Three explanations for a “just right” universe?
An amazing discovery of scientists, in recent decades, is that many properties of the universe are “just right” for life. To understand why scientists think the universe is fine tuned to allow life, imagine that you are sitting in front of a control panel with dozens of dials. To allow life, each dial — which controls one property of the universe — must be tuned to a specific setting within a very narrow range. You are alive, reading this web-page, because all dials are properly tuned, and this produces a wide variety of life-permitting natural phenomena that include stable atoms and molecules, stars that produce the energy and atoms needed for life, the amazing chemistry of DNA, water, and proteins, and much more. Most scientists are convinced that constraints on a life-allowing universe are very tight, that small changes would make the existence of intelligent life impossible. Based on scientific evidence, there is little doubt about this conclusion. But there are two main theories (
