Space & Astronomy

Mystery surrounds universe's rate of expansion

By T.K. Randall
August 5, 2018

Image Credit: (PD) NASA/ESA/ESO/Wolfram Freudling et al via Wikimedia Commons The mystery concerns the fact that new measurements from the Hubble Space Telescope and the Gaia space telescope indicate that the rate of expansion nearby is 73.5 kilometers per second per megaparsec - a figure that contradicts earlier measurements of the rate of expansion in the distant universe which appears to be only 67 kilometers per second per megaparsec.

Even stranger is the fact that these two figures seem to be getting further apart, rather than closer together, the more scientists refine their calculations.

"At this point, clearly it's not simply some gross error in any one measurement," said study lead author Adam Riess of the Space Telescope Science Institute (STScI) in Baltimore.

"It's as though you predicted how tall a child would become from a growth chart, and then found the adult he or she became greatly exceeded the prediction. We are very perplexed."The mystery adds to the already substantial list of questions scientists have about the expansion of the universe. Why is it expanding ? Why is the expansion accelerating ? What is it expanding in to ?

Some believe that the key lies in dark matter and dark energy - two invisible yet highly influential forms of matter and energy that we cannot directly detect.

Others, meanwhile, suggest that a type of undiscovered subatomic particle may be to blame.

The search for answers continues.

Source: Space.com

Tags: Universe, Expansion