Black holes. Curved space-time. Light bent by gravity. Albert Einstein's general theory of relativity has some pretty bizarre implications. In 1918, Austrian physicists Joseph Lense and Hans Thirring calculated that the theory has even more of a twist: Like an eggbeater, a spinning object twirls the very fabric of space-time around it.
Astronomers may finally have found evidence for this strange effect, known as frame dragging or the Lense-Thirring precession. Reporting in the Sept. 1 Astrophysical Journal Letters, the researchers base their findings on the study of rapid variations in the brightness of X rays emitted by neutron stars, superdense remnants of exploded stars. Neutron stars cram more matter than the sun into a sphere only 20 kilometers in diameter.