Leonardo da Vinci thought of the earth as a vast organism, whose features and functions were in many ways analogous to the human body. Well if the Earth has a lifetime, like you and I, is it an infant? An adolescent? A senior?
I’m Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.
“So we know that the Earth’s lifetime can’t be any longer than the lifetime of a star. We know something about the probable lifetime of the sun, which is on the order of ten billion years. We know the age of the Earth, which is about five billion years. So the Earth is about halfway through its potential lifetime — it’s middle-aged.”
Charles Langmuir is a Professor of Earth and Environmental Science at Columbia University.
“Now if we want to carry the analogy somewhat further, we can do it in a similar way to the way we think about our pets. We talk about one dog year being equivalent to seven years of our life, because a dog’s life is only about ten years long. So in the same way as we can think about what it might feel like to be a dog, we can also think what it might feel like to be an Earth, for all the various processes that are happening to it. So the Earth is now middle-aged; life and the geological record would have begun for the Earth at about age seven. More strikingly in this Earth’s lifetime, it would be as if the earliest humans appeared on Monday, that civilization and the written word began about an hour ago, and the scientific revolution occurred at the beginning of this sentence. So in terms of the impact of Man, and how the Earth has been changing, we can see that Man is both almost instantaneous and incredibly revolutionary, in terms of its influence on the planet.”
Additional funding for Pulse of the Planet has been provided by the National Science Foundation. I’m Jim Metzner.