[btilly]

There are irreconcilable differences between general relativity and quantum mechanics. A lot of thought has gone into the problem, with little success. But even if someone did come up with something concrete, what then? Try to come up with an interesting experiment that combines gravity and quantum mechanics.

I know of only one, and whether it tests anything at all depends on which interpretation of QM you have. Based on a Geiger counter, either place, or don't place a heavy weight. Try to measure its gravitational pull regardless of what you do. It only measures a pull if you placed the object. If you believe in the Everett interpretation, this says that gravity, at least to a first order approximation, splits with the universe. We do not have sensitive enough instruments to measure non-linear differences from GR.

History tells us that theoretical science done in the absence of experiment is unlikely to lead to useful knowledge.

[martinkallstrom]

What is this experiment called? Any links to read up on?

[atakan_gurkan]

perhaps reading this http://www.hedweb.com/everett/everett.htm

(especially question 7) will help, even though it does not give the name for such an experiment.