{"id":4679,"date":"2010-05-10T12:16:23","date_gmt":"2010-05-10T12:16:23","guid":{"rendered":"http:\/\/scienceblogs.com\/principles\/2010\/05\/10\/the-problem-of-quantum-moderat\/"},"modified":"2010-05-10T12:16:23","modified_gmt":"2010-05-10T12:16:23","slug":"the-problem-of-quantum-moderat","status":"publish","type":"post","link":"http:\/\/chadorzel.com\/principles\/2010\/05\/10\/the-problem-of-quantum-moderat\/","title":{"rendered":"The Problem of (Quantum) Moderation: On Many Worlds"},"content":{"rendered":"

I’ve written before about the problem of having in-between views on controversial subjects in blogdom. This is something that also comes up in Jessica’s excellent entry on online culture<\/a>, and has been scientifically demonstrated<\/a> in political contexts.<\/p>\n

I’m somewhat bemused, then, to see the same thing happen in a physics context. A while back, I got an email asking about quantum foundations that read in part:<\/p>\n

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I’m very keen to understand why you and Andrew Thomas<\/a> reject [the Many-Worlds Interpretation of QM].
\nI’d be very happy if you’d take a few minutes to try to describe why you think MWI is wrong and also what you think is more likely to be true and why.<\/p>\n<\/blockquote>\n

(I added the link, for context.)<\/p>\n

This is kind of amusing to me, as I have previously taken some flak here for being excessively pro<\/em>-MWI, in the view of some readers. I just can’t win.<\/p>\n

My real view is, alas, kind of wishy-washy: I’m agnostic about quantum interpretations, mostly because as far as we know, they’re all meta-theories, not proper scientific theories. There is no experimental test known that clearly favors one interpretation over another, so which one you like is ultimately a question of taste. They’re kind of fun to talk about, but absent a way to distinguish between them, they’re not more than that.<\/p>\n

Another way of saying that would be to say that I subscribe to the “Shur Up and Calculate” interpretation (a phrase that apparently originates with David Mermin in a 1989 column in Physics Today<\/cite>, so please don’t attribute it to Feynman). The concrete predictions of quantum physics are tested to something like 14 decimal places, and the choice of interpretation doesn’t affect any of those results, so just focus on what works, and leave the meta-theorizing to philosophers.<\/p>\n

The clearest statement I have about what Many-Worlds is really about is this old post on MWI and decoherence<\/a>, which can be found in a much cuter canine version in How to Teach Physics to Your Dog<\/cite><\/a> (available wherever books are sold, hint hint). That said, here are a few general things I will say about it:<\/p>\n

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