Life, Design and the Multiverse

Fine-tuning evidence has raised compelling questions about the universe's beginning, evolution and eventual end.

Every science student can recall having to memorize certain important numbers during their school years: the gravitational constant, the speed of light and Avogadro’s number, to name a few. In recent years, scientists have found extremely precise values for these fundamental constants. But what if the value of these constants were ever so slightly different? In some cases, life would not even exist.

In recent years, physicists have increasingly accepted the idea that our existence implies that certain properties of the universe could not have been different. In other words, some of these properties — particularly the fundamental constants — might be “finely-tuned” to support life. This “anthropic” reasoning has been around since the early 1970s but gained wider support in the 1980s when Steven Weinberg, a Nobel laureate in physics, used the idea successfully in the realm of cosmology.