Zero

1) ''To Pythagoras, playing music was a mathematical act. Like squares and triangles, lines were number-shapes, so dividing a string into two parts was the same as taking a ratio of two numbers. The harmony of the monochord was the harmony of mathematics -- and the harmony of the universe. Pythagoras concluded that ratios govern not only music but also other types of beauty. To the Pythagoreans, ratios and proportions controlled musical beauty, physical beauty, and mathematical beauty. Understanding nature was as simple as understanding the mathematics of proportions.''

2) ''How big are the rational numbers? They take up no space at all. It's a tough concept to swallow, but it's true.
Even though there are rational numbers everywhere on the number line, they take up no space at all. If we were to throw a dart at the number line, it would never hit a rational number. Never. And though the rationals are tiny, the irrationals aren't, since we can't make a seating chart and cover them one by one; there will always be uncovered irrationals left over. Kronecker hated the irrationals, but they take up all the space in the number line.''

3) ''Zero might also hold the secret of what created the cosmos. Just as the nothingness of the vacuum and the zero-point energy spawn particles, they might spawn universes. The froth of quantum foam, the spontaneous birth and death of particles, might explain the origin of the cosmos. Perhaps the universe is just a quantum fluctuation on a grand scale -- an enormous singular particle that came into existence out of the ultimate vacuum. This cosmic egg would explode, inflate, and create the space-time of our universe. It may be that our universe is simply one of many fluctuations. Some physicists believe that the singularities at the center of black holes are windows into the primordial quantum foam before the big bang -- and the froth of foam at the center of a black hole, where time and space have no meaning, is constantly creating countless numbers of new universes that bubble off, inflate, and create their own stars and galaxies. Zero might hold the secret to existence - and the existence of an infinite number of other universes.''