Early Theories of Matter

In ancient Greece, philosophers debated the nature of matter. The philosopher Democritus held that matter was composed of elementary particles, called atoms, in otherwise empty space. Over two thousand years would pass before the existence of the atoms was proven. 

Science as we know it today did not exist several thousand years ago. No one knew what a controlled experiment was, and there were few tools for scientific exploration. In this setting, the power of mind and intellectual thought were considered the primary avenues to the truth. Curiosity sparked the interest of scholarly thinkers known as philosophers who considered the many mysteries of life. As they speculated about the nature of matter, many of the philosophers formulated explanations based on their own life experiences. 

Many Greek philosophers thought matter was formed of air, earth, fire, and water. They also associated properties with each of the four basic components of matter. The pairings of opposite properties, such as hot and cold, and wet and dry, mirrored the symmetry and balance the philosophers observed in nature. These early nonscien-tific and incorrect beliefs were not completely dispelled until the 1800s. 

The Greek philosopher Democritus (460-370 b.c.) proposed the concept of the atom more than two thousand years ago. 

Matter is composed of empty space through which atoms move. 

Different kinds of atoms have different sizes and shapes. 

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BCE Early theory of matter proposed by Greek philosopher... 

Philosophical" or theoretical chemistry was wide-ranging during most of the nineteenth century. In contrast, late-nineteenth-century physical chemists and twentieth-century physicists tended to narrow the definition of theoretical chemistry, eliminating organic structure theory and making theoretical chemistry almost exclusively physical and mathematical. An early indicator of this trend is Noyes s deletion of structure theory from the course in theoretical chemistry at MIT. A later indicator is the special issue of Chemical Reviews in 1991 which carries the title, "Theoretical Chemistry," and begins with an introductory editorial entitled simply "Quantum Theory of Matter." 5... 

S. Clucas, The infinite variety of forms and magnitudes 16th and 17" -cen-tury English corpuscular philosophy and Aristotelian theories of matter and form , Early Sci. Med., 1997, 2, 251-271. 

Boyle, Robert. (1627-1691). A native of Ireland, Boyle devoted his life to experiments in what was then called natural philosophy, i.e., physical science. He was influenced early by Galileo. His interest aroused by a pump that had just been invented, Boyle studied the properties of air, on which he wrote a treatise (1660). Soon thereafter, he stated the famous law that bears his name (see following entry). Boyle s group of scientific enthusiasts was known as the invisible college , and in 1663 it became the Royal Society of London. Boyle was one of the first to apply the principle that Francis Bacon had described as the new method —namely, inductive experimentation as opposed to the deductive method of Aristotle—and this became and has remained the cornerstone of scientific research. Boyle also investigated hydrostatics, desalination of seawater, crystals, electricity, etc. He approached but never quite stated the atomic theory of matter however, he did distinguish between compounds and mixtures and conceived the idea of particles becoming associated to form molecules. 

After establishing chemistry on its modern course following the demise of the phlogistic theory of matter, chemists of the late eighteenth century and early nineteenth century turned their attention to formulating laws and theories governing chemical reactions. Some of these laws and theories are briefly outlined below. 

The atomic theory of matter, which was conjectured on qualitative empirical grounds as early as the sixth century BC, was shown to be consistent with increasing experimental and theoretical developments since the seventeenth century AD, and definitely proven by the quantitative explanation of the Brownian motion by Einstein and Perrin early in the twentieth century [1], It then took no more than a century between the first measurements of the electron properties in 1896 and of the proton properties in 1919 and the explosion of the number of so-called elementary particles - and their antiparticles - observed in modern accelerators to several hundred (most of which are very short lived and some, not even isolated). Today, the standard model assumes all particles to be built from three groups of four basic fermions - some endowed with exotic characteristics - interacting through four basic forces mediated by bosons - usually with zero charge and mass and with integer spin [2],... 

Max Planck thought otherwise. He doubted that atoms existed at all, as did many of his colleagues—the particulate theory of matter was an English invention more than a Continental, and its faintly Britannic odor made it repulsive to the xenophobic German nose—but if atoms did exist he was sure they could not be mechanical It is of paramount importance, he confessed in his Scient c Autobiography, that the outside world is something independent from man, something absolute, and the quest for laws which apply to this absolute appeared to me as the most sublime scientific pursuit in life. Of all the laws of physics, Planck believed that the thermodynamic laws applied most basically to the independent outside world that his need for an absolute required. He saw early that purely mechanical atoms violated the second law of thermodynamics. His choice was clear. 

The Bohr Model Was an Early Attempt To Formulate a Quantum Theory of Matter 83... 

Once the Epicureans had suggested a reasonable explanation for a natural phenomenon, they took their enquiry no further. They were content to show that there was no need to involve any Deities (who might have to be propitiated). They were not troubled if two or more explanations could be advanced for a particular phenomenon, and they made no attempt to decide between such alternative theories. An account of Epicurean philosophy was given by the Roman Lucretius (c. 100-55 BC) in his poem De Rerum Natura. It was through Lucretius s work that Pierre Gassendi (1592-1655, Chapter 3) learnt of the Epicurean philosophy and became an early European advocate of the atomic theory of matter. 

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