Overcoming Bias is a well-written group blog that son Robin recently introduced me to. One of the technical topics currently under discussion there is a personal favorite of mine, the Many Worlds Interpretation of quantum mechanics. If I'm mildly fixated on Many Worlds as a good theory, Eliezer Yudkowsky has eaten far too much red meat; his rants are quite entertaining. Here's the conclusion of the latest [1]:

The only reason why many-worlds is not universally acknowledged as a direct prediction of physics which requires magic to violate, is that a contingent accident of our Earth's scientific history gave an entrenched academic position to a phlogiston-like theory which had an unobservable faster-than-light magical "collapse" devouring all other worlds. And many academic physicists do not have a mathematical grasp of Occam's Razor, which is the usual method for ridding physics of invisible angels. So when they encounter many-worlds and it conflicts with their (undermined) intuition that only one world exists, they say, "Oh, that's multiplying entities" - which is just flatly wrong as probability theory - and go on about their daily lives.

I am not in academia. I am not constrained to bow and scrape to some senior physicist who hasn't grasped the obvious, but who will be reviewing my journal articles. I need have no fear that I will be rejected for tenure on account of scaring my students with "science-fiction tales of other Earths". If I can't speak plainly, who can?

So let me state then, very clearly, on behalf of any and all physicists out there who dare not say it themselves: Many-worlds wins outright given our current state of evidence. There is no more reason to postulate a single Earth, than there is to postulate that two colliding top quarks would decay in a way that violates conservation of energy. It takes more than an unknown fundamental law; it takes magic.

The debate should already be over. It should have been over fifty years ago. The state of evidence is too lopsided to justify further argument. There is no balance in this issue. There is no rational controversy to teach. The laws of probability theory are laws, not suggestions; there is no flexibility in the best guess given this evidence. Our children will look back at the fact that we were STILL ARGUING about this in the early 21st-century, and correctly deduce that we were nuts.

We have embarrassed our Earth long enough by failing to see the obvious. So for the honor of my Earth, I write as if the existence of many-worlds were an established fact, because it is. The only question now is how long it will take for the people of this world to update.

(cf. Many Worlds Demystified (1999-10-29) and a host of other pages that allude to that concept — click to search for them ...) - ^z - 2008-05-11

(correlates: Comments on Free Will Facts, TwoDreams, Appliances All the Way Down, ...)