One of the most disturbing science-fiction novels I have ever read is Jack Womak’s 1993 opus Elvissey, which takes place in a dystopian future in which a rising religion is centered upon the worship of the late Elvis Presley, whom the devout believe was a demigod with miraculous powers. A giant multinational corporation, Dryco, decides to co-opt the movement by staging a second coming, which of course would require a duplicate Elvis.
Fortunately, the technology to travel in time and visit alternative universes exists. To that end, two Dryco operatives travel to an earlier point in time in a parallel reality, on a mission to kidnap a younger version of Elvis and bring him back. Sounds easy, but things get complicated. The world into which they emerge is a decidedly bad neighborhood. World War II had a different outcome, and Nazi flying saucers now buzz the skies of America. Instead of integrating, the South opted for ethnic cleansing and genocide. And instead of being a rock-and-roll sensation, the alternate Elvis is a violent, mentally-ill criminal with a belief in a brand of early Christian Gnosticism, which holds that reality was created by an evil intermediary to God. I don’t want to spoil the ending for you, but it gets worse from there.
Parallel universes are a staple of science fiction, from Lester Del Rey’s 1966 novel The Infinite Worlds of Maybe to TV shows such the 1990s’ Sliders and the current Fox show Fringe, in which an alternative reality version of the U.S. map has a different number of states, and half of California is mysteriously missing. But the concept actually is thousands of years old. As Stefan Einhorn notes in A Concealed God: Religion, Science and the Search for Truth, Indian Hinduism assumes that the reality we experience is just one of many, and that these parallel worlds are unaware of one another’s existence.
Nevertheless, the notion of a multiverse, in which there are a plethora of realities corresponding to every conceivable variation in the state of things, is a bit tough for some of us to get our heads around. That’s why theoretical physicist Steven Hawking shocked many when he matter-of-factly explained in his 2010 book The Grand Design that parallel realities to ours must exist, as a requisite for the quantum physics model of reality to work.
While some of these universes are similar to ours, most are very different. They aren’t just different in details, such as whether Elvis really did die young or whether turnips are a dessert food, but rather they differ even in their fundamental laws of nature. In fact, many universes exist with many different sets of physical laws.
While Hawking’s statement generated news headlines and puzzlement among laymen, none of what he said was particularly novel. The many-worlds-interpretation (MWI) postulate was first articulated by Hugh Everett back in 1957, as a way of reconciling some of the troubling paradoxes of quantum mechanics. The Stanford Encyclopedia of Philosophy, that veritable Swiss army knife for autodidacts, offers this explanation in lay terms:
Every time a quantum experiment with different outcomes with non-zero probability is performed, all outcomes are obtained, each in a different world, even if we are aware only of the world with the outcome we have seen. In fact, quantum experiments take place everywhere and very often, not just in physics laboratories: even the irregular blinking of an old fluorescent bulb is a quantum experiment.
This idea can play out in some mind-bending ways. As University of Pennsylvania physicist Max Tegmark explains in this fascinating treatise,
Is there another copy of you reading this article, deciding to put it aside without finishing this sentence while you are reading on? A person living on a planet called Earth, with misty mountains, fertile fields and sprawling cities, in a solar system with eight other planets. The life of this person has been identical to yours in every respect–that is, until now, that is, when your decision to read on signals that your two lives are diverging.
Tegmark goes on to note that according to one cosmological model, your not-so-evil twin actually exists in a galaxy about 10 to the 10th power to the 29th power meters from where you sit.
How many parallel universes are there? According to this 2009 Physorg.com article, Stanford theoretical physicists Andre Linde and Vitali Vanchurin came up with an estimate of 10 to 10th power, to the 16th power. Oddly, that figure is based upon the maximum amount of data, about 10 to the 16th power bits, that a human mind is believed to be capable of amassing in a lifetime. Apparently, the number of possible realities is limited only by the ability to contemplate them. As it turns out, the spaced-out hippy guy that I chatted with in an incense shop in 1971 actually was onto something, when he pontificated that if you closed your eyes, chanted and imagined something really intensely, it existed somewhere.
Watch Naked Science: Living in a Parallel Universe, on Thursday May 19 at 8 p.m. And for a sneak preview into how the Big Bang Theory helps explain parallel universes, watch this: