On this scale, according to John McPhee in Basin and Range, the distance from the fingertips of one hand to the wrist of the other is Precambrian. All of complex life is in one hand, and in a single stroke with a medium-grained nail file you could eradicate human history.
In "A Short History of Nearly Everything," Bill Bryson highlights the vast expanse of geological time, using John McPhee's metaphor from "Basin and Range" to illustrate it. He describes a scale where the entire span of human history is so brief that it can be erased with a simple action, like a stroke of a nail file. This stark comparison emphasizes how recent human existence is in the grand scheme of Earth's long and complex history.
This perspective invites readers to consider the sheer scale of time that precedes us, with complex life occupying only a small portion of that timeline. It serves as a reminder of humanity's fleeting presence compared to the ancient processes that shaped the planet and life itself.
