Clairvoyance is the E.S.P. ability to sense by way of the powers of the mind rather than through the physical senses. For example, a person with clairvoyance may be able to sense what is occuring in the next room as though she or he had 'X-ray vision', or she or he might suddenly sense an event occuring thousands of miles away. Legitimate scientific studies of clairvoyance have netted mixed results, not enough to prove or disprove it. However, clairvoyance remains a popular psionic power in SF.