is a short story
A short story is a work of fiction that is usually written in prose, often in narrative format. This format tends to be more pointed than longer works of fiction, such as novellas and novels. Short story definitions based on length differ somewhat, even among professional writers, in part because...
by Arthur C. Clarke
Sir Arthur Charles Clarke, CBE, FRAS was a British science fiction author, inventor, and futurist, famous for his short stories and novels, among them 2001: A Space Odyssey, and as a host and commentator in the British television series Mysterious World. For many years, Robert A. Heinlein,...
, which was expanded and modified into the novel and movie 2001: A Space Odyssey
. Clarke expressed impatience with the common description of it as "the story on which 2001
is based." He was quoted as saying, it is like comparing "an acorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...
to the resulting oak-tree
Oak Tree may refer to:*Oak, the tree*Oak Tree, County Durham, a village in County Durham, England*The Oaktree Foundation, a youth-run aid and development agency*Oak Tree National, golf club in Edmond, Oklahoma...
"The Sentinel" was written in 1948 for a BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
competition (in which it failed to place) and was first published in the magazine 10 Story Fantasy
in 1951, under the title "Sentinel of Eternity
". It first appeared in the USA in The Avon Science Fiction and Fantasy Reader
published by Avon Periodicals, Inc. in 1951. It was subsequently published as part of a short story collection in Expedition to Earth
Expedition to Earth is a collection of science fiction short stories by Arthur C. Clarke.There are at least two variants of this book's table of contents - in different editions of the book . Both variants include the stories History Lesson and Encounter in the Dawn...
in 1953. It is also collected in The Nine Billion Names of God
The Nine Billion Names of God is a collection of science fiction short stories by Arthur C. Clarke.-Contents:This collection includes:* "The Nine Billion Names of God"* "I Remember Babylon"* "Trouble with Time"* "Rescue Party"* "The Curse"...
and The Lost Worlds of 2001
The Lost Worlds of 2001 by Arthur C. Clarke was published in 1972 by Signet as an accompaniment to the novel 2001: A Space Odyssey.The book itself consists in part of behind-the-scenes notes from Clarke concerning scriptwriting , as well as production issues...
. Despite the initial failure of the story, it changed the course of Clarke's career.
The Sentinel is a collection of science fiction short stories by Arthur C. Clarke originally published in 1983.The stories, written between 1946 and 1981 originally appeared in a number of magazines including Astounding, Famous Fantastic Mysteries, Thrilling Wonder Stories, Ten Story Fantasy,...
(published 1982) is also the title of a collection of Arthur C. Clarke short stories, including the eponymous "The Sentinel", "Guardian Angel" (the inspiration for his Childhood's End
Childhood's End is a 1953 science fiction novel by the British author Arthur C. Clarke. The story follows the peaceful alien invasion of Earth by the mysterious Overlords, whose arrival ends all war, helps form a world government, and turns the planet into a near-utopia...
), "The Songs of Distant Earth", and "Breaking Strain
"Breaking Strain," also known as "Thirty Seconds Thirty Days," is a short story by Arthur C. Clarke, first published in 1949. It was adapted into a movie in 1994 under the title .-Plot summary:...
The story deals with the discovery of an artifact on Earth's Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
left behind eons ago by ancient aliens. The object is made of a polished mineral and tetrahedral
In geometry, a tetrahedron is a polyhedron composed of four triangular faces, three of which meet at each vertex. A regular tetrahedron is one in which the four triangles are regular, or "equilateral", and is one of the Platonic solids...
in shape, and is surrounded by a spherical forcefield. The first-person narrator speculates at one point that the mysterious aliens who left this structure on the Moon may have used mechanisms belonging "to a technology that lies beyond our horizons, perhaps to the technology of para-physical forces."
The narrator speculates that for millions of years (evidenced by dust buildup around its forcefield) the artifact has been transmitting signals into deep space, but it ceases to transmit when, some time later, it is destroyed "with the savage might of atomic power". The narrator hypothesises that this "sentinel" was left on the moon as a "warning beacon" for possible intelligent and spacefaring species that might develop on Earth.
This quotation illustrates the idea, and its ramifications:
- It was only a matter of time before we found the pyramid and forced it open. Now its signals have ceased, and those whose duty it is will be turning their minds upon Earth. Perhaps they wish to help our infant civilization. But they must be very, very old, and the old are often insanely jealous of the young.
In 2001: A Space Odyssey
, the operation of the sentinel is reversed. It is the energy of the sun, falling for the first time on the uncovered artifact, that triggers the signal that creatures from the Earth had taken the first step into space.