New data raise prospect of ‘Big Rip’ destroying cosmos
New measurements of light from distant exploding stars were supposed to illuminate the dark energy that is pushing the cosmos apart. Instead they have further shrouded the universe’s fate.
Dark energy first made headlines in 1998, when researchers found that light from faraway supernovas was dimmer than expected, suggesting that the universe is expanding at a faster and faster pace. To explain this acceleration, scientists surmised the existence of dark energy, which pushes space outward (SN: 4/7/01, p. 218). Most physicists suspect that dark energy is a form of vacuum energy known as the “cosmological constant” because its strength never varies. If so, a number called w,