Near the end of the millennium, new observations and analyses are suggesting answers to some of the most profound and ageless questions. What is the extent of the Universe? How old is it? What is its shape? What is its ultimate fate? The answers to these questions have come from philosophers and religious leaders, but in the realm of experimental science answers are now coming from exploding stars and the gentle tug of gravity. Recent astronomical observations suggest that the Universe may be influenced by a positive 'cosmological constant' that affects its evolution. On page 252 of this issue, Zehavi and Dekel present a synthesis of several observations that tightens the case for a positive cosmological constant. The likely implications for the Universe of a positive cosmological constant are eternal, accelerating expansion.
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