What’s the Matter?

Abstract

What is matter anyway? Really. In the fifth century B.C., a Greek—Democritus, by name—argued on philosophical grounds that one could not indefinitely subdivide matter into smaller and smaller bits. He expected that on cutting matter into finer and finer pieces, eventually one would come to a bit of matter that could not be cut. In his view, there existed tiny fundamental building blocks or particles, which could not be divided any finer and from which all other matter is constructed. These fundamental entities came to be called atoms, from a Greek word meaning uncuttable. Of course, Democritus had no means of testing his conjecture experimentally. Such evidence did not come until the early nineteenth century with the work of Lavoisier, Proust, and Dalton.*