Time viewer

In science fiction, a time viewer, temporal viewer, or chronoscope is a device that allows another point in time to be observed.^[1] The concept has appeared since the late 19th century, constituting a significant yet relatively obscure subgenre of time travel fiction and appearing in various media including literature, cinema, and television. Stories usually explain the technology by referencing cutting-edge science, though sometimes invoking the supernatural instead. Most commonly only the past can be observed, though occasionally time viewers capable of showing the future appear; these devices are sometimes limited in terms of what information about the future can be obtained. Other variations on the concept include being able to listen to the past but not view it.

One reason authors may choose to write about time viewers rather than time machines is to circumvent the issue of temporal paradoxes. Recurring applications include studying history, solving crimes, and entertainment in the form of displaying historic events to an audience. Because the past includes events as recently as the previous second, privacy may be compromised by such devices; several stories explore the implications thereof. Other stories examine the effects of being observed by onlookers further into the future. An unanticipated influence on past events is a common motif in stories about time viewers, and exploiting this side-effect appears in some stories.

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- Prucher, Jeff (ed.). "time viewer". Brave New Words: The Oxford Dictionary of Science Fiction. p. 244. ISBN 978-0-19-530567-8.
- Prucher, Jeff (ed.). "temporal viewer". Brave New Words: The Oxford Dictionary of Science Fiction. p. 234. ISBN 978-0-19-530567-8.
- Prucher, Jeff (ed.). "chronoscope". Brave New Words: The Oxford Dictionary of Science Fiction. p. 21. ISBN 978-0-19-530567-8.

[1] 
Prucher, Jeff (ed.). "time viewer". Brave New Words: The Oxford Dictionary of Science Fiction. p. 244. ISBN 978-0-19-530567-8.
Prucher, Jeff (ed.). "temporal viewer". Brave New Words: The Oxford Dictionary of Science Fiction. p. 234. ISBN 978-0-19-530567-8.
Prucher, Jeff (ed.). "chronoscope". Brave New Words: The Oxford Dictionary of Science Fiction. p. 21. ISBN 978-0-19-530567-8.

[2] Prucher, Jeff (ed.). "time viewer". Brave New Words: The Oxford Dictionary of Science Fiction. p. 244. ISBN 978-0-19-530567-8.

[3] Prucher, Jeff (ed.). "temporal viewer". Brave New Words: The Oxford Dictionary of Science Fiction. p. 234. ISBN 978-0-19-530567-8.

[4] Prucher, Jeff (ed.). "chronoscope". Brave New Words: The Oxford Dictionary of Science Fiction. p. 21. ISBN 978-0-19-530567-8.

[1]