{{Short description|Device in science fiction}} {{good article}} In [[science fiction]], a '''time viewer''', '''temporal viewer''', or '''chronoscope''' is a device that allows another point in time to be observed.<ref>{{multiref2|{{Cite book |title=[[Brave New Words: The Oxford Dictionary of Science Fiction]] |isbn=978-0-19-530567-8 |editor-last=Prucher |editor-first=Jeff |pages=244 |language=en |chapter=time viewer |chapter-url=https://books.google.com/books?id=iYzi8m8FbEsC&pg=PA244}}|{{Cite book |title=[[Brave New Words: The Oxford Dictionary of Science Fiction]] |isbn=978-0-19-530567-8 |editor-last=Prucher |editor-first=Jeff |pages=234 |language=en |chapter=temporal viewer |chapter-url=https://books.google.com/books?id=iYzi8m8FbEsC&pg=PA234}}|{{Cite book |title=[[Brave New Words: The Oxford Dictionary of Science Fiction]] |isbn=978-0-19-530567-8 |editor-last=Prucher |editor-first=Jeff |pages=21 |language=en |chapter=chronoscope |chapter-url=https://books.google.com/books?id=iYzi8m8FbEsC&pg=PA21}}}}</ref> 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 machine]]s is to circumvent the issue of [[temporal paradox]]es. 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.
== Concept == In its most basic form, a time viewer is a device that only allows the observation of the past.<ref name="Baxter">{{Cite magazine |last=Baxter |first=Stephen |author-link=Stephen Baxter (author) |date=Autumn 2000 |title=The Technology of Omniscience: Past Viewers in Science Fiction |magazine=[[Foundation (journal)|Foundation]] |publisher=[[Science Fiction Foundation]] |issue=80 |pages=97–107 |issn=0306-4964}}</ref>{{Rp|pages=97}} Unlike with a [[time machine]], the user is not transported from one moment in time to another.<ref name="SFETimeViewer">{{Cite encyclopedia |year=2022 |title=Time Viewer |encyclopedia=[[The Encyclopedia of Science Fiction]] |url=https://sf-encyclopedia.com/entry/time_viewer |access-date=2022-07-26 |last=Langford |first=David |author-link=David Langford |editor-last=Clute |editor-first=John |editor-link=John Clute |edition=4th |editor3-link=Graham Sleight |editor3-first=Graham |editor3-last=Sleight |editor2-first=David |editor2-last=Langford |editor2-link=David Langford}}</ref><ref>{{Cite encyclopedia |year=2017 |title=Time Machine |encyclopedia=[[The Encyclopedia of Science Fiction]] |url=https://sf-encyclopedia.com/entry/time_machine |access-date=2022-07-27 |author-link=Peter Nicholls (writer) |editor-last=Clute |editor-first=John |editor-link=John Clute |edition=4th |author2-last=Langford |author2-first=David |author1-last=Nicholls |editor3-link=Graham Sleight |editor3-first=Graham |editor3-last=Sleight |editor2-first=David |author1-first=Peter |author2-link=David Langford |editor2-last=Langford |editor2-link=David Langford}}</ref> Under the strictest definition it cannot alter the past;<ref name="Baxter" />{{Rp|pages=97}}<ref name="SFETimeViewer" /> however, the unexpected discovery that the device does indeed affect the past is a common motif.<ref name="Baxter" />{{Rp|pages=99}}<ref name="SFETimeViewer" /> Variations on the concept where the future rather than the past is observed are more uncommon but nevertheless appear in multiple works.