The Time Machine is a science fiction novella by H. G. Wells.This 32,000 word story is generally credited with the popularisation of the concept of time travel using a vehicle that allows an operator to travel purposefully and selectively. The term "time machine", coined by Wells, is now universally used to refer to such a vehicle. Wells also introduced the idea of time being the "fourth dimension", as well as an early example of the Dying Earth subgenre.