  The many-worlds interpretation of quantum mechanics predicts the formation of
distinct parallel worlds as a result of a quantum mechanical measurement.
Communication among these parallel worlds would experimentally rule out
alternatives to this interpretation. A procedure for ``interworld'' exchange of
information and energy, using only state of the art quantum optical equipment,
is described. A single ion is isolated from its environment in an ion trap.
Then a quantum mechanical measurement with two discrete outcomes is performed
on another system, resulting in the formation of two parallel worlds. Depending
on the outcome of this measurement the ion is excited from only one of the
parallel worlds before the ion decoheres through its interaction with the
environment. A detection of this excitation in the other parallel world is
direct evidence for the many-worlds interpretation. This method could have
important practical applications in physics and beyond.
