Cutting an apple
Greek philosopher Democritus of Abdera (around 460 – 370 BC) believed in the existence of atoms. Legend says that Democritus once sat by the sea, held an apple in his hand, and thought: “If I cut this apple into two parts, I get half an apple; if I cut this half again into two parts, I get a quarter of an apple. If I continue dividing this way, I get an eighth, a sixteenth of the apple, etc. How many times must I divide the apple in this way until I reach its smallest, further indivisible part – the atom?”
Here is the answer:
Let’s assume that Democritus’ apple had a volume of about 1dm3, which is 10–3m3. Its volume after n-fold division is
which is at the same time the volume of a single atom. Austrian physicist J. Loschmidt (1824 – 1895) found that the diameter of an atom is about 10–10m, so the volume of an atom is
Already after the 90th division of the apple, Democritus would have reached his goal.