Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

by Philip Ball

As a candidate for a simple unifying principle of quantum mechanics, Časlav Brukner and Anton Zeilinger have offered the notion that every fundamental constituent of a system*4 can only encode one bit of information: it can be this, or it can be that, and nothing else. After all, if it were any more complex than that, would it really be so fundamental? Quantum mechanics then emerges from a mismatch between the actual information-carrying capacity of the basic units of stuff and our beliefs about what they ought to be able to encode. If all the information-bearing potential is used up in answering particular questions, anything else we might try to measure is simply random. If the information content of a particle is all devoted to maintaining a correlation of some property with another particle, say, then the rest is random – and we are forced to make do with probabilities and with statements that are only statistically true.