“The scientific study of allegedly psychic phenomena has now been going on for more than a century. Investigators in this field of psychic research have discovered some cases of fraud, and found that some apparently paranormal events can in fact be explained by normal causes. But there remains a large body of evidence that seems to defy explanation in terms of any known physical principles. Numerous experiments designed to test for so-called extra-sensory perception have yielded positive results with odds against chance coincidence of thousands, millions or even billions to one.”