I know this has been a huge thing in Hollywood in the past few years but I have seen writers write fiction books about it. I saw the last popular post about time travel and it also made me think of alternative realities as well… I would love to do some research or read some publications on some physicists to see if it kinda is possible. But anyway, what are your favorite alternative reality books, or what books have made you question the possibility?
Stephen Baxter is a great author for this. He’s written lots and lots of books with premises like this. One, Raft, is set in an alternate universe where Newton’s Constant is much higher than in our reality–so much that gravity is the dominant forces in chemical reactions, and even humans have significant gravity fields. Another, Manifold: Time, has its protagonist wander through a succession of universes with different physical laws, all hostile to life–until he finds that physics itself is subject to evolution, and that the complex universe in which we find ourselves is very conducive to spawning daughter-universes. A third book, Manifold: Origin, has a dimension-jumping moon leap between different universes with different versions of Earth, shuffling human and human-related populations between them (it’s suggested that it was created by humanity’s distant descendants to give us an appreciation for human diversity; not sure how well that works, since the smartest hominids kidnapped end up creating slave-driving societies, abusing their distant cousins).
On a more human scale, Voyage is a book he wrote where JFK survives his assassination and the US goes to Mars in the 1980s. Extremely technically well-researched.
You can get a taste of his writing style in this short-story, which also deals with universe-jumping:
http://www.infinityplus.co.uk/stories/moon6.htm