Physicists weren't sure at first if this unusual approach would work, but over the last year, as the data was analyzed, it became clear that the measurements matched perfectly with theoretical predictions of where the BOA "peak" should be.
So the picture of our universe, a mere three billion years after the big bang, shows that dark energy worked much the same way it does today - a constant part of space throughout the cosmos that gradually became more dominant as matter in the universe moved further and further apart.
"It looks like the roller coaster crested the hill just about seven billion years ago, and we're still going," said Busca.
Images: Top: Artist's rendering of ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun. Credit: M. Kornmesser, European Southern Observatory. Center: An illustration of the concept of baryon acoustic oscillations, which are imprinted in the early universe. Credit: Chris Blake and Sam Moorfield. Bottom: Light from distant quasars gets absorbed by hydrogen gas, leaving behind a "forest" of absorption lines in the spectrum. Credit: Zosia Rostomian, LBNL; Nic Ross, BOSS/LBNL; Springel et al, Virgo Consortium and the Max Planck Institute for Astrophysics.