Brief  Biography:

"Larry Niven's love of science drove him to write stories on the cutting edge of scientific discovery throughout his career. Neutron stars were a newly-described phenomenon when Niven first wrote about them in 1966, and the modern-day theories of "dark matter" inspired him to write "The Missing Mass" in 2000 . . . In between, he wrote stories about quantum black holes (following a talk with Steven Hawking), solar flares, and the "real" reason Saturn's rings appeared twisted in Voyager I's imagery." ^[1] 

For a more complete biography of the author, Larry Niven, please go to the Known Space website.

"The Theory and Practice of Time Travel" is a non-fiction essay that appears in a collection of his short stories, All the Myriad Ways. These stories deal in part with time travel and parallel universes.^[2]

This essay presents an argument looking at the implications of time travel, particularly at the grandfather paradox:

"NIVEN'S LAW: IF THE UNIVERSE OF DISCOURSE PERMITS THE POSSIBILITY OF TIME TRAVEL AND OF CHANGING THE PAST, THEN NO TIME MACHINE WILL BE INVENTED IN THAT UNIVERSE."^[3]

Thus all possible time paradoxes are evaded.

When reading this essay, one will recognize that Niven is conversing with two audiences. One, those interested in time travel and its narratives, and the second, the other writers of science fiction time travel tales. He challenges their conceptions of time travel:

"If time travel is so manifestly impossible, why does every good and bad science fiction writer want to write a new, fresh time travel story?"^[4]

It is a question one may well ask themselves in the course of this class.

Overview:

Niven begins his essay with some background, the origin of time travel rooted in fantasy as opposed to science fiction.^[5]He delves into time machines and an introduction of the grandfather paradox. From there, he enumerates in great detail how time travel into the past "violates certain of what we regard as laws of nature."^[6] The four defenses of time travel used by other authors and theorists is followed by his objections to each.^[7]