In 1998, two rival teams of astronomers expected to measure how gravity was slowing down the universe's expansion. Instead, they discovered something that defied everything we thought we knew—the universe is accelerating, driven by a mysterious force we call dark energy. Twenty-five years later, we still don't know what 70% of our universe actually is. Hosted by Simplecast, an AdsWizz company. See https://pcm.adswizz.com

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