The ideas produced, while not scientific as we understand the term today, had within them remarkable insights, some of which appear to be true (or rather an accurate description for how the world appears to be organized.) This era gave birth to a new way to approach and explore natural phenomena, to gain understanding of their complexity and diversity in terms of natural explanations. It is worth considering that such a rational approach did not necessarily have to be productive - it could be that the world is really a totally irrational, erratic, and non-mechanistic place constantly manipulated by supernatural forces, but since science can’t address these kinds of ideas let’s just leave them to fantasy authors. The fact is that the assumption that the world is ruled solely by naturalistic forces has been remarkably productive.
The ancient Greeks developed complex ideas about the nature of the universe (and the matter from which it was composed) that were accepted for a long time. However, in response to more careful observation and experimental analysis, these ideas were eventually superseded by more rigorous theories. In large part this involved a process by which people took old ideas seriously, and tried to explain and manipulate the world based on them. When their observations and manipulations failed to produce the expected (or desired) outcomes, such as turning base metals into gold, curing diseases or evading death altogether, they were more or less forced to revise their ideas, often abandoning older ideas for ideas that "worked".
The development of atomic theories is intertwined with ideas about the fundamental nature of matter, not to mention the origin of the universe and its evolution. Most of the Greek Philosophers thought that matter was composed of some set of basic "elements", for example, the familiar Earth, Air, Fire, and Water. Some philosophers proposed the presence of a fifth element, known as quintessence or “aether”. These clearly inadequate ideas remain today as part of astrology and the signs of the Zodiac – a not particularly fitting tribute to some very serious thinkers.
The original elements (that is Earth, Air, Fire and Water) were thought to be composed of tiny indestructible particles – called atoms by Leucippus and Democritus (who lived around 460 BCE)[optional link]. The atoms of different elements where assumed to be of different sizes and shapes, and their shapes directly gave rise to the properties of the particular element. For example the atoms of earth were thought to be cubic; their close packing made “earth” difficult to move and solid. The idea that the structure of atoms determines the observable properties of the material is one that we will return to, in a somewhat different form, time and again, and while the particulars were not correct, the basic idea turns out to be sound.
In addition to their shapes, atoms were also thought to be in constant motion (based on watching the movement of dust motes in sunlight)[First description of Brownian motion - Epicurus], and that there was nothing or a “void” between them. Einstein's analysis of this type of motion, known as Brownian motion, provided strong experimental support for the physical reality of molecules (larger structures composed of atoms) and the relationship between molecular movement, temperature and energy (which we will consider later on in this chapter).
All in all the combined notions of the Greek philosophers provided a self-consistent and satisfactory basis for an explanation of the behavior of matter, as far as they could tell - or better put, all that they needed to know for their day to day purposes. The trap here is one that is very easy to fall into. That is: a satisfying explanation for a phenomenon does not necessarily mean that it is true. An explanation, even if it seems to be self-consistent and useful or comforting, is not scientific unless it makes testable quantitative predictions. For example: it was thought that different materials were made up of different proportions of the four ancient elements. Bones were made of water, earth and fire in the proportions 1:1:2, whereas flesh was composed of these elements in a ratio of 2:1:1.[from A History of Greek philosophy By William Keith Chambers Guthrie. p212.] Some philosophers even thought that the soul was composed of atoms or that atoms themselves had a form of consciousness, two ideas that seem quite foreign to (most of) us today. While these ideas are now considered preposterous (if not just silly), they contain a foreshadowing of the Law of Constant Proportions (which would come some 2300 years later and which we will deal with later in this chapter).
Such ideas about atoms and elements provided logical and rational (non-supernatural) explanations for many of the properties of matter. But Greeks weren’t the only ancient people to come up with explanations for the nature of matter and its behavior. In fact it is thought that the root of the words alchemy and chemistry is the ancient Greek word Khem, their name for Egypt, where alchemy/chemistry are thought to have originated.[optional link] Similar theories were being developed in India at about the same time, although it is the Greek ideas about atoms that were preserved and used by the people who eventually developed our modern atomic theories. With the passage of time, ancient ideas about atoms and matter were kept alive by historians and chroniclers, in particular scholars in the Arabic world.
As a seasoned expert in the history of scientific thought and the development of atomic theories, I can draw upon a wealth of knowledge to shed light on the concepts presented in the provided article. My understanding encompasses the intricate evolution of ideas, the challenges faced by early thinkers, and the pivotal moments that shaped our understanding of the natural world.
The passage reflects on the ancient Greek philosophers' contributions to the understanding of the universe and matter. The Greeks, such as Leucippus and Democritus around 460 BCE, proposed the concept of atoms—tiny, indivisible particles that composed the fundamental elements of Earth, Air, Fire, and Water. These elements were believed to have specific shapes, with, for example, earth having cubic-shaped atoms.
One notable aspect of Greek atomic theory was the acknowledgment of constant motion among atoms, a notion inspired by observations of dust motes in sunlight—an early description of Brownian motion attributed to Epicurus. The realization of constant atomic motion and the existence of void between atoms paved the way for later developments, including Einstein's analysis of Brownian motion, which provided experimental support for the physical reality of molecules and their connection to temperature and energy.
The Greeks' atomic theories provided a coherent and satisfactory basis for explaining the behavior of matter in their time. However, the article highlights the crucial distinction between a satisfying explanation and scientific truth. It emphasizes that a comprehensive and logical explanation, even if self-consistent and comforting, does not qualify as scientific unless it generates testable, quantitative predictions.
Furthermore, the article touches upon the Greeks' belief in the specific proportions of elements composing different materials, such as bones and flesh. While these ideas are now considered preposterous, they foreshadow the Law of Constant Proportions, a concept that emerged much later.
The passage also mentions that similar theories about the nature of matter were developed in India around the same time as the Greek philosophers. The roots of the words alchemy and chemistry are traced back to the ancient Greek word "Khem," their name for Egypt, where alchemy and chemistry are thought to have originated. The article suggests that while various ancient cultures contributed to the understanding of atoms and matter, it was the Greek ideas that were preserved and eventually used in the development of modern atomic theories.
Finally, the article acknowledges the role of historians and chroniclers in the Arabic world who kept alive ancient ideas about atoms and matter over time, contributing to the continuous evolution of scientific thought.
