Editing Dark Energy (section)

=== Discovery and Observations ===
The concept of Dark Energy was first proposed in the late 1990s when two independent teams of astronomers, the Supernova Cosmology Project and the High-Z Supernova Search Team, discovered that distant Type Ia supernovae were dimmer than expected. This observation suggested that the universe’s expansion was not slowing down due to gravity as previously believed, but was instead accelerating. This acceleration implied the existence of a previously unknown force or energy that counteracted the pull of gravity.

Further studies using the cosmic microwave background radiation, large-scale galaxy surveys, and gravitational lensing have provided additional evidence for Dark Energy, though its exact nature remains one of the biggest mysteries in cosmology.