Jonbar hinge


In science-fiction criticism, a Jonbar hinge or Jonbar point is the fictional concept of a crucial point of divergence between two outcomes, especially in time-travel stories. It is sometimes referred to as a Jon Bar hinge or change-point.

Origin

The phrase is derived from the Jack Williamson novel The Legion of Time. It refers to one action from its character John Barr, in which picking up one of two objects is a major turning point in history: choosing one will lead to a utopian civilization named Jonbar, while the other to the tyranny of the state of Gyronchi.
This crucial moment, is thus a "Jonbar point" in the novel's timeline, a forking-place upon which hinges the rest of its history.

Background

Jonbar hinges often refer to small nondescript events that had an important effect on history, but because of time travel the outcome of the choice or event was changed leading to a different future or an alternate history. It can, however, refer to any kind of change in history without having to deal with time travel, as Paul Di Filippo used the term when reviewing S. M. Stirling's In the Courts of the Crimson Kings. In Michael Chabon's The Yiddish Policemen's Union the jonbar hinge was the death of the main opponent to the King-Havenner Bill, which, if passed, would have allowed Jewish refugees to settle in Alaska. The jonbar hinge in Bring the Jubilee, Ward Moore's 1953 novel of American Civil War alternate history, is Robert E. Lee's victory at the 1863 Battle of Gettysburg.
The term is also used when describing an important upcoming event or decision humanity will have to make in the future.