“Many and strange are the universes that drift like bubbles in the foam upon the River of Time.”
—Arthur C. Clarke, The Wall of Darkness
What is the Multiverse?
That’s one question I’m often asked from readers of my book, Mauna Kea Rising. It’s a great question. It’s hard enough to understand the vastness of our own universe without grappling with the mind-boggling concept of parallel worlds in alternate universes!
But what if our universe is not the only one, but part of an infinite set of universes in a cosmic landscape? That’s one conclusion that many cosmologists and quantum physicists are now pondering. For reasons that I will explore in this series of articles, the Many-Worlds Interpretation answers stubborn questions raised by quantum mechanics since its ascension in the 1930s. From the enigmatic Schrödinger’s Cat paradox to the famous double-slit experiment, quantum physics has confounded us. As Feynman advised, “If you want to understand quantum mechanics, just do the math …the ‘paradox’ is only a conflict between reality and your feeling of what reality ‘ought to be.’”
Yet, this leaves me a little empty inside, wanting a more intuitive answer. Perhaps we’d have a better understanding of these paradoxes by envisioning multiple universes laying side-by-side like sheets of paper, hidden within other dimensions outside of our everyday experience. If M-theory proves sound, we’ll face the uncomfortable notion that even the familiar dimensionality of three-dimensional space and time must be expanded to eleven dimensions. However weird this may seem; this idea is not new.
In 1584, Giordano Bruno shocked the Church by proposing that “the excellence of God might be magnified, and the greatness of his kingdom made manifest [if] he is glorified not in one, but in countless suns; not in a single earth, but in a thousand, I say, in an infinity of worlds.”
We’ve come a long way from this candle in the darkness. Today, the idea of the multiverse seems all around us in popular culture. Olaf Stapledon was the first to envision parallel worlds in fiction with his book, The Star Maker. Arthur C. Clarke considered it one of the finest works of science fiction ever written. In this profound novel, Olaf imagined an infinite number of universes, each a branch from a previous one, “exfoliated from every moment of every temporal sequence in this cosmos.” Quantum mechanics predicts that a particle has multiple “states”, such as simultaneously passing through door number one or door number two. The particle travels in both “worlds” in superposition. It’s only after we observe this particle, that it “chooses” which door to take. It’s as if our observations decide the fate of the particle. Now let’s extrapolate this paradigm out to the macroscale. Does this mean we have no free will? Do our actions result only from observations by another being—after the fact?
The Many-Worlds Interpretation would say no. The American physicist Hugh Everett first proposed this new interpretation of quantum physics where every possibility embodied in Schrödinger’s probability waves is realized in one of a vast landscape of an infinite number of universes. The quantum multiverse creates a new universe when a diversion in events occurs, known as a “branch-point”. When we decide on which door to take (of our free will), we create a branch-point in our timeline. In this way, a new universe branches from the previous one, creating a new world timeline. One copy of us goes through the first door, and another copy of us passes through the second.
Literature, television, and film continue to explore quixotic themes of parallel worlds or alternative histories. My favorite version of a parallel universe is The Wizard of Oz. Was it all just a dream, Dorothy? And let’s not forget more modern variations of this theme in the Star Trek episode The City on the Edge of Forever, the Borges story The Garden of Forking Paths, and the J.J. Abrams’ Fringe. Philip K. Dick’s novel The Man in the High Castle envisions a parallel world in which Japan and Germany won the Second World War. Collectively, these and many other works of popular culture have moved the concept of parallel realities into our zeitgeist and fueled public fascination with multiverse.
The parallel worlds envisioned in my science fiction series, Lost in the Multiverse, are part of what cosmologist Max Tegmark and string theorist Brian Greene call a “Level III” Multiverse. The parallel world setting for Mauna Kea Rising is one of many twin Earths born from branch-points created by time-travelers and their haphazard (or selfish) meddling with the world timeline.
What’s next:
In future articles, I’ll explore why we think parallel worlds exist. I’ll also summarize the search for their existence, or at least ways in which we might test the Many-Worlds Interpretation of quantum mechanics. And what if we could travel to these other worlds, then what might they look like?
For Further reading:
Brian Greene. The Hidden Reality. Knopf Doubleday Publishing Group, 2011.
John Gribbin. In Search of the Multiverse: Parallel Worlds, Hidden Dimensions, and the Ultimate Quest for the Frontiers of Reality. Turner Publishing Company. Kindle Edition.
Jorge Luis Borges, Collected Fictions, trans. Andrew Hurley, Allen Lane, 1998.
Michio Kaku. Parallel Worlds: A Journey Through Creation, Higher Dimensions, and the Future of the Cosmos. Knopf Doubleday Publishing Group, 2006.
M.W. Kelly. Mauna Kea Rising. Hokulei Press, 2019
Olaf Stapledon. Star Maker. Millennium Paperbacks, 1937.