A 3D map of the universe and a handle on dark energy

Astronomers at the Sloan Digital Sky Survey have achieved an amazing feat of mapping the galaxies in the universe in a three-dimensional plot. Not just that, knowing the expansion rate better also gives a better handle on the so-called dark energy. It was this interplay between the attractive effects of matter and dark matter on the one hand and the tearing apart effect of dark energy on the other hand that resulted in the speeding up of the universe’s expansion rate. The study made observations on the so-called Baryon Acoustic Oscillations — sound waves generated in the early universe from the big bang which happened about 13.8 billion years ago. What the astronomers at SDSS have done now is to calculate the way this acoustic scale has increased since then, thereby getting a handle on the expansion rate of the universe and thereby an estimate of dark energy, based on popular theories.