<ref name="SFETimeViewer" /><ref name="WebbTimeViewers">{{Cite book |last=Webb |first=Stephen |author-link=Stephen Webb (scientist) |title=All the Wonder that Would Be: Exploring Past Notions of the Future |date=2017 |publisher=Springer |isbn=978-3-319-51759-9 |series=Science and Fiction |pages=127–128 |language=en |chapter=Time Viewers |doi=10.1007/978-3-319-51759-9_5 |chapter-url=https://books.google.com/books?id=TVPJDgAAQBAJ&pg=PA127}}</ref>{{Rp|pages=128}} Another variation involves listening to the past rather than viewing it.<ref name="Baxter" />{{Rp|pages=97–98}}<ref name="SFETimeViewer" />
=== Methods === In-universe justifications for the ability to observe the past vary, typically corresponding to contemporary scientific developments;<ref name="Baxter" />{{Rp|pages=98}} time viewers exploit impressions on the [[Luminiferous aether|aether]] in the 1926 novel ''[[The Vicarion]]'' by [[Gardner Hunting]],<ref name="Nahin2001">{{Cite book |last=Nahin |first=Paul J. |author-link=Paul J. Nahin |title=Time Machines: Time Travel in Physics, Metaphysics, and Science Fiction |date=1999 |publisher=Springer |others=Foreword by [[Kip S. Thorne]] |isbn=978-0-387-98571-8 |edition=Second |pages=57–60 |language=en |chapter=Ways to Avoid Paradoxes |orig-date=1993 |chapter-url=https://archive.org/details/timemachinestime0000nahi_m8y6/page/56/mode/2up}}</ref>{{Rp|pages=58}} exotic [[neutrino]] properties in the 1956 short story "[[The Dead Past]]" by [[Isaac Asimov]],<ref name="Baxter" />{{Rp|pages=104–105}} and [[Wormhole|wormholes]] in the 2000 novel ''[[The Light of Other Days]]'' by [[Stephen Baxter (author)|Stephen Baxter]] and [[Arthur C. Clarke]].<ref name="Broderick" />{{Rp|pages=158–159}} A common explanation involves the finite [[speed of light]] and astronomical distances; this method appears in the 1935 short story "[[The Space Lens]]" by [[Donald A. Wollheim]], among others.<ref name="SFETimeViewer" /> A variation that appears in the 1966 short story "[[Light of Other Days]]" by [[Bob Shaw]] (later included in the 1972 [[fix-up]] novel ''[[Other Days, Other Eyes]]'') is using [[slow glass]] whose high [[refractive index]] means light takes years to pass through it.<ref name="Baxter" />{{Rp|pages=105}}<ref name="WebbTimeViewers" />{{Rp|pages=127–128}}<ref name="SimsFrankensteinDreams" />{{Rp|pages=100–101}} [[Supernatural]] explanations also occur in works like the 1925 short story "[[A View from a Hill (short story)|A View From a Hill]]" by [[M. R. James]], where a pair of binoculars are [[Incantation|enchanted]] to show the past, and the 1976 short story "[[Balsamo's Mirror]]" by [[L. Sprague de Camp]], where the titular mirror allows a present-day person to view the world through the eyes of one from the past.<ref name="Baxter" />{{Rp|pages=100}}<ref name="SimsFrankensteinDreams" />{{Rp|pages=100}}
== History == [[File:The Ghost of Slumber Mountain - 1918 - square poster.jpg|alt=Poster for The Ghost of Slumber Mountain|thumb|''[[The Ghost of Slumber Mountain]]'' (1918) had the first cinematic depiction of a time viewer.]]
