Is the multiverse science or religion?

Image source: Wikimedia Commons.

Some scientific controversies arise in disputes over the results. The stream cast off the James Webb Space Telescope data, for one. Others sound like clashes over philosophy – claims about the multiverse (countless universes out there) are a good example.

Theoretician physician Sabine Hossenfelder tackles the multiverse in his new book, Existential Physics: A Scientist’s Guide to Life’s Biggest Questions (2022). She also tackles the subject concisely – and with wit – in a short video and blog post on Return(Re)Action. It examines three popular multiverse models: Many Worlds, Eternal Inflation, and String Theory Landscape.

“Maybe we’ll never know”

Here is his point of view Eternal inflation:

We don’t know how our universe began and we may never know. We just talked about it the other week. But according to a currently popular idea called “inflation”, our universe was created from a quantum fluctuation of a field called “the inflaton”. This field supposedly fills an infinitely large space and our universe was created from a tiny bit of it, the bit where the fluctuation occurred.

But the field continues to fluctuate, so there are endless other universes fluctuating in existence. This creation of universes goes on indefinitely, which is why it is called eternal inflation. Eternal inflation, by the way, lasts forever in the future, but still requires a start in the past, so it doesn’t remove the Big Bang problem.

In Eternal Inflation, other universes may contain the same matter as ours, but in slightly different arrangements, so there may be copies of you in them. In some versions, you became a professional ballet dancer. In some cases, you have won a Nobel Prize. In yet another, you’re a professional ballet dancer who won a Nobel Prize and dated Elon Musk. And they are all as real as this one.

Where is this field of inflation that would have created our universe? Well, physicists say it collapsed into the particles that we observe now, so it disappeared and that’s why we can’t measure it. Yeah, that’s a bit sketchy.


Don’t miss his take on Many Worlds and the String Theory landscape, especially if you want to experience “elephants in the room that you can’t coincidentally see” – oh, and get married to Elon Musk (but maybe to be only in this universe). More seriously, she later addresses the specific claims of physicists who champion the idea.

The concept of multiverse derives from an alternative interpretation of the movement of elementary particles in quantum mechanics – alternative, that is, to the most widely accepted Interpretation of Copenhagen. In the Copenhagen interpretation, if the particle goes left rather than right, the universe simply updates. In the alternative Interpretation of many worlds, a new universe is created in which the particle goes straight. There are other versions but this is the best known.

Read more on The mind matterspublished by the Bradley Center for Natural and Artificial Intelligence at the Discovery Institute.