
Outer space: The answer to runnin' in the wind
Runners and cyclists can tolerate heat and cold but the thing they dislike most is wind. They know it produces slower times. Can we show them why?
Martin Gardner
When Einstein formulated his general theory of relativity he noticed something disturbing. According to his equations, gravity should cause the Universe to contract until it eventually collapses in on itself in a big crunch. This idea jarred with Einstein, so he introduced a repulsive component of gravity into his equations which exactly balanced the attractive one, giving an elegantly static Universe. The term became known as the cosmological constant.