COULD PARALLEL WORLDS BE REAL?

Virtual representation of Parallel Universes

(Photo: Cosmos Magazine)

Have you ever asked yourself if you could be living within a Parallel Universe? Then, do not hesitate to read the article below of the Cosmos Magazine to know more about them:

“David Wallace was still in high school when he first encountered the notion of parallel universes. To a British teenager hooked on science fiction and physics, it sounded “weird but cool”, he recalls. Twenty years later, the topic still absorbs him.

A professor specialising in the philosophy of physics at the University of Southern California, he recently penned a book titled The Emergent Multiverse.

For some people, the idea there is more than one universe out there sounds absurd. Sure, it’s fair game for the writers of Star Trek, and perhaps even for philosophers, but how can it be a serious scientific idea?

In fact, it was first put forward some 60 years by a very serious physicist, Hugh Everett III, who proposed the idea of “Many Worlds” as a way of making sense of quantum mechanics – the strange science of the subatomic world.

Everett’s idea was not well received. But by the time Wallace was wrestling with quantum mechanics as a physics PhD student four decades later, the idea had been resurrected. “What was a revelation to me was realising that these parallel ‘worlds’ weren’t something extra that you added to quantum mechanics; they were there in the mathematics of the theory all along. And it was realising that that got me thinking, ‘Ok, this is probably right – or at least, this is the best route that we have at the moment to try to make sense of this’.”

Quantum mechanics isn’t the only theory that leads scientists to the idea of parallel universes. String theory – an attempt to stitch gravity into the equations that govern the quantum world by proposing the existence of 11-dimensional vibrating strings – also suggests our universe is just one of many in a vast cosmic landscape. Meanwhile, inflation theory holds that our universe inflated as a bubble of space-time shortly after the Big Bang. If it happened once, then perhaps it happened many times and is still happening.

Of these various paths to parallel worlds, the one that emerged from quantum mechanics, now referred to as “Many Worlds”, was the first out of the gate. It’s rooted in mathematics, and it wouldn’t be the first time that this esoteric language unveiled a hidden reality. The Big Bang, black holes and the concept of curved space, for instance, all first emerged from a scrawl of mathematical equations. Now evidence they exist is virtually bulletproof. We can hear the “echo” of the Big Bang the cosmic microwave background radiation – with radio telescopes. Just last year, we detected the gravitational signatures of colliding black holes. And Uber drivers would be lost if Google Maps didn’t take account of Einstein’s curved space-time.

So can we find any evidence for the existence of Many Worlds? Probably not. But advocates say that’s not a deal breaker. They consider Many Worlds to be just one more of the predictions of quantum mechanics – a theory whose other predictions have been exhaustively proved. Because of that, a surprising number of respectable physicists are willing to entertain the reality of multiple worlds.

Clues to the weirdness of our universe began to emerge in the early 1900s when the founders of quantum physics, including Max Planck, Albert Einstein and Werner Heisenberg in Germany, along with Niels Bohr in Denmark, began to investigate the structure of the atom.

It was Planck who showed that energy came in discrete bundles or quanta. Einstein backed him up by showing that light radiates its energy as bundles that we now call photons. Yet for 100 years before that, light was understood to be a wave. Now scientists were forced to think of light as both a particle and a wave.

Then in the 1920s, a young Frenchman named Louis de Broglie argued this type of behaviour wasn’t restricted to light: any kind of particle should display this duality. He described the idea of “matter waves” in his doctoral thesis in 1923. The counterintuitive notion almost cost him his degree, until Einstein gave it a nod of approval.

Bizarre as the idea was, Austrian physicist Erwin Schrödinger nevertheless found he could describe matter waves with a mathematical equation called the “wave function”.

Schrödinger’s equation did not describe a world that we experience. Tracking a subatomic particle was nothing like describing the position and velocity of a fired cannonball. Rather, his wave function described particles as some sort of statistical entities. All one could do was describe the likelihood of where and when to find them. Schrödinger attempted a grasp on reality by imagining matter waves as being something like “smeared-out” particles.

Of all the tests of quantum mechanics conducted over the years, the one that sheds the most light on this weird science is the decidedly low-tech double slit experiment.

 (Cosmos Magazine, 2017)

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