This must be Italo Calvino's Cosmicomics. I do not have the book, but the Wikipedia article is clear:

• The story about the time before the Big Bang is "All at one point".
• The story about playing with subatomic particles may be "Games without end".
• "The Aquatic Uncle" is about moving the land and an uncle who stays in the ocean.

This must be Italo Calvino's Cosmicomics. I do not have the book at hand, but the Wikipedia article is clear:

• The story about the time before the Big Bang is "All at one point".
• The story about playing with subatomic particles may be "Games without end".
• "The Aquatic Uncle" is about moving to the land and an uncle who stays in the ocean.