cosmic acceleration

Cosmic acceleration refers to the observation that the universe is expanding at an increasing rate. Initially, astronomers thought gravity from matter would slow this expansion. However, studies of distant supernovae and the cosmic microwave background suggest that something else is at play—an unknown energy, often referred to as dark energy. This energy seems to push galaxies apart more forcefully over time, causing the expansion of the universe to speed up. Understanding cosmic acceleration is crucial for astrophysics, as it challenges our knowledge of fundamental forces and the overall fate of the universe.