The Economic Times

In 1917, Einstein called it his 'greatest blunder', but the idea he discarded returned decades later to become central to modern cosmology

Einsteins cosmological constant was initially introduced to create a static universe but was later abandoned. Astronomers subsequently discovered that the universe was expanding, contradicting Einsteins original static model. Decades later, observations revealed that this expansion was actually accelerating. The acceleration is now attributed to dark energy, with the cosmological constant providing one explanation for its nature.