Paul M. Sutter is an astrophysicist at The Ohio State University, host of Ask a Spaceman and "Space Radio," and author of "Your Place in the Universe." Sutter contributed this article to Space.com's ...

Einstein desperately wanted a unified theory of physics. Thanks to gravitational waves—the poster child of general relativity—his wish might just come true. Gravitational waves are ripples in the ...

Estimates are derived on the time and space derivatives of a shallow fluid flow in a channel of approximately rectangular cross section. These estimates depend upon the velocity and pressure being ...