Man in his ceaseless search after truth has discovered and partially explored five world. These worlds differ from each other in the size of the units of space and time we need to describe them. In our every day practical world, we get along nicely with such units as feet and seconds. In the chemical world of molecules and atoms, the electrons complete their revolutions in a hundred million millionth of a second, while a hundred million atoms side by side extend only a distance of one inch. Inside the nucleus of the atom, we enter a third world, where events happen a million times faster still, and distances are a thousand times smaller than in the atom. In the fourth world, the astronomers measure revolutions of the planets in years, and the unit of distance, the light year, is about ten thousand million miles. Finally, we come to the spiritual world where time is measured in eternities and space is limitless. Thus, in thought we can travel from the almost infinitesimally small to the infinitely large.
Source: Science and Your Faith in God
Contributed by: Zaady