The video game No Man’s Sky presents its virtual space explorer with a universe that could contain more than 18 quintillion planets. (If you visited each one for a second it would take you 570 million years.)
These virtual worlds – their topography, geology, flora, fauna – are generated by mathematical formulas, which depend on a language called an L-system.
The system describes the sort of expansive growth shown by a tree.
It is named after the Hungarian biologist Aristid Lindenmayer, who used it from the late 1960s to describe the development of simple organisms such as yeast and fungi.
