BRILLIANCE Four new books put Einstein’s general theory of relativity in historic and scientific context.
Ferdinand Schmutzer/Wikimedia Commons
GETTING A GRIP ON GRAVITY Einstein's general theory of relativity explains gravity as a distortion of space (or more precisely, spacetime) caused by the presence of matter or energy. A massive object generates a gravitational field by warping the geometry of the surrounding spacetime.
Nicolle Rager Fuller
EARLY BIRD Engineers work on Intelsat I, also known as Early Bird, one of the first international communication satellites. It launched in 1965 to relay and broadcast TV signals between Europe and the United States.