Most serious versions of inflation — the same physics we use to explain why the universe is so flat and uniform — naturally predict that our Big Bang was just one of many. This series walks the argument, then lets you poke the ideas.
Eternal inflation keeps spawning new bubble universes — potentially with different physical laws. We can’t see the others. They’re past our cosmic horizon.
Not sci‑fi fan service — a consequence many cosmologists take seriously because inflation already works so well for our observable patch.