The Fine-Tuning Problem

The universe's physical constants appear remarkably fine-tuned for life. Strengthen or weaken the strong nuclear force even slightly and stars could not form as they do. Nudge the cosmological constant and the universe either collapses at once or expands too fast for galaxies to form.

A multiverse with random constants in every bubble offers a tidy answer to this puzzle. But it comes at a price that ties back to the falsifiability worry: if every possible universe exists, the theory can explain any fine-tuned value yet predicts nothing specific we could go out and measure.