  While it is widely believed that gravity should ultimately be treated as a
quantum theory, there remains a possibility that general relativity should not
be quantized. If this is the case, the coupling of classical gravity to the
expectation value of the quantum stress-energy tensor will naturally lead to
nonlinearities in the Schrodinger equation. By numerically investigating time
evolution in the nonrelativistic "Schrodinger-Newton" approximation, we show
that such nonlinearities may be observable in the next generation of molecular
interferometry experiments.
