Atoms ancient Greek ideas

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. 

The idea that matter is made up of atoms was not new in Dalton s time. It was known to the ancient Greeks. Even in Robert Boyle s day the idea that matter was composed of particles, or corpuscles, of some kind was commonly believed. Dalton revolutionized chemistry, not by reintroducing this old idea but by formulating a workable theory of the formation of chemical compounds. 

People have been thinking about tiny objects for a long time. The ancient Greek philosopher Democritus (ca. 460-370 b.c.e.) believed that properties of matter depended on the shapes of small, indivisible bits of matter called atoms. Although this idea failed to catch on at the time— no one could see these atoms because they were so small—in 1803, the British chemist John Dalton (1766-1844) proposed a similar theory. Dalton s theory was an important advance and helped scientists understand chemical reactions—for example, the reaction of two atoms of hydrogen (H) and one atom of oxygen (O) to form H O—but atoms themselves remained cloaked in mystery. 

Al-Razi (Rhazes, 854-925) was a Persian who studied in Baghdad. Al-Razi wrote extensively on medicine, philosophy, astronomy, and alchemy, but he was primarily a physician. Al-Razi was less mystical than his contemporary alchemists and classified chemicals by their origin. According to Al-Razi, chemicals came from either animals, plants, and minerals or were derived from other chemicals. Al-Razi wrote The Comprehensive Book, which was an enormous medical encyclopedia that synthesized medical practices of ancient Greeks, Syrians, Arabs, and Persians. Al-Razi was the first person known to describe the disease smallpox. Most of his alchemical writings have been lost, but Al-Razi believed in the atomic nature of matter. Al-Razi took a systematic approach to science and rejected the idea of divine intervention. His rational methods and descriptions were more consistent with modern science than most individuals of his time. Ali al Husayn ibn Sina (Avicenna, 980-1037) was another Persian physician whose voluminous works, including The... 

Atom The word comes originally from the Greek word atomos, meaning uncut or indivisible. The ancient Greek philosophers known as the Epicureans believed that matter was composed on small, hard particles they called atomos. The idea and the word was revived in the 1600s to represent the smallest fundamental particle of matter. Today it means the smallest part of an element that can exist independently and interact chemically. 

The third and final Greek contribution that we shall mention here is the notion of classification. The ancient Greeks were classifiers par excellence and classified everything from atoms to animals. In fact it was Aristotle who first attempted a classification of the various species of fauna [7]. The process of classification always involves the idea of similarity in this process objects that have at least some features in common, i.e. some similarity, are grouped together to form classes or categories. The process was explored in some detail in a book... 

The ancient Greek philosophers Leucippus and Democritus beheved that atoms existed, but they had no idea as to their nature. Centuries later, in 1803, the English chemist John Dalton, guided by the experimental fact that chemical elements cannot be decomposed chemically, was led to formulate his atomic theory. Dalton s atomic theory was based on the assumption that atoms are tiny indivisible entities, with each chemical element consisting of its own characteristic atoms. ... 

Our current tuiderstanding of the nature of atoms has evolved from the ancient, untested ideas of Greek philosophers, partly as a result of modern technology that has produced images of atoms. 

With that caveat, what do we know about molecules and how do we know it We begin with the idea that organic compounds and all other substances are composed of atoms—indivisible particles which are the smallest units of that particular kind of matter that still retain all its properties. It is an idea whose origin can be traced to ancient Greek philosophers. Moreover, it is convenient to correlate our observation that substances combine only in certain proportions with the notion that these submicroscopic entities called atoms combine with each other only in certain ways. 

The idea of atoms has been around since the time of the ancient Greeks. 

Why were Dalton s ideas about atoms considered a scientific theory, whereas the ideas of ancient Greek philosophers... 

Einstein s theory of Brownian motion was ground-breaking because it substantiated the atomic hypothesis, or the Atoms Doctrine, as Perrin calls it in his wonderful book. First enunciated by the ancient Greeks, the idea that all matter consists of minute, indivisible entities called atoms became a sound scientific hypothesis with the work of Dalton, Boltzmann, and Mendeleyev. But it was not until Einstein worked on the... 

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. 

Then came the Renaissance, a period of the recovery of ancient learning and of an unstoppable flow of new observations and new ideas, often emerging from or inspired by the old. Lucretius was rediscovered, and so was Epicurus. Greek atomism became fashionable at the French court. But just as Aristotle in the twelfth and thirteenth centuries had had to be interpreted and modified so as to be reconciled with Christianity, so too did atomism in the seventeenth century. Gassendi undertook the Christianization of atomism. Atoms, he explained, were not eternal but created by God. Their movement in the void was not random but the result of their God-given initial motions, which made them agents of divine purpose. 

The idea of atoms, which has similarities with modern ideas, is thus ancient. However during that time, it was pure speculation just like any other Greek theory and did not make any special impact. 

While many civilizations learned how to make dyes and pigments, or ferment fruit into wine, the earliest theories about atoms and what makes up the chemical world came from ancient Greece and India. Leucippus in Greece and Kanada in India both came up with the idea that there must be a small, indivisible part of matter. The Greek word for uncuttable is atomos, clearly the root of the modern term atom. Kanada s term for this similar concept was paramanu or simply anu, the indivisible element of matter. 

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