Added 2/26/04 Comments in italics and red by Rydin
Measurements Support 'Dark Energy' Theory
"Discovered only six years ago, dark energy may make up 70 percent of the universe. It holds the key to the future of the universe, depending on how strong and how permanent it is. Being Earthbound, the only way cosmologists can try to learn about it is through indirect observations. They use Hubble to look at the oldest, most distant supernovae they can find, and measure the light coming from them. This light would have left the exploding stars billions of years ago and its color, known as red shift, tells astronomers about how fast they were accelerating at the time. This gives clues about the expansion of the universe and its age."
"The latest results come from the measurements of multiple Type Ia supernovas that exploded when the universe was half its present age of nearly 14 billion years. The apparent brightness of a certain type of supernova allows scientists to gauge the expansion rate of the universe at different times in the past. This new discovery is already widely accepted because it explains many observations. Supporting evidence comes from studies of global geometry, structure formation, cosmic age, and galaxy clustering. They leave little doubt that in some sense Einstein's "cosmological constant" is a reality. He theorized its existence to balance the universe against normal gravity and keep it from collapsing on itself. Einstein ultimately dismissed the theory as his greatest blunder. The energy of the Universe is dominated by empty space whose gravitational effect is to pull the Universe apart. Since we have no theory of dark energy, anything we learn is an unexpected discovery. For this very reason, dark energy is the most exciting new development in fundamental physics."
Hence, a recent indirect measurement of an apparent acceleration of the expansion of the universe - no matter that we have difficulties measuring even velocity and distance - has been interpreted as supporting a concept that Einstein called his greatest blunder. Even though there is no theory of dark energy, it is already widely accepted!