2,637 YEARS OF
PHYSICS
FROM THALES OF MILETOS
TO THE MODERN ERA
SHELDON COHEN
Copyright 2017 Sheldon Cohen,
All rights reserved.
Published in eBook format by eBookIt.com
ISBN-13: 978-1-4566-2894-9
No part of this book may be reproduced in any form or by any electronic or mechanical means including information storage and retrieval systems, without permission in writing from the author. The only exception is by a reviewer, who may quote short excerpts in a review.
The author, Sheldon Cohen, is a retired physician with a lifetime fascination of Physics.
So, why not write a book?
Dedicated to
BETTY,
Gail, Paul,
Amanda, Shane, Megan, Travis, Carly, Alexa, Ethan, Emily,
Derek, Rylie, Benjamin.
ILYI
THE FIRST THOUGHT EXPERIMENT: IS THERE A PRIMORDIAL BUILDING BLOCK?
Once humankind developed the capability to contemplate who they were in relation to the world about them, some began to wonder if there was a similarity to all objects in the environment. It was easy to notice that the differences were visually vast, but could there be a common indivisible building block for all the great variety of animate and inanimate objects that were visible to our senses?
For instance, some of these thinkers wondered: if you were able to cut a gold bar in half, and then cut the half piece in half, and then cut the quarter piece in half, and then the eighth, and then the sixteenth, etcetera, when are you forced to stop; or will you ever reach that point? Is there a time in this process when you would end up with a fragment that could no longer be broken down into a smaller piece (the smallest possible piece still identifiable as gold)? The Greeks named this infinitesimally tiny end piece atomos (atom) meaning ‘unbreakable’ in the Greek language.
In this era, proof of the makeup of the microscopic world did not exist in the minds of man, so the level of the infinitesimally small could only be conjectured upon via mythological thought experiments. Thus it would remain for many centuries until the invention of the microscope opened up this realm to human view and slowly expanded thought.
Although the atomistic concept, devised strictly through the minds of human beings, was a brilliant thought experiment and portended great advances to come, there were still those who disputed this theory and felt that the animate and inanimate objects of the world were visually accessible and made of materials that were common to our senses. We could see these primary substances. Everything in our sight was visually accessible, and formed by combining together in a variety of amounts that made for almost infinite combinations. It would be this mythological thought that would remain supreme in the minds of man for the centuries it would take before a return to the atomistic concept and the rapid advances which would finally ensue in the minds of advanced thinkers. Who were these great pioneers of ancient times?
Thales of Miletos (624-546 BCE)
He is one of the first to attempt an evaluation about the above mentioned theory. He is recognized as the founder of ancient Greek philosophy and physics, Thales suggested that water was the most fundamental structure that led to all other things. His reasoning: the ability of water to become vapor and exhibit motion. According to the Greeks, this capacity for change and motion indicated life. Thales felt that our universe was a living organism directed by water as the primary substance.
As mentioned before Thales, explanations for any natural phenomena had always relied on mythology, an aspect of religion. Thales contribution to the advancement of human intellect was a first step in the evolution of thinking from myth to reason.
Thales became fascinated by the force of attraction between bodies and made a serious study of this phenomenon. Even primitive man undoubtedly recognized this attractive force, but no one ever studied the phenomenon with the intent of understanding what such attraction meant until Thales.
Miletos, on the Aegean Sea in an area that is now Turkey, was near a town known as Magnesia. Magnesia had abundant deposits of lodestone, a naturally occurring type of iron ore well known to attract iron but no other substance. Someone named this attractive force magnetism and a substance that had this property became a “magnet.” Thales appreciated this phenomenon and became fascinated, thus embarking upon a serious study in an attempt to understand what it meant.
As part of this study, Thales discovered that rubbing amber with cat fur caused the amber to attract light objects like feathers or straw in a manner similar to the iron ore. Clearly, this represented a mysterious attractive force, and the Greeks therefore believed that the amber had a ‘soul.’ They considered this force different from magnetism that only involved iron, because many substances also had the ability to attract other objects when rubbed. Why? The answer would be a long time coming as it would remain a mystery for 2500 years. This would prove to be a major scientific discovery from which great advances evolved; for this attractive force would, centuries later, come to be known as static electricity. Ancient man was good at discerning, but did not have the basis to explain what it was exactly that they had discerned.
Thales was forever steeped in study. Plato tells the story about Thales once falling into a well while focusing his attention on the stars above. A servant girl, who pulled him out, stated that he was so eager to know the stars that he paid no attention to what was under his feet. They wrote on his tomb: Here in a narrow tomb great Thales lies; yet his renown for wisdom reached the skies.
We will jump to three centuries later when another Greek philosopher,
Theophrastus (371-286 BCE)
determined that other substances when rubbed shared amber’s unusual attractive power. Could this represent a universal force shared by matter? The thinkers of the day wondered what this force was, but at that time they could not advance beyond what was only an interesting discussion.
Back to the fifth and sixth centuries BCE
Anaximander (610-546 BCE)
was one of Thales pupils who disputed Thale’s thesis. For his time, he realistically proposed his own thesis: he denied that the fundamental building block was anything of form and structure such as the water of Thale’s hypothesis, but rather permeated the world and was infinite and timeless and transformed itself into various forms of matter discernable by our senses. This suggested that the real unifying force was more mysterious than could be visualized and lay currently hidden and undiscovered. This was an intellectual way of saying, “we don’t know enough yet.”
Aniximander’s contribution was to suggest that theories based upon the reality of the world around us, and on our visual senses, were perhaps too primitive in terms of the understanding of the time to suggest any real unifying mechanism. More discoveries were necessary before a solid foundation evolved into factual theories. In the meantime, his suggestion of an infinite and timeless primordial building block was closer to the mark, but again would have a many centuries wait for clarification.
Anaximenes (570-528 BCE)
disputed both Thales and Anaximander, and suggested that air was the primary building block from which all else was created. Here we see another educated, for the times, wild guess. Anaximenes reasoned that since air was continuously in motion, it was life. In a state of even dispersal it presents itself as the