How Special Is Our Universe?

If the fundamental constants of nature differed from their measured values, life as we know it would not have emerged. Stars are witness to the forces of electromagnetism and gravity - displace this equilibrium and the existence of nuclear-burning stars is at risk. In such a universe, stars would never have formed, or might have collapsed to black holes.

Theories of the multiverse suggest that life-containing universes are incredibly rare. We live in one of these, whether by cosmological natural selection or by the consequences of a theory yet to be formulated.