The
2001 screenplay was written by Clarke and Kubrick jointly, based on the seed idea in "The Sentinel" that an alien civilization left an object on the Moon to alert them to humankind's attainment of space travel. In addition, the 1953 short story "Encounter in the Dawn" contains elements of the first section of the film, in which the ancestors of humans are apparently given an
evolutionary nudge by extraterrestrials. The opening part of another Clarke story, "
Transience", has plot elements set in about the same time in human history, but is otherwise unrelated. The 1972 book
The Lost Worlds of 2001 contains material that did not make it into the book or film. Clarke's first attempt to write the sequel to
2001 was a film screenplay, though he ultimately wrote a novel instead that was published in 1982. Clarke was not directly involved in the production of the second film, although he did communicate with writer/director Peter Hyams a great deal during the production via the then-pioneering medium of
e-mail (as published in the book
The Odyssey File) and also made a non-speaking
cameo appearance in the film. Kubrick had no involvement in the
2010 novel or film, or any of the later projects. The
Space Odyssey series combines several science-fiction narrative conventions with a
metaphysical tone. Since the stories and settings in the books and films all diverge, Clarke suggested that the continuity of the series represents happenings in a set of
parallel universes. One notable example is that in the
2001 novel, the voyage was to the planet Saturn. During production of the film, it was decided that the special effects for Saturn's rings would be too expensive, so the voyage in the film is to Jupiter instead. The second book,
2010,
retcons the storyline of the first book to make the destination Jupiter as seen in the film. Clarke stated that the
Time Odyssey novels are an "orthoquel" – a
neologism coined by Clarke for this purpose, combining the word
sequel with
ortho-, the Greek prefix meaning "straight" or "perpendicular", and alluding to the fact that time is
orthogonal to space in
relativity theory – to the
Space Odyssey series. == Main characters==