Tuesday, May 21, 2013

Presbyterians in the Quantum Realm

Yesterday, my afternoon wanderings took me to a public library, as my younger son rocked out across the street in his drum lesson.  I settled in and began casually flipping through the latest Scientific American, and was immediately drawn to an article on the latest theoretical exploration of the quantum realm.

This is what Presbyterian pastors do when they have a few minutes to themselves.  Which is why it's best to keep us busy all the time, I suppose.

New Exciting Approach to Quantum Mechanics, announced the teaser on the cover, and given my fascination with that topic, I dove right in.   The article was written by Hans Christian von Baeyer, a theoretical physicist, and it...well...it was fascinating for a variety of reasons.

It describes what von Baeyer describes, in what in my mind's ear is an aristocratic Austrian accent, an approach called "QBism."   No, we're not talking Picasso here.  It's short for what is being called the "Quantum Bayesian" approach of that odd branch of science.

This was, of course, absolutely tantalizing.

Following the completion of my forthcoming book on the Many Worlds interpretation of quantum theory and theology, I read Thomas Bayes' treatise this last year.  No, not the one in which Bayes established the foundation for Bayes Theorem, the equation that underlies all modern probability theory.  The first one, the one that inspired that theory.  Bayes, a Presbyterian minister, got his inspiration for probability theory from a theological exploration of the goodness of God.

Probability theory and quantum physics...particularly of the Many Worlds variety...are two great tastes that taste great together.   Probability is particularly useful as a measure for nonlinear ethical behavior and moral norms in a multiverse.  Or at least, that is where instinct seems to be leading.

But what was most interesting about this article was that it seems to be saying that the quantum realm doesn't actually exist at all.  von Baeyer's "QBist" approach suggests that all of the quantum realm is either just a mathematical construct or completely imaginary.

Capable of shaping reality, yes.  Real?  Well, sort of.  And sort of not.

Huh.  So at it's most fundamental level, reality isn't real?  Errr.

I think I'll stick with the Many Worlds approach for the time being.  But Bayes?  Bayes is still worth exploring.

Few things are more fascinating than a Presbyterian with time on their hands.


  1. "Probability is particularly useful as a measure for..."

    Fill in the blank, please. I'd like to believe I was really tracking with you until I fell off the end of that sentence!

    Intriguing thoughts, David! Wish I had more time to dive into these myself! My wife used to tease me for reading books like Physics for Entertainment by Yakov Perelman on my vacation time.

  2. Done and done. Have to watch out for those free roaming sentence fragments! Thanks for noticing it!