Gravity Probe B
…not to turn this into a science blog, but a significant event in basic physics research occurred today with the launch by NASA of Gravity Probe B.
The “B” was built to confirm the effect known as Frame-dragging - as predicted by Einstein’s theory of general relativity. It employs 4 of the world’s most perfect spheres in a gyroscope. 
“B” will measure both the geodetic effect (bending of spacetime), and frame-dragging (twisting of spacetime). Frame-dragging predicts that rotating bodies drag space and time around themselves as they rotate, in a kind of vortex or whirlpool.