"Transience" is a short story by Arthur C. Clarke.
Probably the most interesting aspect of this story is its opening part - reluctant exploration of the surrounding world by a little child in a way that reminds of the first story in 2001: A Space Odyssey.
The story is told through the medium of three children playing at about the same physical location on Earth, but across vast gulfs of time.
It is collected in The Other Side of the Sky.