|
|
|
||||||||
State Reflects Observer's Knowledge
This interpretation says that the quantum state which we manipulate in quantum mechanics reflects only the observer's knowledge about the system and not the system itself. The wavefunction is not a physical thing, but represents our knowledge of where a particle is. Instead of just being a probability density function as we have in classical physics, the wavefunction is a density represented by a complex amplitude. The absolute square of the amplitude gives the probability to find the particle at any given location. Given our knowledge of the wavefunction at one instant, we can propagate our knowledge forward in time using the Schrodinger equation (or Klein-Gordon, or Dirac, as appropriate). This wavefunction never collapses. When we make a measurement it only alters our knowledge of the state of the particle. Our new knowledge is representable by another wavefunction, one that is more localized than the one representing our previous knowledge. It is impossible to obtain more than half the information about a particle's state in a single measurement, and making a measurement alters the state so that any previous information we had about the other half is now no longer applicable. We can measure the position of a particle, but only at the expense of randomizing its momentum, which makes our previous knowledge of its momentum out of date. It is also allowable to have partial knowledge about the position and partial knowledge about the momentum, but the sum of our knowledge is never more than half the total. This restriction to half the total knowledge is the essence of Heisenberg's uncertainty principle.Pros
Quantum mechanics might be recast more in terms of information theory.Might be possible to eliminate the special role of the observer by creating a theory that gives the knowledge of any possible observer and how they are related to one another in a consistent way.
Cons
Doesn't explain why our knowledge is a complex amplitude rather than a probability.
Back to Interpretations
Back to Michael Gibbs' Home Page