PHYSICAL SCIENCE

Viewpoint: Yes, atoms are real, and science has developed to the point that atoms can not only be seen, but can also be individually manipulated.

Viewpoint: No, many pre-twentieth-century scientists, lacking any direct evidence of the existence of atoms, concluded that atoms are not real.

At the start of his Lectures in Physics, the 1965 Nobel Laureate in Physics Richard Feynman asks what one piece of scientific knowledge the human race ought to try to preserve for future generations if all the other knowledge were to be destroyed in some inevitable cataclysm. His answer that the single most important scientific fact is that all matter is composed of atoms, now seems completely reasonable. How is it then, that less than 100 years before, the very existence of atoms could be disputed with some vehemence?

Although the notion of atoms has...