Greek atomists

Bailey, Cyril (1928), The Greek Atomists and Epicurus A Study, Clarendon Oxford. 

In Cyril Bailey The Greek Atomists and Epicurus Chapter III, Section 3 (p. 136)... 

Little is known about Titus Lucretius Cams beyond what can be gathered from his poem De rerum natura. He was born in about 95 B.C.E., but the exact date is uncertain. The exact date and circumstances of his death are also uncertain, but he probably died in or before the year 55 B.C.E. We do know from his poem that he believed the teachings of the Greek atomists, ranging from those of Democritus of Abdera (ca. 460 B.c.E.-ca. 362 B.C.E.) to those of Epicums (ca. 341 B.C.E.-270 b.c.e.). Unlike the writings of Democritus or Epicums, Lucretius s poem was one of the few literary works not lost to European peoples after the collapse of the classical world. 

Furley, 1967] D. J. Furley. Two Studies in the Greek Atomists, Princeton, 1967. 

In summary, for Leukipp and Demokrit, the empty space between the atoms was a key assumption in their model, because, if particles were closely packed, they could not move and substances could not be mixed. When asking students to philosophise about the nature of matter, we indeed find parallels to the ancient Greek thinking, both to the so-called atomists and to the continuous ideas of Aristotle and others. For example, Leukipp s and Demokrit s explanation for the specific weight of substances corresponds to one student conception younger students especially tend to explain differences in the specific weight (but also hardness of substances) with differences in the closeness of particles (Fig. 10.6). They seldom take into account that the particles could have a different weight themselves. 

Leopold May goes back even further in time to outline a variety of atomistic ideas from aronnd the world. His chapter Atomism before Dalton concentrates on conceptions of matter that are more philosophical or religiotts than scientific, ranging from ancient Hindu, to classical Greek, to alchemical notions, before touching on a few concepts from the period of early modem science. May is Professor of Chemistry, Emeritus, at the Catholic University of America in Washington, DC. 

Atomism did not die out altogether, however. The Greek philosopher Epicurus (c. 342-270 b.c.) made atomism part of his way of thought, and Epicureanism won many adherents in the next few centuries. One of these adherents was the Roman poet Titus Lucretius Cams (c.95-c.55 b.c.), usually known simply as Lucretius. He expounded the atomist viewpoint of Democritus and Epicums in a long poem entitled De Rerum Natura ( On the Nature of Things ). It is considered by many to be the finest didactic poem (one intended to teach) ever written. 

Boyle s experiments offered a focus for the gathering numbers of atomists. As I said earlier, Lucretius s poem, introduced in a printed edition (see page 28), had brought Greek views on atomism to the attention of European scholars. A French philosopher, Pierre Gassendi (1592-1655), was a convinced atomist as a result, and his writings impressed Boyle, who thereupon also became an atomist. 

Similarity is a fundamental notion that has been used, either implicitly or explicitly, throughout human history. While its exact beginnings are difficult to trace, the Greek philosophers most likely were responsible for early attempts to describe it in more formal terms. It was these same philosophers that also laid down some of the earliest, albeit simplistic, ideas on the nature of matter that formed the basis for the subsequent development many years hence of related theories in physics and chemistry. However, it was not until the nud-nineteenth century that theories describing the atomistic natnre of matter began to be developed in earnest. By the early part of the twentieth century many of the concepts of molecular stmcture and properties were well in hand and many novel applications of molecular similarity were developed. As computers... 

Leucippus (fl. 500 BCE) Greek philosopher who is said to have originated the atomistic theory that was taken up by Democritus and the poet Lucretius. 

Democritus (460-370 b.c.), for example, theorized that matter was ultimately composed of small, indivisible particles he called atomos or atoms, meaning not to cut. Democritus beiieved that if you divided matter into smaller and smaller pieces, you wouid eventuaiiy end up with tiny particles (atoms) that could not be divided any further. He is quoted as saying, Nothing exists except atoms and empty space everything else is opinion. Although Democritus was right by modern standards, most Greek thinkers rejected his atomistic viewpoint. 

Between 500 and 300 bce, the Greek philosophers Leucippus and Democritus formulated the ideas that the atomists held. Leucippus and Democritus believed that all atoms were essentially the same but that the properties of all substances arose from the unique characteristics of their atoms. For example, solids, such as most metals, were thought to have uneven, jagged atoms. Because the atoms were rough, they could stick together and form solids. Similarly, water was thought to have atoms with smooth surfaces, which would allow the atoms to flow past one another. Though atomists did not have the same ideas about matter that we have today, they did believe that atoms were constantly in motion, even in objects that appeared to be solid. 

Some Greek philosophers who studied matter between 700 and 300 bce described matter in a way that differed from the way atomists described it. They attempted to identify and describe a fundamental substance from which all other matter was formed. Thales of Miletus (640-546 bce) was among the first to suggest the existence of a basic element. He chose water, which exists as liquid, ice, and steam. He interpreted water s changeability to mean that water could transform into any other substance. Other philosophers suggested that the basic element was air or fire. Empedokles (ca. 490-ca. 430 bce) focused on four elements earth, air, fire, and water. He thought that these elements combined in various proportions to make all known matter. 

Greek philosophers viewed the physical world as matter organized in the form of bodies having length, breadth, and depth that could act and be acted upon. They also believed that these bodies made up a material continuum unpunctuated by voids. Within such a universe, they speculated about the creation and destruction of bodies, their causes, the essence they consisted of, and the purpose they existed for. Surfaces did not fit easily into these ancient pictures of the world, even those painted by the atomists, who admitted to the existence of voids. The problem of defining the boundary or limit of a body or between two adjacent bodies led Aristotle (fourth century BC) and others to deny that a surface has any substance. Given Aristotle s dominance in ancient philosophy, his view of surfaces persisted for many centuries, and may have delayed serious theoretical speculation about the nature of solid surfaces [2]. 

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