Physics Program Presents
Why Does Nature Like the Square Root of Negative One?
Friday, April 24, 2015
Hegeman 107
Williams Wootters, Williams College
Quantum mechanics is a probabilistic theory, but the way we compute probabilities in quantum mechanics is quite different from what one would expect from, say, rolling dice or tossing coins. To get a quantum probability, we first compute a complex-valued probability amplitude and then square its magnitude. I begin this talk by looking for a deeper explanation of the appearance of probability amplitudes, or “square roots of probability,” in the physical world. It turns out that one can find a potential explanation—it is based on a principle of optimal information transfer—but the argument works only if the square roots are real rather than complex. I then explore a particular theoretical model in which the probability amplitudes are taken to be real and the usual complex phase factor is replaced by a binary quantum variable. One finds that the model leads to a one-parameter generalization of standard quantum theory.
For more information, call 845-758-7302, or e-mail [email protected].
Location: Hegeman 107