Spectrophobia Spectrophobia Spectrophobia (from Latin: "spectrum", n. specio, an appearance, form, image of a thing; an apparition, spectre) or catoptrophobia (from Greek κάτοπτρον "kátoptron", "mirror") is a kind of specific phobia involving a morbid fear of mirrors, sometimes related to the fear of ghosts or the undead. This phobia is distinct from eisoptrophobia, which is the fear of one's own reflection. Generally, an individual that deals with spectrophobia has been traumatized in an event where they believe they have seen or heard apparitions or ghosts. The individual could also become traumatized by horror films, television shows, or by nightmares. This fear
Irrational number Consider ; if this is rational, then take "a" = "b" = . Otherwise, take "a" to be the irrational number and "b" = . Then "a" = () = = = 2, which is rational. Although the above argument does not decide between the two cases, the Gelfond–Schneider theorem shows that is transcendental, hence irrational. This theorem states that if "a" and "b" are both algebraic numbers, and "a" is not equal to 0 or 1, and "b" is not a rational number, then any value of "a" is a transcendental number (there can be more than one value