This is a short story I read back in the '90s (but I think it's been written before that), in which someone develops a sort of "space/time warp tunnel" to travel to work from his home.
He uses the tunnel daily until he finds that there is a sort of "hole" in it. The hole is initially tiny but at some point he can look into it and he sees that there are flora/fauna developing, like some alternate world.
After another few days, human life forms start to appear on the other side of the hole and he thinks they can see him.
At some point he actually makes contact with these alternate-reality humans and they give him a book as a present and he understands that the book is about him, and the title is