The Many Worlds Interpretation of quantum physics has been around for nearly 60 years. It’s a highly controversial idea which suggests that our world — and everything in it — is constantly splitting into alternative timelines. If it’s correct, here’s what your true existence might actually be like.
Over a hundred years ago, the discovery of quantum physics ruined the party. Our comfortable, clockwork conception of universe was thrown into disarray with the realization that, at the micro-scale, there’s some crazy funky stuff going on.
Thanks to quantum mechanics, we now know that matter takes on the properties of both particles and waves. What’s more, thanks to Werner Heisenberg and Erwin Schrödinger, we can never be certain about a particle’s momentum and position, nor can we be certain about an object’s state when it’s not being observed. In other words, the universe — at least at a certain scale — appears to be completely fuzzy and nebulous. Possibly even random.
Quantum physics has royally messed up classical — and seemingly intuitive — principles of space and time, causality, and the conservation of energy. This means that Newtonian, and even Einsteinian, interpretations of the universe are insufficient. Indeed, if we’re to develop a unified and comprehensible theory of everything, we’re going to have to reconcile all of this somehow.
But some physicists, upset by the implications of quantum mechanics on our ultimate understanding of the universe and our place within it, still choose to ignore or dismiss it as a kind of messy inconvenience. And it’s hard to blame them. Quantum physics doesn’t just upset conventional physics. It also perturbs our sense of our place in the universe; it’s Copernican in scale — a paradigm changer the carries deep metaphysical and existential baggage.
Denial, however, won’t help the situation — nor will it further science. Physicists have no choice but to posit theories that try to explain the things they see in the lab, no matter how strange. And in the world of quantum mechanics, this has given rise to a number of different interpretations, including the Copenhagen Interpretation, the Ensemble Interpretation, the de Broglie-Bohm theory, and many, many others.
And of course, there’s the infamous Many Worlds Interpretation.
The “Relative State” Formulation
Back in the 1950s, a Princeton undergraduate by the name of Hugh Everett III embroiled himself in the wonderful and wacky world of quantum physics. He became familiar with the ideas of Niels Bohr, Heisenberg, and Schrödinger, and studied under Robert Dickie and Eugene Wigner. Then, in 1955, he began to write his Ph.D. thesis under the tutelage of John Archibald Wheeler.
In 1957, he published his paper under the name, “Quantum Mechanics by the Method of the Universal Wave Function.” Eventually, after further edits and trimming, it was re-published under the name, “Wave Mechanics Without Probability.” And though he referred to his theory as the “relative state formulation,” it was rebranded as the Many Worlds Interpretation (MWI) by Bryce Seligman in the 60s and 70s.
But like so many seminal theories in science, Everett’s idea was scorned. So scorned, in fact, that he gave up physics and went to work as a defense analyst and consultant.
Now, some 60 years later, his radical idea lives on among a small — but growing — subset of physicists. In a recent poll of quantum physicists, some 18% of respondents said they subscribe to the MWI (as compared to the 42% who buy into the dominant Copenhagen Interpretation).
The Everett Postulate
Essentially, Everett’s big idea was the suggestion that the entire universe is quantum mechanical in nature — and not just the spooky phenomenon found at the indeterministic microscopic scale. By bringing macroscale events into the picture, he upset the half-century’s worth of work that preceded him. The two different worlds, argued Everett, can and must be linked.
Read More: Here