JACK'S WINNING WORDS 12/12/06
“Nothing exists except atoms and empty space. Everything else is opinion.” (Democritus) I agree with this one, but that’s just a matter of opinion. Democritus was called “the laughing philosopher,” because he was always laughing. Some said that he was mad, but others said he just had a happy disposition. Do some laughing today, but watch out for those who might call you, mad! Democritus was a pre-Socratic thinker, born in 460 BC. ;-) Jack

FRIEND L. P. WRITES: This seems like a pretty advanced thought for 400BC! It reminds me of my undergrad days in chemistry and physics. Though I must say that thinking on the level of atoms and empty space makes my skin crawl a bit. I start to wonder how I stay disjoint from the furniture on which I'm sitting. Though in the context of biochemistry and multicellular organisms it puts an added layer of "awe" to the miracle of life. Speaking of miracles, faith, and science... have you seen the recent book by Francis Collins? I saw a short interview he gave on it the other day but have not looked at the book myself.

A HISTORY AND PHYSICS LESSON:
Evolution of the Atomic Concept and the Beginnings of Modern Chemistry
Michael Fowler
University of Virginia Physics 252 Home PageLink to Previous Lecture
Early Greek Ideas
The first "atomic theorists" we have any record of were two fifth-century BC Greeks, Leucippus of Miletus (a town now in Turkey) and Democritus of Abdera. Their theories were naturally more philosophical than experimental in origin. The basic idea was that if you could look at matter on smaller and smaller scales (which they of course couldn't) ultimately you would see individual atoms - objects that could not be divided further (that was the definition of atom). Everything was made up of these atoms, which moved around in a void (a vacuum). The different physical properties -- color, taste, and so on -- of materials came about because atoms in them had different shapes and/or arrangements and orientations with respect to each other.
This was all pure conjecture, but the physical pictures they described sometimes seem uncannily accurate. For example, here is a quote from Lucretius, a contemporary of Julius Caesar, on the ideas of Epicurus, who was a follower of Democritus:
…look closely, whenever rays are let in and pour the sun's light through the dark places in houses … you will see many particles there stirred by unseen blows change their course and turn back, driven backwards on their path, now this way, now that, in every direction everywhere. You may know that this shifting movement comes to them all from the atoms*. For first the atoms of things move of themselves; then those bodies which are formed of a tiny union, and are, as it were, nearest to the powers of the atoms, are smitten and stirred by their unseen blows, and they, in their turn, rouse up bodies a little larger. And so the movement passes upwards from the atoms, and little by little comes forth to our senses, so that those bodies move too, which we can descry in the sun's light; yet it is not clearly seen by what blows they do it.
(*called "first-beginnings" by Lucretius - we'll put "atoms", he meant the same thing.)
Is it possible some young Greeks had acute enough eyesight to see Brownian motion?
These Greek philosophers believed that atoms were in constant motion, and always had been, at least in gases and liquids. Sometimes, however, as a result of their close-locking shapes, they joined in close-packed unions, forming materials such as rock or iron. Basically, Democritus and his followers had a very mechanical picture of the universe. They thought all natural phenomena could in principle be understood in terms of interacting, usually moving, atoms. This left no room for gods to intervene. Their atomic picture included the mind and even the soul, which therefore did not survive death. This was in fact a cheerful alternative to the popular religions of the day, in which the gods constantly intervened, often in unpleasant ways, and death was to be dreaded because punishments would surely follow.
Little conceptual progress in atomic theory was made over the next two thousand years, in large part because Aristotle discredited it, and his views held sway through the Middle Ages

FROM DAZ: That may all be true, but as I recall my introduction to atomic and molecular theory, Neils Bohr came up with the modern concept and the word atom was an old old word he and others adopted because it had been used to describe the smallest things, building blocks of matter, or something like that. When I saw atom in your thing I was going to question it, but then I remembered the preceding. Not as elegant as what the professor came up with, but---