The earliest known example of a fully fledged time viewer in fiction appears in the 1882 short story "[[L'historioscope]]" by [[Eugène Mouton]] in the form of an electrical telescope, though it was prefigured by a couple of proto-variations on the concept;<ref name="SFETimeViewer" /><ref name="SimsFrankensteinDreams" />{{Rp|pages=100}}<ref>{{Cite encyclopedia |year=2018 |title=Mouton, Eugène |encyclopedia=[[The Encyclopedia of Science Fiction]] |url=https://sf-encyclopedia.com/entry/mouton_eugene |access-date=2022-07-27 |last=Clute |first=John |author-link=John Clute |editor-last=Clute |editor-first=John |editor-link=John Clute |edition=4th |editor3-link=Graham Sleight |editor3-first=Graham |editor3-last=Sleight |editor2-first=David |editor2-last=Langford |editor2-link=David Langford}}</ref><ref>{{cite book |last1=Moure |first1=José |url=https://library.oapen.org/viewer/web/viewer.html?file=/bitstream/handle/20.500.12657/32716/607790.pdf |title=Screens: From Materiality to Spectatorship–A Historical and Theoretical Reassessment |date=2025 |publisher=Taylor & Francis |isbn=978-90-4853-169-1 |editor-last=Chateau |editor-first=Dominique |pages=56–57, 280n31 |language=en |chapter=Archaic Paradigms of the Screen and Its Images |editor-last2=Moure |editor-first2=José}}</ref> in the 1872 work ''[[Recits de l'infini]]'' (which later turned into the 1887 novel ''[[Lumen (novel)|Lumen]]'') by [[Camille Flammarion]] a spirit accomplishes the same effect by travelling [[faster than light]], and the titular device in the 1873 short story "The Automaton Ear" by [[Florence McLandburgh]] enables listening to the past.<ref name="SFETimeViewer" /><ref name="SimsFrankensteinDreams">{{Cite book |last=Sims |first=Michael |author-link=Michael Sims |title=Frankenstein Dreams: A Connoisseur's Collection of Victorian Science Fiction |date=2017 |publisher=Bloomsbury Publishing USA |isbn=978-1-63286-042-2 |pages=99–101 |language=en |chapter=Florence McLandburgh |chapter-url=https://books.google.com/books?id=rZyZDgAAQBAJ&pg=PA100}}</ref>{{Rp|pages=100–101}}<ref>{{Cite book |last=Selzer |first=Adam |title=Graceland Cemetery: Chicago Stories, Symbols, and Secrets |date=2022-08-09 |publisher=University of Illinois Press |isbn=978-0-252-05342-9 |pages=251 |language=en |chapter=Florence McLandburgh: Early Science Fiction Author |author-link=Adam Selzer |chapter-url=https://books.google.com/books?id=yfN3EAAAQBAJ&pg=PA251}}</ref>{{Rp|pages=251}}
In film, the first time viewer appeared in the 1918 film ''[[The Ghost of Slumber Mountain]]''.<ref name="SFETimeViewer" /> The concept has appeared regularly in works of fiction ever since, creating a sub-genre within [[time travel fiction]], but remained comparatively obscure.<ref name="Baxter" />{{Rp|pages=97}}<ref name="Nahin2001" />{{Rp|pages=57–58}}<ref name="Broderick">{{Cite book |last=Broderick |first=Damien |url=https://books.google.com/books?id=5RKiDwAAQBAJ |title=The Time Machine Hypothesis: Extreme Science Meets Science Fiction |date=2019 |publisher=Springer |isbn=978-3-030-16178-1 |series=Science and Fiction |pages=71, 158–160 |language=en |author-link=Damien Broderick}}</ref>{{Rp|pages=71}}<ref name="StablefordTimeTravel" />{{Rp|pages=532–533}}
== Narrative function == Science fiction author [[Stephen Baxter (author)|Stephen Baxter]] identifies several different ways time viewers are used in fiction. The most basic premise is of the time viewer as simply a "neat gadget", with a common variation being something going wrong, typically the past being unintentionally altered. Changing the past on purpose is another recurring application. According to Baxter, the wider implications of the existence of time viewers are sometimes explored in [[hard science fiction]] with a [[PEST analysis|PEST (political, economic, social, and technical) analysis]].<ref name="Baxter" />{{Rp|pages=98–99, 101}}
