Inventors

Early sf began with individual discoverers or inventors. The list grows and extends into later sf:

Frankenstein
the Time traveler
Cavor
Griffin, the Invisible Man
Verne's Nemo and Robur
Heinlein's Pinero and solar energy pioneers
CS Lewis' Weston and Filostrato
Blish's Haertel etc
Asimov's Seldon
Anderson's Valti

A twentieth century inventor builds the time projector in "Flight to Forever" but time machines arrive from future civilizations in Time Patrol and other works. Much sf is set in periods when the discoveries have been made and technology permeates society. Future histories do not have to start with the first spaceship.