Artistic impression of a Multiverse — where our Universe is only one of many. According to the research, varying amounts of dark energy have little effect on star formation. This raises the prospect of life in other universes — if the Multiverse exists. (JAIME SALCIDO/SIMULATIONS BY THE EAGLE COLLABORATION)

What Is (And Isn’t) Scientific About The Multiverse

Our best physical theories predict that a multiverse exists. But if we can’t test it, is it really scientific?

The Universe is all there ever was, all there is, and all there will ever be. At least, that’s what we’re told, and that’s what’s implied by the word “Universe” itself. But whatever the true nature of the Universe actually is, our ability to gather information about it is fundamentally limited.

It’s only been 13.8 billion years since the Big Bang, and the top speed at which any information can travel — the speed of light — is finite. Even though the entire Universe itself may truly be infinite, the observable Universe is limited. According to the leading ideas of theoretical physics, however, our Universe may be just one minuscule region of a much larger multiverse, within which many Universes, perhaps even an infinite number, are contained. Some of this is actual science, but some is nothing more than speculative, wishful thinking. Here’s how to tell which is which. But first, a little background.

There is a large suite of scientific evidence that supports the picture of the expanding Universe and the Big Bang. The entire mass-energy of the Universe was released in an event lasting less than 10^-30 seconds in duration; the most energetic thing ever to occur in our Universe’s history. (NASA / GSFC)