The Time Machine is a science fiction novel by H. G. Wells, published in 1895. Wells is generally credited with the popularisation of the concept of time travel by 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. This work is an early example of the Dying Earth subgenre. The portion of the novel that sees the Time Traveller in a distant future where the sun is huge and red also places The Time Machine within the realm of Eschatology; that is the study of the end times, the end of the world, and the ultimate destiny of mankind. The Time Machine has since been adapted into two feature films of the same name, as well as two television versions, and a large number of comic book adaptations. It has also indirectly inspired many more works of fiction in many media.