Several authors consider time viewers to be inherently more plausible than time machines. Science fiction author [[Damien Broderick]] says that "using a time viewer is in essence no more absurd than watching a movie made 50 years ago" since the past cannot be affected by it.<ref name="Broderick" />{{Rp|pages=71}} Baxter similarly says that time viewers are more extrapolation than fantasy, comparing them to [[Archaeology|archaeological research]].<ref name="Baxter" />{{Rp|pages=97}} For this reason, science writer [[Paul J. Nahin]] and physicist [[Stephen Webb (scientist)|Stephen Webb]] say that a benefit for writers is being able to write time travel stories without needing to consider the possibility of [[time paradoxes]];<ref name="WebbTimeViewers" />{{Rp|pages=128}}<ref name="Nahin2001" />{{Rp|pages=57–58}} Nahin nevertheless notes that interacting with the past via a time machine, or even affecting it, does not necessarily cause paradoxes.<ref name="Nahin2001" />{{Rp|pages=57}}
== Themes ==
=== Studying history === Time viewers are sometimes used to observe moments in history that are similarly popular destinations for [[time travel in fiction]], one example being the [[crucifixion of Jesus]] in the 1904 novel ''Around a Distant Star'' by {{Interlanguage link|Jean Delaire (author)|lt=Jean Delaire|qid=Q66429439}}.<ref name="StablefordTimeTravel">{{Cite book |last=Stableford |first=Brian M. |title=[[Science Fact and Science Fiction: An Encyclopedia]] |date=2006 |publisher=Taylor & Francis |isbn=978-0-415-97460-8 |pages=532–535 |language=en |chapter=Time Travel |author-link=Brian Stableford |chapter-url=https://books.google.com/books?id=uefwmdROKTAC&pg=PA532}}</ref>{{Rp|pages=534}}<ref>{{Cite encyclopedia |year=2022 |title=Delaire, Jean |encyclopedia=[[The Encyclopedia of Science Fiction]] |url=https://sf-encyclopedia.com/entry/delaire_jean |access-date=2023-02-04 |author-link=Peter Nicholls (writer) |editor-last=Clute |editor-first=John |editor-link=John Clute |edition=4th |author2-last=Clute |author2-first=John |last3=Ashley |first3=Mike |author1-last=Nicholls |editor3-link=Graham Sleight |editor3-first=Graham |editor3-last=Sleight |editor2-first=David |author1-first=Peter |author2-link=John Clute |editor2-last=Langford |editor2-link=David Langford |author3-link=Mike Ashley (writer)}}</ref> In the 1956 short story "[[The Dead Past]]" by [[Isaac Asimov]], a historian is excited to use a time viewer to study [[ancient Carthage]], only to find out that the device is limited to viewing the most recent 120 years,<ref name="WebbTimeViewers" />{{Rp|pages=127}} and a historian uses a time viewer to read the contents of the [[Library of Alexandria]] in the 1980 short story "One Time in Alexandria" by [[Donald Franson]].<ref>{{Cite book |last=Nahin |first=Paul J. |author-link=Paul J. Nahin |title=Time Machines: Time Travel in Physics, Metaphysics, and Science Fiction |date=1999 |publisher=Springer |others=Foreword by [[Kip S. Thorne]] |isbn=978-0-387-98571-8 |edition=Second |pages=283 |language=en |chapter=Changing the Past vs. Affecting It |orig-date=1993 |chapter-url=https://archive.org/details/timemachinestime0000nahi_m8y6/page/282/mode/2up}}</ref>{{Rp|pages=283}}
In the 1938–1939 ''[[Trumpets from Oblivion]]'' series by [[Henry Bedford-Jones]], a time viewer allows scientists to discover the explanations for various myths,<ref name="SFETimeViewer" /><ref>{{Cite encyclopedia |year=2019 |title=Blue Book Magazine, The |encyclopedia=[[The Encyclopedia of Science Fiction]] |url=https://sf-encyclopedia.com/entry/blue_book_magazine_the |access-date=2022-07-29 |last=Ashley |first=Mike |author1-link=Mike Ashley (writer) |editor-last=Clute |editor-first=John |editor-link=John Clute |edition=4th |editor2-link=David Langford |editor3-link=Graham Sleight |editor3-first=Graham |editor3-last=Sleight |editor2-first=David |editor2-last=Langford}}</ref> and two war veterans use a time viewer to create historical films in order to dispel public misconceptions about the [[American Revolution]] and the [[American Civil War]] in the 1947 novelette "[[E for Effort]]" by [[T. L. Sherred]].