Sometimes the world seems suspiciously perfect. There seems to be no rhyme or reason for why gravity is 10 36 times weaker than electromagnetism. Or why a neutron is 1.00137841870 times heavier than a proton. But these seemingly random, yet precise, values landed in the extremely narrow window that would allow life to exist.
How did we end up in such a precariously balanced universe? How did we get so lucky?
Some physicists think there could be many—maybe infinite—universes. Other universes could be empty—or they could be full of things we never imagined. Perhaps we just live in the only one that can support us.
Picks for further reading
Harper’s Magazine: The Accidental Universe: Science’s Crisis of Faith Alan Lightman delves into the history of the fine-tuning problem—and makes a case for the multiverse.
The Nature of Reality: Is the Universe Fine-Tuned for Life? Anil Ananthaswamy examines the scientific community’s support for and resistance against the possibility of a multiverse.