Universal Expansion Rate Calculated with Extreme Precision

Astronomers operating the NASA Hubble Space Telescope announce that they were recently able to calculate the expansion rate of the Universe with great precision. In the process, the group was able to rule out an alternate theory on the nature of dark energy.

This is the force that astrophysicists believe is responsible for the ever-accelerating rate at which our Universe expands. The measurable, observable reality is not enough to explain why galaxies are flying away from each as if pushed.

Dark energy – as a concept – was developed by experts in order to explain what they were observing in space. The same thing goes for dark matter, only it was proposed to explain why galaxies have so much mass without having the stars to provide it.

When it comes to explaining the theoretical origin of dark energy, there are several theories that experts proposed for consideration. One of them shows that the galactic motion we are perceiving is in fact an illusion of some sort.

The idea states that we are living inside a bubble in space. This structure is some 8 billion light-years across, and our galactic neighborhood is located in its center. If that were true, the thinking goes, then the way we see galaxies – as flying away from each other – would be an illusion.

But this theory was dismissed following the new observations. The team that carried out the study was led by Space Telescope Science Institute (STScI) and Johns Hopkins University (JHU) expert Adam Riess, Universe Today reports.

The SHOES (Supernova H0 for the Equation of State) team was in charge of processing the data Hubble sent back. The main job this group has is to refine Hubble's Constant, the number that shows the expansion rate of the Universe.

Its uncertainty level was until now very high, but the new calculations have reduced it to only 3.3 percent. The research team published details of its accomplishment in the April 1 issue of the esteemed Astrophysical Journal.

“We are using the new camera on Hubble like a policeman’s radar gun to catch the universe speeding. It looks more like it’s dark energy that’s pressing the gas pedal,” Riess concludes.

“WFC3 is the best camera ever flown on Hubble for making these measurements, improving the precision of prior measurements in a small fraction of the time it previously took,” adds SHOES collaborator and Texas A&M in College Station expert Lucas Macri.