The universe we see –stars, moons, planets, galaxies– is but a small, accidental tip of an infinite cosmic iceberg. During the epoch of inflation, thought to have been triggered by the phase transition that marked the end of the grand unification at approximately 10−36 seconds after the Big Bang, the accelerating expansion of space was far more dramatic than in today’s universe, expanding at an absolutely staggering rate, tearing space asunder. During this period no objects—even two elementary particles—remained close enough to one another for long enough to interact.
“Dark energy is incredibly strange, but actually it makes sense to me that it went unnoticed,” said Noble Prize winning physicist Adam Riess in an interview. “I have absolutely no clue what dark energy is. Dark energy appears strong enough to push the entire universe – yet its source is unknown, its location is unknown and its physics are highly speculative.”
It’s possible that the universe isn’t uniform past what we can see, and conditions are wildly different from place to place, says Caltech astrophysicist Sean Carroll. “That possibility is the cosmological multiverse. We don’t know if there is a multiverse in this sense, but since we can’t actually see one way or another, it’s wise to keep an open mind.”
“By the end of this century, be able to ask whether or not we live in a multiverse, and how much variety its constituent “universes” display. The answer to this question will determine how we should interpret the “biofriendly” universe in which we live (sharing it with any aliens with whom we might one day make contact).”
“I think I know how the universe was born,” said Andrei Linde, Russian-American theoretical physicist and the Harald Trap Friis Professor of Physics at Stanford University. Linde is one of the main authors of the inflationary universe theory, as well as the theory of eternal inflation and inflationary multiverse.