Extrapolation
Extrapolation is a way for writers to take something that is known or common now and speculate what it might be like in the future. Using extrapolation, writers:
* build fictional models by extending aspects of present-day science and history into the future;
* use scientific laws and extensions from present technology to construct futuristic environments;
* forecast futre history by extending long-and short-term social trends;
* are usually consistent with contemporary science, economics, and psychology, making the forecasting plausible.