Dark Energy Strengthened

Using a camera installed on the Hubble Space Telescope during the final servicing mission in 2009, scientists have measured the rate of expansion of the universe to a higher degree of accuracy than ever before. That measurement not only confirmed the universe is expanding, but found the rate of expansion is faster than previously thought.

The study used Type 1a supernovae as markers. That subset of supernovae explosions always reaches the same brightness level. Therefore, the distance to one of these stars can be determined by comparing the apparent magnitude-- how dim the star looks-- with how bright we know them to be.

The study strengthens the case for dark energy. Simply, gravity pulls mass towards mass, while dark energy rips mass apart. This is still a theoreical force; dark energy has not yet been confirmed in Nature. However, the expanding universe seems to be a fact, and evidence seems to suggest the rate of expansion is accelerating. Something must be behind that acceleration, and, for now at least, physicists are calling that something dark energy.