“[T]he universe that we know is immensely large and complex. Its extension in time and space is beyond human scale and comprehension. The universe is 15 billion years old; our sun is 4.5 billion years old. In contrast, our human species appeared only 130,000 years ago and the first cave paintings only 35,000–50,000 years ago. The numbers alone enforce both a sense of perspective and humility. Humbling, too, is the knowledge that we are intimately connected with the universe ‘all the way up and all the way down,’ because we know that chemically and biologically we share a common ancestry with both the stars and the simplest life forms.”

—Dennis Ford, The Search for Meaning: A Short History, 2007.