The 'Divided Man' short SF story may use the concept of division to comment on society. For instance, the divided man could represent the fragmented nature of modern humans. We are often divided between our work self, our family self, and our individual self. The story could be a metaphor for how we struggle to keep these different parts of ourselves in harmony, and what happens when we fail to do so.
One possible ending could be that the divided man finds a way to merge his divided parts back together and becomes a whole person again, achieving inner peace and a new sense of self.
Yes, it was quite popular. Science fiction often explored the human condition through the lens of extraordinary scenarios. Stories about men in sf settings could range from space exploration to encounters with alien species, which fascinated many readers.
A free sf (science fiction) invariant short story could be a science fiction story that has some element which remains constant or 'invariant' throughout the narrative, and it's available for free. It might be a story where a certain scientific principle or a character trait stays the same despite the various events that occur.
One important characteristic is their ability to make readers think. Even in a short span, they can pose big questions about humanity, technology, and the universe. For instance, a short sf story might make you wonder about the ethics of cloning or the implications of finding intelligent alien life. The brevity also forces the writer to use language efficiently, making every word count to build the story's world and characters.
Yes. In a'man sf story', it's highly likely to have male protagonists as the name kind of implies. Men were often the focus in early sf works, exploring new worlds, facing alien threats, etc.