The Singers of Time by Frederik Pohl & Jack Williamson, Hardcover

Brand new condition with near perfect dust jacket. Non-smoking home.

Synopsis:

When the conquering aliens on Earth find out that their home planet has been destroyed, they turn to the humans--whom they have long treated as intellectually inferior--for the scientific help they need to rescue their planet

From Library Journal:

A race of turtle-like creatures conquers Earth, imposing a gentler set of values on humankind, outlawing destructive technology, and denying the validity of human scientific theories. When their home planet disappears into a black hole, however, the aliens' only hope for the future hinges on the possibility that humanity's flawed sciences might contain a glimmer of truth. Two veteran sf authors combine their strengths to produce a novel that both explains and explores the "mysteries" of modern science. For most sf collections.