Confirming inflation would mean that the universe we see, extending 14 billion light-years in space with its hundreds of billions of galaxies, is only an infinitesimal patch in a larger cosmos whose extent, architecture and fate are unknowable. Moreover, beyond our own universe there might be an endless number of other universes bubbling into frothy eternity, like a pot of pasta water boiling over.
Carl Sagan talks about the possibility of an electron being a whole universe in the Cosmos episode The Edge of Forefever (around 55 minutes and 10 seconds in):
If the Cosmos is closed, there’s a strange, haunting, evocative possibility — one of the most exquisite conjectures in science or religion. It’s entirely undemonstrated — it may never be proven — but it’s stirring. Our entire universe, to the furthest galaxy, we are told, is no more than a closed electron in a far grander universe we can never see. And that universe is only an elementary particle in a still greater universe, and so on, forever. Also, every electron in our universe, it is claimed, is an entire miniature cosmos, containing galaxies and stars and life, and electrons. Every one of those electrons contains a still smaller universe — an infinite regression, up, and down. Every human generation has asked about the origin and fate of the cosmos. Ours is the first generation with a real chance of finding some of the answers. One way or another, we are poised at the edge of forever.
Einstein knew that general relativity did not mesh with another theory of physics called quantum mechanics. Whereas general relativity talks about gravity and the universe as a whole, quantum mechanics talks about the small scale of particles and the other forces of nature, the strong and weak nuclear forces, and electromagnetism. Despite almost a century of effort, the world’s physicists have not been able to show how these theories work together. The primordial gravitational waves were generated when gravity and the universe were working on the same scale as particles and the other forces of nature. This detection and the subsequent analysis will hopefully tell us how. If it does, this could lead to what physics wistfully call “the theory of everything”.