As one might expect from a physicist who also writes SF, a collection by him will be a mix of fiction and fact/speculation. (Fiction) stories appear in quotes, (alternating) articles are italicized.

(Introduction by Robert L. Forward)
Antimatter
"Turn Left at the Moon"
Beanstalks
"Race to the Pole"
Starships
"Fading Into Blackness"
Antigravity
"The Singing Diamond"
Black Holes
"Acceleration Constant"
Space Warps and Time Machines
"Twin Paradox"
Future Speculations
"A Matter Most Strange"
Faster-Than-Light
"Self-Limiting"
(About the Author; Index)

Sources for the fiction are Analog (4), Omni, The Microverse - from 1983 to 1992. Many of the articles are revised or abridged from earlier versions in a 1988 collection of just articles: Future Magic. "Race to the Pole" and the last 3 articles appear to be original to this 1995 paperback. Some of these concepts were first explored in “Far Out Physics” - Analog August 1975.