Field
Cosmology, astrophysics, and the Earth system — the expansion of the universe, its origins, and our changing planet.
By measuring distant exploding stars, this team found that the expansion of the universe is speeding up, not slowing down. The acceleration implies a mysterious 'dark energy' filling space — one of the great puzzles of modern physics.
The Alvarez team proposed that a giant asteroid impact caused the mass extinction that killed the dinosaurs. Their evidence was a worldwide layer of iridium — an element rare on Earth but common in asteroids — at the geological boundary.
Penzias and Wilson reported a faint, uniform microwave hiss coming from every direction in the sky that they could not eliminate. It was the cosmic microwave background — the leftover radiation from the hot early universe, and decisive evidence for the Big Bang.
Keeling reported the first precise, systematic measurements of atmospheric carbon dioxide, taken at Mauna Loa and the South Pole. The data revealed a regular seasonal cycle and the beginnings of the steady rise now known as the Keeling Curve.
Hubble showed that distant galaxies are receding from us at speeds proportional to their distance — the first observational evidence that the universe is expanding. The proportionality is now called Hubble's law.