Dark energy: What Hubble says it ain't

William Atkins
Tuesday, 15 March 2011 22:45

Science - Space

The NASA Hubble Space Telescope, still performing at peak efficiency, has just performed a bit of dark magic. Astronomers now can rule out certain theories that deviate too far from more accurate measurements of the universe's expansion rate.

According to the NASA media release NASA's Hubble Rules Out One Alternative To Dark Energy, 'Adam Riess of the Space Telescope Science Institute (STScI) and Johns Hopkins University in Baltimore, Md., led the research.'

Dr. Adam G. Riess, a professor of physics and astronomy at Johns Hopkins University, led a team called Supernova Ho for the Equation of State (SHOES). The team worked with the Hubble Space Telescope to determine the Hubble constant to a much more precise value and, consequently, to allow for a much better determination of the behavior of dark energy.

Dark energy is a hypothetical type of energy that astronomers conjecture may evade all of space. Its presence, astronomers hypothesize, may help to increase the rate of expansion of the universe.

Astronomers think dark energy is a valid form of energy because something has to explain the increase in the rate of expansion of the universe that we see today through our telescopes and other astronomical measuring devices.

And, astronomers think there is a lot of dark energy out there - approximately 73% of all the mass energy in the universe.

Astronomers used the Hubble Space Telescope (HST) to help determine the Hubble constant to an even more precise value (that is, there is less uncertainty about its value), which determines just how fast or slow the universe is expanding.

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