A Science Fiction novella about a scientist who invents a time travel machine and travels about a hundred years into the future with his assistant but discovers that they can only travel forward in time. They decide to continue travelling forward in hopes that science discovered a way to travel backward in time so they could return home. They keep stopping at various times into the future meeting advanced humans, aliens, advanced societies and primitive ones... Originally appeared in Super Science Stories in Nov 1950. Collected in:

• "Past Times" by Poul Anderson (1984)
• "Alight In the Void" by Poul Anderson
• "The Last Man on Earth" edited by Isaac Asimov, Martin H Greenberg, and Charles G Waugh(published by Fawcett 1982)