The strange world of the quantum
pp. 91-124
in: Alfred Tauber (ed), Science and the quest for reality, Berlin, Springer, 1997Abstract
The word "quantum' means "a quantity' or "a discrete amount'. On an everyday scale we are accustomed to the idea that the properties of an object such as its size, weight, colour, temperature, surface area, and motion are all qualities which can vary from one object to another in a smooth and continuous way. Apples, for example, come in all manner of shapes, sizes and colours without any noticeable gradations in between.