholastics who relied on theology, not observation, for how things move. He also invented the pendulum clock. He was an effective advocate for the need of using mathematics in science. He spent his later years under house arrest for heresy.

Descartes (1610 C.E.)

He invented graph paper (not really—though for all I know, he did). He advocated MECHANISM--everything is like clockwork. He was also an extremely important philosopher (rationalist), but that is a topic for a different lecture.

Robert Boyle (1660 C.E.)

Program of systematic research (including, for example, the vacuum pump). One of the founders of the Royal Society, an early, extremely influential, organized community of scientists with the beginning of things like scientific journals, refereed reports, and specialized meetings. He was an alchemist, one of the founders of scientific chemistry, and the discover of Boyle's law.

Newton (1687 C.E.)

Newton finished the job: He gave a simple set of laws that account for Galileo's laws of how things move on the surface of the earth and Kepler's laws of how things move in the sky. His theory slightly modifies the predictions of the other theories and improves them. FOR THE FIRST TIME, THERE IS A SINGLE SET OF LAWS FOR THE EARTH AND THE HEAVENS. Both are of the same type.

He also worked out pretty much the modern theory of vision: light bounces off of things, is focused by a lense on the back of your eye. Thus what we see involves two rather distorted and funny shaped partial images of light reflected off of stuff.

He wrote more on religion than science, including an influential work on the length of the cubit, he investigated the bible and ancient temples for hidden messages, he invented the modern system of casting astrological horoscopes, and did extensive research in alchemy. Much of that other work went unpublished. Alchemy, in particular, was illegal. He would only sleep in a bedroom painted red, because, I believe of the astral vibrations.

He also invented methods of preventing the counterfeiting of coins. He also went undercover to investigate counterfeiters, and acted as a justice of the peace, leading to the execution of numerous counterfeiters.

His physical theory began a period of well over 200 years of just working out the details.

Aftermath

Frege (1880)

Frege devised a new system of formal logic, one that is powerful enough to capture all the deductive reasoning used by mathematicians and powerful enough that many people think it can capture all the deductive reasoning used by scientists.

Einstein (1905)

Special relativity. We all know that speed is relative to who is measuring it. Einstein managed to convince everyone that distance and time are also relative to the observer, the one making the measurement. He did so by telling an operationalist story of how one might measure distances and times using only mirrors and flashlights—he gave all the terms in his theory definitions in terms of what could be observed.

General relativity. Space itself is curved, and that means that light doesn't travel in straight lines.

-- ShaughanLavine - 29 Aug 2005 - 22 Aug 2007 - 27 Aug 2007