<ref name="Baxter" />{{Rp|pages=103}}<ref name="WebbTimeViewers" />{{Rp|pages=127}} Revealing the truth about historical events also appears in the 1953 novel ''[[Childhood's End]]'' by [[Arthur C. Clarke]], where [[Alien invasion|alien invaders]] show humanity that our religions are false.<ref name="Baxter" />{{Rp|pages=102–103}}
[[Astronomy]] is similarly studied in the 1969 novel ''[[Macroscope (novel)|Macroscope]]'' by [[Piers Anthony]] and the 1999 short story "[[Hatching the Phoenix]]" by [[Frederik Pohl]]. In the former the [[formation of the Solar System]] is studied, while in the latter observations are made of a world that has since been destroyed by a supernova.<ref name="SFETimeViewer" /> Scientists in the 2000 novel ''[[The Light of Other Days]]'' by [[Stephen Baxter (author)|Stephen Baxter]] and Arthur C. Clarke use time viewer technology to study the entire [[history of life]] on Earth.<ref name="Broderick" />{{Rp|pages=160}}
=== Crimefighting === An early instance of a time viewer being used to solve crimes is the 1926 novel ''[[The Vicarion]]'' by [[Gardner Hunting]], as events leading up to a crime can be uncovered in reverse after the fact.<ref name="Baxter" />{{Rp|pages=101–102}}<ref name="SFETimeViewer" /> Later examples include the 1948 short story "[[Private Eye (short story)|Private Eye]]" by [[Henry Kuttner]] and [[C. L. Moore]] (writing jointly as "[[Lewis Padgett]]"), which revolves around a man planning a murder in such a way that the use of a time viewer by the authorities would not reveal his guilt,<ref name="Baxter" />{{Rp|pages=103–104}} and the 2006 film ''[[Déjà Vu (2006 film)|Déjà Vu]]'', where the device shows events with a four-day delay which cannot be adjusted and there is consequently only one opportunity to view any given event.<ref name="SFETimeViewer" /><ref>{{Cite encyclopedia |year=2022 |title=Déjà Vu |encyclopedia=[[The Encyclopedia of Science Fiction]] |url=https://sf-encyclopedia.com/entry/deja_vu |access-date=2022-07-28 |last=Nicholls |first=Jack |author1-link=<!-- No article at present (July 2022); son of Peter Nicholls (writer) --> |editor-last=Clute |editor-first=John |editor-link=John Clute |edition=4th |editor2-link=David Langford |editor3-link=Graham Sleight |editor3-first=Graham |editor3-last=Sleight |editor2-first=David |editor2-last=Langford}}</ref>
=== Entertainment === The 1926 novel ''The Vicarion'' by Gardner Hunting is an early example of time viewers being used for entertainment;<ref name="SFETimeViewer" /> in the story, moments from history are shown in movie theaters to great public interest. Baxter compares the in-story effects on society, where "mass addiction to this vibrant spectacle quickly overtakes the public", to the later real-world advent of the [[television]].<ref name="Baxter" />{{Rp|pages=101–102}} This theme recurs in the 1947 novelette "E for Effort" by T. L. Sherred, though in that story the public is unaware that the films are not conventional movie productions.<ref name="WebbTimeViewers" />{{Rp|pages=127}}
