NED - California Institute of Technology quotes

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One of the most puzzling properties of our universe is that it is now expanding at a rate very close to the critical divide separating the ever-expanding universes from the recollapsing ones. It is a puzzle because as the universe expands it tends to deviate steadily from the critical divide because of the attractive force of gravity. In order that we be as close to the divide as is observed today, the universe must have begun expanding extraordinarily close to the divide originally.

John Barrow (1991)