Time viewer

A time viewer is a fictional device that can display events occurring in another time, either the past or (less commonly) the future.

In his short story "The Dead Past" (1956), Isaac Asimov called a similar device a chronoscope, but this is also the name that the Victorian-era scientist Charles Wheatstone gave to his invention for measuring small intervals of time.

Father François Brune, a French Catholic priest and author, related in his book Le nouveau mystère du Vatican (2002) that an Italian priest supposedly invented a time viewer in the 20th century. He called the machine the chronovisor.

In the 1947 novella E for Effort, T. L. Sherred describes a time viewer built by a poor genius who cannot get people to take him seriously. The genius uses his invention to create historical movies which he then shows in his decrepit theater. He is discovered by a Hollywood producer, who is able to exploit the viewer to create first movies, then historical reconstructions, and finally political documentaries. The last part is his undoing, as he exposes every crime committed in the name of patriotism and ideology by world leaders, resulting in the collapse of government, followed by nuclear war.

For the short story "Private Eye" (1949), Henry Kuttner and C.L. Moore (writing together as Lewis Padgett) envision a society in which time-viewing makes it virtually impossible to commit a murder undetected, but which allows pleas of temporary insanity and right of self-defense. The protagonist schemes to provoke an attack by his victim, and then kill the man in (ostensible) self-defense. The murder weapon is an antique scalpel used as a letter opener, whose presence between them is carefully orchestrated by the murderer. The story was dramatized for BBC1 as The Eye, an episode of the science fiction anthology series Out of the Unknown.

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