Parallel Universes

Hugh Everett was too wrapped up in his thoughts to be a parent

The Many Worlds of Everett

In April 1959, Hugh Everett III,along with his wife and baby daughter, went to Copenhagen, Denmark, to meet Niels Bohr and his colleagues. He was very excited. He had just completed his PhD thesis, called "Many Worlds Interpratation of Quantum Mechanics" and he was thinking that this was going to change the perspective of the whole quantum physicists. A bit eccentric and self-centered, he even thought he could be the Einstein of his era, to whom he was sending letters at the age of 12.

Niels Bohr talking to Hugh Everett ( 2nd one on the right),at the age 24

Contrary to his expectations, his trip to Copenhagen turned out to be a complete disaster. He was literally mocked by his fellow physicists, to the point that Léon Rosenfeld, one of Bohr's followers, described Everett as being "undescribably stupid and could not understand the simplest things in quantum mechanics". 

But what was Everett claiming that made Bohr and his colleagues so irritated? Let's give some insight first.In the quantum world, an elementary particle, or collection of those particles, can exist in a superposition of two or more possible states at the same time. For instance, an electron can be in a superposition of different locations, velocities and orientations of its spin. Yet anytime scientists try to measure one of these properties, they see a definite result. (just one of the elements of the superposition, not a combination of them).

Many of the founders of the quantum mechanics, namely Bohr, Heisenberg, von Neumann, had agreed on an interpratation of quantum mechanics - Copenhagen Interpratation , to deal with the "observer" problem. According to this view, at the moment of measurement, the wave function describing the superposition of alternatives appears to collapse into one member of the superposition, thereby interrupting the smooth evolution of the wave function and introducing discontinuity. However, there was one man who wasn't buying this: Hugh Everett.

Instead of Schrödinger's wave function, which can be thought of as a list of all the possible configurations of a superposed quantum system, he introduced  a universal wave function,that links observers and objects as parts of a single quantum system.Everett’s radical new idea was to ask, "What if the continuous evolution of a wave function is not interrupted by acts of measurement?". According to him, the universal wave function would contain every probability making up the object's superposition. He thought, all of these alternatives were part of the reality, which are branched and do not influence one another once formed. ( according to a fundamental property of Schrodinger's equation). For instance, during the measurement, although we are observing a definite result, in fact, all the possibilites that could happen, were happening in a different branch. He called these branches "many worlds".

Hugh Everett and his daughter Liz

Everett's family did not end up well. He left physics after completing his PhD, due to the lack of interest to his work and instead worked in defence industry. His daughter Lisa, who were having mental problems, commited suicide in 1996, leaving a note that "she was joining her father in a parallel universe." His wife died of cancer later, and the only surviving member of the Everett's family, Mark Oliver Everett turned out to be a rockstar, the lead singer of the alternative rock band Eels, who prepared a document describing his father and their relationship, called "Parallel Worlds, Parallel Lives".

Everett's great idea , although met scorn at his time, revealed that there are different universes where all of the physically possible events were actually happening. This was also a great cure for paradoxes related with the Double Slit Experiment and Schrödinger's Cat. "Many-Worlds" of Everett are later described by Max Tegmark, who is now a  top-physicist in MIT, as Level-III parallel universes. Apparently, he has 3 more.

The Universes of Tegmark

Max Tegmark is an iconoclast physicist in the Physics Department of MIT and he is the leading supporter of the "multiverse" idea in the physics world today. But why did this whole multiple universes idea suddenly start to sound reasonable to most of the physicists around the world? Well, because the M-theory suggested that our universe was made up of 11 dimensions, and the theory of inflation suggested that our universe was actually infinite.

So according to Tegmark, Level-I universes directly result from the fact that the universe is infinite. If space goes on forever, then there must be other regions like we live in—in fact, an infinite number of them. No matter how unlikely it is to have another planet just like Earth, we know that in an infinite universe it has to happen.

Level-II universes emerge if the fundamental equations of physics, the ones that govern the behavior of the universe after the Big Bang, have in fact more than one solution. So actually at the very moment of Big Bang, other universes with different kinds of physical laws, different solutions to those equations, might have emerged spontaneously . Universes with different realities that we cannot perceive!

Max Tegmark while explaining the birth of the universe

Level-IV universes is a phenomena invented by Max Tegmark himself. Max Tegmark has this crazy idea, called "Mathematical universe hypothesis", that the reality itself is not only described by math, but it is math! Therefore every statement in abstract mathematics in fact describes different realities and physical existences. So these other mathematical universes are made up of "external" realities, which are independent from our owns.

The moral implications of Parallel Universes

So, these all seem very abstract, but what are the implications of this idea? Well, the first implication, that is every physically possible event is actually happening elsewhere could be a comforting or dangerous idea at the same time. It may be comforting because you know that you are living an "ideal life"in another universe, in which you might be a rockstar, the top scorer in Premier League, the Nobel prize-winner, or in which you are never born.

Travis is rocking not only one, but multiple universes- You just can't see them.

It is also a dangerous idea because for instance if you commit armed robbery and shoot the cashier, why should it be a crime, while there are other universes in which it is actually not considered as a crime? Or as an alternative thought, after all, there are millions of parallel universes in which you didn't do it, or in which he shot you! That destroys the whole "universal" morality concept and leaves us with an infinite amount of choice for moral values and standards!

Now, you might think reading this article was totally a waste of time. But I assure you this will be a big hit in another universe.

If you are interested to read more about this subject, see:

"The Many Worlds Interpratation of Quantum Mechanics" Hugh Everett

"The Many Worlds of Hugh Everett", Scientific American

"Parallel Universes", Max Tegmark

"The Mathematical Universe", Max Tegmark

"Parallel Worlds, Parallel Lives", BBC Horizon Documentary

"Parallel Universes", History Channel