In 1988, Aharonov, David Albert, and Lev Vaidman published their theory of weak values. This work was motivated by Aharonov's long-time quest to experimentally verify his theory that apparently random events in quantum mechanics are caused by events in the future (two-state vector formalism). Verifying a present effect of a future cause requires a measurement, which would ordinarily destroy coherence and ruin the experiment. He and his colleagues claim that they were able to use weak measurements and verify the present effect of the future cause. Working with Aharon Casher, they predicted the Aharonov–Casher effect, the electrodynamic dual of the Aharonov–Bohm effect with magnetic dipoles and charges.