At the 223rd meeting of the American Astronomical Society in Washington, DC, astronomers announced that the distance between galaxies in the universe has been measured with 1% accuracy. The feat was achieved by the BOSS (Baryon Oscillation Spectroscopic Survey) team with the Sloan Foundation Telescope in New Mexico. The principal investigator of BOSS, Professor David Schlegel of the Lawrence Berkeley National Laboratory, had the following to say:
I now know the size of the universe better than I know the size of my house.
Twenty years ago astronomers were arguing about estimates that differed by up to 50%. Five years ago, we’d refined that uncertainty to 5%; a year ago it was 2%.
Baryon acoustic oscillations (BAOs) were used as a metric to measure distances between galaxies; BAOs are the remnants of pressure waves that moved through the universe in its early stages. The behavior of BAOs in the early universe shaped the layout of galaxies that we have today. The BOSS team used these waves to precisely measure large distances from far away, allowing the team to calculate vast intergalactic distances to within 1% accuracy.
The distances from this study will provide a standard in astronomy for years to come, which will allow astronomers to determine the nature of fundamental cosmic forces. The data have already indicated that dark energy is a cosmological constant – a force whose strength is not affected by variances in space or time.
The data also indicate that the universe is extremely flat, which has implications for whether or not the universe is infinite:
While we can’t say with certainty, it’s likely the universe extends forever in space and will go on forever in time. Our results are consistent with an infinite universe.
When the survey is completed (estimated for June), it will have collected high-quality spectra of 1.3 million galaxies and 160,000 quasars.
One percent accuracy will be the standard for a long time to come.