Thursday, May 10, 2012

Quantum Immortality and Everett's Paradox

Yesterday, after a day of sociology and anthropology, I motored over to my in-laws on the SuperBee (what my little guy thinks I should call the Suzuki).

There, I chatted a bit with the mother-in-law about life and class.  Then, over a beer or two, I talked about waveform collapse and quantum mechanics with my physicist father in law.  It was a followon to a conversation with someone who kindly agreed to provide input to my writing, and it was...helpful.

Though temporarily sidetracked by writing and preparation for my D.Min. classes, the drafted manuscript for the Believer's Guide to the Multiverse continues to burble away happily on the back burner.   A few souls have read it so far, and feedback has been...well...the way feedback is when you put out that first draft of anything.

It's always a bit daunting, exposing the first tender shoots of a manuscript to outside inputs.   It's your baby, this tender delicate interweaving of ideas and hopes and concepts.  You've pored over it, loved it, struggled with it, and reached a point where you and your muse are almost content with it.

And then reality intrudes.  It's necessary.  It's a good thing.  A critical read over something is vital, and particularly a critical read from an expert eye.   For my little exploration of the implications of the Many Worlds interpretation of quantum mechanics, the expert eye needed was from someone with a Ph.D. in physics...and, being Presbyterian, finding such a soul in my congregation was achievable.  

The inputs were both significant and useful, and will strengthen the manuscript, once I've stopped quietly sobbing to myself.  One particularly helpful insight was that in plowing through the works of contemporary "popularized" physics that gave my layman's mind insight into the multiverse, I'd managed to truck right past the physicist who came up with the idea in the first place.  Not a mention.  Not a peep.   A good catch, that.

The physicist in question was Hugh Everett, whose 1957 dissertation provides much of the conceptual foundation for the Many Worlds hypothesis/interpretation in quantum theory.    Everett was an interesting fish on many fronts, and some more exploration of his thinking will be plugged into the manuscript once time allows.

Today I found myself ruminating on one of the more peculiar elements of Everett's personal thought: his belief in what was subsequently called "quantum immortality," which arises from an odd variant of the Shroedinger's Cat thought experiment, from the perspective of the cat.  The "quantum suicide" thought experiment involves a weapon pointed at a tester.  The weapon is triggered by a quantum event, which is essentially random.  If it occurs, the weapon goes off, and the tester dies.  If does not, the weapon does not discharge.   In the Many Worlds approach to quantum events, the tester...or some iteration of the tester...will always survive.  The termination of consciousness will never occur.   It's interesting to think about, but it got me going in another direction.

The obvious limitation of this thought experiment is that the Many Worlds interpretation does not suggest a binary set of options.  It suggests, instead, that from every moment arise a functionally infinite set of variant realities.

For some reason, this got me thinking of Zeno's Paradox.  That classical brain bender, if you recall, notes that in order to travel a distance, you must first travel half that distance.  As any distance can be halved, the number of "halves" you'd have to travel would be infinite...meaning, technically, you shouldn't ever be able to get anywhere.

If the multiverse is as Everett suggests...what is the self?  That's always a fuddler, of course, even in our linear time and space.  Where is the "I" that exists in the flow of time?

But what is self if quantum splits occur from instant to instant?  If from every instant comes not just one but infinite iterations of every possible variant of probability, which one of the umpty-bazillion variants of ourself that pours from the prior moment is the "real" one?

On the one hand, that's an easy one.  Why, we are, of course.

Yet it makes the reality of our being...that we are, that we cohere, that we somehow have integrity as selves...feel even more astounding.  Miraculous, even.