Today, May 11th, marks the hundred and first anniversary of the announcement of Albert Einstein's General Theory of Relativity. This supplemented his earlier work on "special relativity", which stated that electromagnetic energy, or light, travels at the same speed, whether you are moving toward the source of the light, or away from it. In 1916, with general relativity, Einstein suggested that space and time are interwoven, and that space itself is curved, the amount of curvature depending on the gravity fields of massive objects like stars and galaxies. Planets don't follow orbits because the sun is pulling on them; rather, they revolve because the sun's mass makes a big dent in the fabric of space-time, and the planets travel like marbles rolling on the inside of a funnel. Our sun’s gravity field is so great that the light of stars themselves are displaced if they venture too near it. It's all pretty deep.