  The fact that we rarely directly observe much quantum uncertainty is often
attributed to decoherence. However, decoherence does not reduce the quantum
uncertainty in the full quantum state. Whether or not it reduces the quantum
uncertainties in observations depends on the yet-unknown rules for getting
observations (and their measures or `probabilities') from the quantum state.
These points are illustrated by a simple toy model with a baseball at 100 miles
per hour, which has the Planck momentum.
