Letters from an Astrophysicist

by Neil deGrasse Tyson

Dear Kevin, Zero chance that Earth is five or six thousand years old. As I say often, if you use religious texts to predict future knowledge of the physical universe, you will get the wrong answer. But it’s not for want of trying. More accurately stated: every previous attempt at this exercise has failed. Consider instead Galileo’s dictum§: “In my mind God wrote two books. The first book is the Bible, where humans can find the answers to their questions on values and morals. The second book of God is the book of nature, which allows humans to use observation and experiment to answer our own questions about the universe.” Galileo was a religious man, but was nonetheless compelled to say: “I do not feel obliged to believe that the same God who has endowed us with senses, reason and intellect has intended us to forego their use and by some other means to give us knowledge which we can attain by them. He would not require us to deny sense and reason in physical matters which are set before our eyes and minds by direct experience or necessary demonstrations.” Just to be clear, the existence or non-existence of God has nothing to do with the age of the Earth. Most (> 80%, is my guess) of western religious people recognize this. Those who link Earth’s age with whether or not God exists are a small minority of the religious community. They just happen to be louder than most others, giving the (false) impression that they are mainstream and represent the majority. There are extensi...