  Why Hand Waving? All calculations in books describe oscillations in time. But
real experiments don't measure time. Hand waving is used to convert the results
of a "gedanken time experiment" to the result of a real experiment measuring
oscillations in space. Right hand waving gives the right answer; wrong hand
waving gives the wrong answer. Many papers use wrong handwaving to get wrong
answers. This talk explains how to do it right and also answers the following
questions:
  1. A neutrino which is a mixture of two mass eigenstates is emitted with muon
in the decay of a pion at rest. This is a a "missing mass experiment" where the
muon energy determines the neutrino mass. Why are the two mass states coherent?
  2. A neutrino which is a mixture of two mass eigenstates is emitted at time
t=0. The two mass eigenstates move with different velocities and arrive at the
detector at different times. Why are the two mass states coherent?
  3. A neutrino is a mixture of two overlapping wave packets with different
masses moving with different velocities. Will the wave packets eventually
separate? If yes, when?
