"With the cosmological term, Einstein had given other researchers an intriguing new variable to play with and manipulate in an attempt to fit their s with the new ideas they were considering and with the observations that were starting to be made. It also opened the door for theorists to experiment with the equations — with or without the newly introduced term — to see what other interpretations might be plausible, other than a universe that neither expands nor contracts. One could, of course, conjure up all kinds of conceivable universes with wildly different properties. However, among the conceivable universes, only those that satisfied general relativity’s could be deemed plausible. And among the possible universes sifted out through mathematics, perhaps one of those might bear a close resemblance to the universe we actually inhabit."