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Choose your world?…

SkyHarbor, 2009/12/08 

many worlds

hmm… sounds vaguely familiar…

Many worlds… Many many worlds… Many many MANY worlds! Could we really live in a ‘multiverse’ where there are an effective infinity of ‘universes’, with gazillions more popping up all the time? Is it even possible? To decide, a brief review of the “Many-Worlds” hypothesis is probably in order…

Formulated by Hugh Everett III as part of his physics doctoral dissertation at Princeton under thesis advisor John Wheeler, a slightly modified version was first published in 1957 as “The Theory of the Universal Wave Function” (nice title!). The article was greeted with deafening silence from the physics community, but it has since become regarded as one of the more intriguing interpretations of quantum uncertainty…

The “Many-Worlds Interpretation” as it came to be called, was an attempt to resolve a perceived paradox in the uncertainties involved in quantum theory. To illustrate the issue, Irwin Schrödinger’s famous thought (gedanken) experiment about the quantum superposition of states is useful. I will rashly assume at least a nodding acquaintance with “Schrödinger’s Cat” (a refresher is available here: Schrödinger’s Kitty ).

hugh everett
Hugh Everett III

“Many-Worlds” simply says that in the case of Schrödinger’s Cat, there is no paradox at all. Instead, the universe has ‘budded off’ into two alternative universes… one with a living kitty, and one with a dead one! One universe where we’re buying more meow-mix, and one where we’re digging a hole in the back yard…

Now, extend this to every single yes/no, left/right, nuclear decay/non-decay event that happens everywhere and everywhen! Jeez, it sure seems that things would get pretty damn crowded in rapid order! Could this possibly be true?

As intriguing an idea as it is, I doubt it. My view is that Everett’s “Many-Worlds” was symptomatic of a general discomfort with the ‘uncertainty’ that is integral to quantum physics. Remember that even the great Albert Einstein, whose 1905 paper on the ‘photoelectric effect’ helped give birth to quantum theory (and which won him the 1921 Nobel prize for Physics), could never come to grips with uncertainty. As he famously said, “God does not play dice!”¹.

Well, as it turns out, ‘god’ does indeed ‘play dice’, and even engages in “spooky action at a distance” as Einstein disparagingly referred to the now observed and verified phenomenon of ‘particle entanglement’.

There are several alternatives to “Many-Worlds” and the ubiquitous “Copenhagen” interpretations of quantum weirdness. Two worthy of mention include Louis de Broglie and David Bohm’s Pilot Wave² and John Cramer’s related Transactional Interpretation³…

I suppose my chief objection to “Many-Worlds” is that although it is a brilliant and self-consistent solution, it is deeply unsatisfying in an aesthetic sense. The idea that there are ‘universes’ where I exist (like this one) and others where I don’t doesn’t bother me… it’s just that such a ‘multiverse’ (infiniverse?) is way too ‘messy’ for my taste. Call me a minimalist, but I much prefer a frothy energetic vacuum where uncertainty is just the way things are! But then of course, the Universe doesn’t really care what I think, does it?

There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.

and mine too!

- Sky



¹ to which Stephen Hawking much later replied: “Not only does God play dice, He sometimes throws them where they cannot be seen!”

² this is refuted by Bell’s Theorem, which disallows ‘hidden variables’. David Bohm however, remains a hero of mine for his principled defence of J.R. Oppenheimer…

³ I briefly met Prof. Cramer after a lecture he gave at UW… a smart man!


5 Comments »

  1. Frank Discussion wrote,

    Personally, I lean towards Information Theory as an interpretation of a lot of the quantum weirdness (‘It from Bit’ as Wheeler put it). For instance, it neatly explains why you can’t know the position of a particle AND the velocity at the same time: if there is only one bit of information it can only give the answer to ONE question at a time. The theory, based on the idea that information is physical, has also gone far to aid in the creation of quantum computers as well as quantum teleportation (see http://www.quantum.at/fileadmin/quantum/documents/New_Scientist__In_the_beginning_was_the_bit.pdf )

    Comment on 2009/12/08 @ 10:14 am

  2. Cat-eyes wrote,

    Read the Nature article when it came out. Always interesting.

    Comment on 2009/12/08 @ 11:34 am

  3. byronius wrote,

    I’ll read this at lunch.

    Comment on 2009/12/08 @ 12:11 pm

  4. SkyHarbor wrote,

    I didn’t see the Nature article, but thought the cover was retro-cool!

    Comment on 2009/12/08 @ 12:19 pm

  5. byronius wrote,

    PS: Hugh Everett is much more famous as the father of Charles Everett, otherwise known as E of the Eels, the greatest songwriter who has ever lived.

    Lennon and McCartney a close second.

    Roger Waters in there somewhere.

    Comment on 2009/12/09 @ 1:57 pm

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