=== Privacy and espionage === A number of works explore the implications of being capable of remotely viewing the recent past—potentially as recent as less than a second ago—on [[privacy]].<ref name="Baxter" />{{Rp|pages=101–102, 104–105}}<ref name="SFETimeViewer" /><ref name="WebbTimeViewers" />{{Rp|pages=127–128}}<ref>{{Cite book |last=Langford |first=David |title=Up Through an Empty House of Stars |date=2003 |publisher=Wildside Press LLC |isbn=978-1-59224-055-5 |pages=266 |language=en |chapter=Arthur C. Clarke and Stephen Baxter – ''The Light of Other Days'' (2000) |author-link=David Langford |chapter-url=https://books.google.com/books?id=k4qgRSodu80C&pg=PA266}}</ref>{{Rp|pages=266}} In the 1956 short story "The Dead Past" by Isaac Asimov, its use is suppressed by the government for this reason.<ref name="Baxter" />{{Rp|pages=104–105}}<ref name="WebbTimeViewers" />{{Rp|pages=127}} In the 1972 [[fix-up]] novel ''[[Other Days, Other Eyes]]'' by [[Bob Shaw]], particles of the [[slow glass]] that captures images are spread all over to enable [[mass surveillance]].<ref name="SFETimeViewer" /> The 1976 short story "[[I See You (short story)|I See You]]" by [[Damon Knight]] posits that the complete loss of privacy resulting from universal access to a time viewer would usher in a [[utopia]] free from deceit and embarrassment.<ref name="Baxter" />{{Rp|pages=104}}<ref name="SFETimeViewer" />
[[Espionage]] applications appeared early; in the 1926 short story "The Time Eliminator" by pseudonymous author "Kaw", the United States government uses a time viewer to spy on a meeting of foreign leaders.<ref name="Baxter" />{{Rp|pages=101}}<ref name="SFETimeViewer" /> The realization that it can be put to this use triggers war to ensure that it does not in the 1947 novelette "E for Effort" by T. L. Sherred.<ref name="Baxter" />{{Rp|pages=103}}<ref name="SFETimeViewer" />
The implication that just as we are watching the past, people in the future are surely watching us is explored in the 1951 short story "[[Operation Peep]]" by [[John Wyndham]]. In order to regain privacy, people eventually resort to shining bright lights to effectively blind the future onlookers.<ref name="Baxter" />{{Rp|pages=102}} In the 1953 short story "[[The Parasite (Clarke short story)|The Parasite]]" by Arthur C. Clarke, the realization that he is constantly being watched by a future being eventually drives a man to suicide.<ref name="Baxter" />{{Rp|pages=102}} The intensity of observation from the future is measured in the 1981 short story "[[The Final Days (short story)|The Final Days]]" by [[David Langford]] to gauge an individual's importance to the world of the future.<ref name="SFETimeViewer" />
=== Altering the past === Several stories reveal that the time viewer can not only observe the past but influence it.<ref name="Baxter" />{{Rp|pages=99}} In the 1951 short story "[[The Biography Project]]" by [[H. L. Gold]], being constantly watched drives [[Isaac Newton]] insane.<ref name="Baxter" />{{Rp|pages=99}} In the [[Satire|satirical]] 1948 short story "[[The Brooklyn Project]]" by [[William Tenn]], the scientists in charge insist that the past is immutable even as they and their surroundings undergo drastic changes, because from their new perspective those alterations have always been in place.<ref name="Baxter" />{{Rp|pages=99}}<ref>{{Cite book |last=Gleick |first=James |title=[[Time Travel: A History]] |date=2016 |publisher=Knopf Doubleday Publishing Group |isbn=978-0-307-90880-3 |pages=205 |language=en |chapter=Backward |author-link=James Gleick |chapter-url=https://books.google.com/books?id=wz5mCwAAQBAJ&pg=PA205}}</ref>{{Rp|pages=205}}<ref>{{Cite web |last=D'Ammassa |first=Don |author-link=Don D'Ammassa |title=William Tenn |url=http://www.dondammassa.com/ztenn.htm |access-date=2022-07-29 |website=www.dondammassa.com |quote="The Brooklyn Project" however is one of my favorite time travel stories. Despite warnings that changes wrought in the past would be undetectable because people in the present would assume they had always been the case, an experiment leads to the replacement of humanity by intelligent amoebas.}}</ref>
