The Cube Root of Uncertainty (1970) - a collection of stories by Robert Silverberg. About half of these make their first appearance in a Silverberg collection - in the 1970 Macmillan hardcover of this book.

(Introduction by Robert Silverberg)
Passengers
Double Dare
The Sixth Palace
Translation Error
The Shadow of Wings
Absolutely Inflexible
The Iron Chancellor
Mugwump Four
To the Dark Star
Neighbor
Halfway House
Sundance

These stories originally appeared from 1956 to 1969 - in Orbit 4, Galaxy (5), Astounding, IF (2), Fantastic Universe, The Farthest Reaches, and Magazine of F&SF.