Here is what the page “The Universe Is Racing Apart. We May Finally Know Why.” contains. Get a special 35% discount on an annual digital subscription to The Economist at We've known that the universe is expanding since 1929, and that its expansion is accelerating since 1998. The culprit behind the acceleration is unknown, so we live with a stand-in term "dark energy".
Our modern cosmological model assumes that dark energy has a constant density--always the same amount of the outward-shoving stuff per volume. But there's recent evidence to the contrary- The full version stays on the original page, which this listing opens directly.