Does nature impose limits on what we can know? But why?
|September 12, 2013||Posted by News under News, Physics|
From an article in Nature, on a variety of efforts to come to terms with the quantum world:
… entanglement and all the other strange phenomena of quantum theory are not a completely new form of physics. They could just as easily arise from a theory of knowledge and its limits.
To get a better sense of how, Fuchs has rewritten standard quantum theory into a form that closely resembles a branch of classical probability theory known as Bayesian inference, which has its roots in the eighteenth century. In the Bayesian view, probabilities aren’t intrinsic quantities ‘attached’ to objects. Rather, they quantify an observer’s personal degree of belief of what might happen to the object. Fuchs’ quantum Bayesian view, or QBism (pronounced ‘cubism’), is a framework that allows known quantum phenomena to be recovered from new axioms that do not require mathematical constructs such as wavefunctions. QBism is already motivating experimental proposals, he says. Such experiments might reveal, for example, new, deep structures within quantum mechanics that would allow quantum probability laws to be re-expressed as minor variations of standard probability theory.
Knowledge — which is typically measured in terms of how many bits of information an observer has about a system — is the focus of many other approaches to reconstruction, too. As physicists Caslav Brukner and Anton Zeilinger of the University of Vienna put it, “quantum physics is an elementary theory of information”. Meanwhile, physicist Marcin Pawlowski at the University of Gdansk in Poland and his colleagues are exploring a principle they call ‘information causality’. This postulate says that if one experimenter (call her Alice) sends m bits of information about her data to another observer (Bob), then Bob can gain no more than m classical bits of information about that data — no matter how much he may know about Alice’s experiment.
Well, if a theory of information underlies the universe, then intelligence must also, not?