In some stories, the past is changed intentionally.<ref name="Baxter" />{{Rp|pages=99}} Humorous depictions include the 1972 short story "[[The Greatest Television Show on Earth]]" by [[J. G. Ballard]], where a TV company hires additional people as soldiers to make the [[Battle of Waterloo]] live up to viewers' expectations, and the 1967 novel ''[[The Technicolor Time Machine]]'' by [[Harry Harrison (writer)|Harry Harrison]], which implies that the [[Norse colonization of North America|Viking settlement]] of [[Vinland]] only happened because Hollywood wanted to make a movie about it.<ref name="Baxter" />{{Rp|pages=99}} A more serious treatment appears in the 1996 novel ''[[Pastwatch: The Redemption of Christopher Columbus]]'' by [[Orson Scott Card]]:<ref name="Baxter" />{{Rp|pages=99}} after discovering that the past has previously been tampered with, a team of future scientists seek to undo the harm caused by [[Christopher Columbus]]'s [[Voyages of Christopher Columbus|voyages]] to the [[New World]], even though it would mean their timeline would be obliterated.<ref>{{Cite book |last=Westfahl |first=Gary |title=Science Fiction Writers: Critical Studies of the Major Authors from the Early Nineteenth Century to the Present Day |date=1999 |publisher=[[Charles Scribner's Sons]] |isbn=0-684-80593-6 |editor-last=Bleiler |editor-first=Richard |editor-link=Richard Bleiler |edition=2nd |location=New York |pages=187–188 |chapter=Orson Scott Card |oclc=40460120 |author-link=Gary Westfahl |chapter-url=https://archive.org/details/sciencefictionwr0000unse/page/187/mode/2up}}</ref>{{Rp|pages=187–188}}<ref>{{Cite book |last=Leonard |first=Elisabeth Anne |title=The Cambridge Companion to Science Fiction |date=2003 |publisher=Cambridge University Press |isbn=978-0-521-01657-5 |editor-last=James |editor-first=Edward |editor-link=Edward James (historian) |pages=258–261 |language=en |chapter=Race and Ethnicity in Science Fiction |editor-last2=Mendlesohn |editor-first2=Farah |editor-link2=Farah Mendlesohn |chapter-url=https://books.google.com/books?id=55wUHXiay-gC&pg=PA258}}</ref>{{Rp|pages=258–261}}<ref>{{Cite book |last=Buker |first=Derek M. |title=The Science Fiction and Fantasy Readers' Advisory: The Librarian's Guide to Cyborgs, Aliens, and Sorcerers |date=2002 |publisher=[[American Library Association]] |isbn=978-0-8389-0831-0 |pages=54 |chapter=Time Travel |chapter-url=https://archive.org/details/sciencefictionfa00buke_0/page/54/mode/2up}}</ref>{{Rp|pages=54}}
== Future time viewers == Rarely, time viewers may be depicted as allowing observation of the future rather than the past.<ref name="SFETimeViewer" /><ref name="WebbTimeViewers" />{{Rp|pages=128}} Stephen Webb argues that viewing the future has more in common with [[fantasy]] and [[fortune-telling]] than with [[science fiction]],<ref name="WebbTimeViewers" />{{Rp|pages=128}} and [[David Langford]] notes in ''[[The Encyclopedia of Science Fiction]]'' that the possibility of viewing the future has implications for the question of [[free will]] versus [[determinism]].<ref name="SFETimeViewer" />
Devices capable of viewing the future have been portrayed in various ways. In the 1922 short story "[[The Prophetic Camera]]" by [[Lance Sieveking]], the titular camera can take pictures an adjustable amount of time into the future,<ref name="SFETimeViewer" /><ref>{{Cite book |last=Bleiler |first=Everett Franklin |title=[[Science-fiction, the Early Years: A Full Description of More Than 3,000 Science-fiction Stories from Earliest Times to the Appearance of the Genre Magazines in 1930 : with Author, Title, and Motif Indexes]] |date=1990 |publisher=Kent State University Press |isbn=978-0-87338-416-2 |pages=685 |language=en |chapter=Sieveking, L[ancelot] de Giberne (1896–1972) |author-link=E. F. Bleiler |chapter-url=https://books.google.com/books?id=KEZxhkG5eikC&pg=PA685}}</ref>{{Rp|pages=685}} while in the 1960 ''[[The Twilight Zone (1959 TV series)|The Twilight Zone]]'' episode "[[A Most Unusual Camera]]" the device only has a reach of five minutes into the future.