Six Word Stories

The butterfly effect is a part of chaos theory that “small variations of the initial condition of a dynamical system may produce large variations in the long term behavior of the system.” Basically, if time travelers change the past by as little as killing a single butterfly, its compound effect can completely change the future of the world.

(In general relativity, an event horizon is a boundary in spacetime, most often an area surrounding a black hole, beyond which events cannot affect an outside observer. Light emitted from beyond the horizon can never reach the observer, and anything that passes through the horizon from the observer’s side appears to freeze in place.)