<HTML>Well Adam, up untill recently there were two main models of the Universe,
one which expands than slows down and finaly starts contracting again and the second where Universe just keeps expanding. Einstein's first equation actualy predicted the expanding model but when he was told that astronomers of that time thought that the Universe is static he added a factor which made his equation compliant with than current model. When , years later, the fact that Universe is expanding was discovered Einstein called his redevised equation "his worst misake ever".
If the expand-contract model was the better one than the "escape speed" of the galaxies should be diminishing steadily but the latest observations show that it is actually ever increasing. So ,at least for now, the ever expanding model better explains the observable data.
Regards D.P.</HTML>