<ref name="Nahin2001" />{{Rp|pages=60}} In the 1955 novel ''[[The Pleasures of a Futuroscope]]'' by [[Lord Dunsany]], the device reveals a future [[nuclear holocaust]].<ref name="SFETimeViewer" /><ref>{{Cite encyclopedia |year=2022 |title=Dunsany, Lord |encyclopedia=[[The Encyclopedia of Science Fiction]] |url=https://sf-encyclopedia.com/entry/dunsany_lord |access-date=2022-07-26 |author-link=John Clute |editor-last=Clute |editor-first=John |editor-link=John Clute |edition=4th |author2-last=Langford |author2-first=David |author1-last=Clute |editor3-link=Graham Sleight |editor3-first=Graham |editor3-last=Sleight |editor2-first=David |author1-first=John |author2-link=David Langford |editor2-last=Langford |editor2-link=David Langford}}</ref> In the 1924 short film ''[[The Fugitive Futurist]]'' a gambler is offered to buy a future-viewing device which he intends to use to find out which horses to bet on, though the device turns out to be fake.<ref name="SFETimeViewer" /><ref>{{Cite encyclopedia |year=2022 |title=Fugitive Futurist, The |encyclopedia=[[The Encyclopedia of Science Fiction]] |url=https://sf-encyclopedia.com/entry/fugitive_futurist_the |access-date=2022-07-27 |last=Pearce |first=Steven |author1-link=<!-- No article at present (July 2022); retired civil servant --> |editor-last=Clute |editor-first=John |editor-link=John Clute |edition=4th |editor2-link=David Langford |editor3-link=Graham Sleight |editor3-first=Graham |editor3-last=Sleight |editor2-first=David |editor2-last=Langford}}</ref> The chronoscope in the 1936 short story "[[Elimination (short story)|Elimination]]" by [[John W. Campbell]] can show both the past and all possible futures.<ref name="Nahin2001" />{{Rp|pages=60}}
Future-viewing devices are occasionally limited in what they are able to show rather than being general-purpose.<ref name="SFETimeViewer" /> One example is the device in the 1939 short story "[[Life-Line]]" by [[Robert A. Heinlein]] which can determine an individual's moment of death by measuring the reflection from the future end of that person's [[world line]]; a similar device that reveals the manner but not time of death appears in the 2010 anthology ''[[Machine of Death]]: A Collection of Stories About People Who Know How They Will Die'' by [[Ryan North]], [[Matthew Bennardo]], and [[David Malki]].<ref name="SFETimeViewer" /><ref name="WebbTimeViewers" />{{Rp|pages=128}} Another is the instantaneous "[[Paul Dirac|Dirac]] communicator" introduced in the 1954 short story "[[Beep (short story)|Beep]]" by [[James Blish]] which due to the [[Faster-than-light communication|lack of a speed-of-light delay]] can send messages to the past.<ref name="SFETimeViewer" /><ref name="Nahin2011">{{Cite book |last=Nahin |first=Paul J. |url= |title=Time Travel: A Writer's Guide to the Real Science of Plausible Time Travel |date=2011 |publisher=JHU Press |isbn=978-1-4214-0120-1 |pages=148–150 |language=en |chapter=Faster-Than-Light Into the Past |author-link=Paul J. Nahin |chapter-url=https://books.google.com/books?id=wrQXMgOIcqUC&pg=PA148}}</ref>{{Rp|pages=148–150}}<ref>{{Cite encyclopedia |year=2011 |title=Dirac Communicator |encyclopedia=[[The Encyclopedia of Science Fiction]] |url=https://sf-encyclopedia.com/entry/dirac_communicator |access-date=2022-07-26 |author-link=Peter Nicholls (writer) |editor-last=Clute |editor-first=John |editor-link=John Clute |edition=4th |author2-last=Langford |author2-first=David |author1-last=Nicholls |editor3-link=Graham Sleight |editor3-first=Graham |editor3-last=Sleight |editor2-first=David |author1-first=Peter |author2-link=David Langford |editor2-last=Langford |editor2-link=David Langford}}</ref>
== See also ==
* [[Crystal ball]]
== References == {{Reflist}}
{{Science fiction}} [[Category:Fiction about time travel]] [[Category:Fictional technology]]