世界上最完整的三维宇宙图

EarthSky

David Schlegel: We have these big unknowns about just the overall construction of the universe. And I hope we get some answers.

You are listening to astrophysicist David Schlegel. He is the principal investigator of the Baryon Oscillation Spectroscopic Survey – or BOSS – project. Over the next five years, BOSS will map over a million galaxies to reveal what Schlegel called the “large scale structure” of the universe.

David Schlegel: We see structures on very, very large scales. And there are features in these structures. And some of those features date back to the very early universe. And in particular, one of those features is the propagation of sound waves from when the universe was very young.

Schlegel said that just moments after the cosmic Big Bang 13.7 billion years ago, all light and matter in the universe were coupled together as one hot, soupy plasma.

David Schlegel: It was just this plasma of protons and electrons and photons. And sound waves could propagate in that medium at something close to the speed of light.

Schlegel said that the universe’s first sound waves imprinted themselves into everything and shaped the distribution of galaxies. The BOSS project will map millions of galaxies using a ruler on the scale of 500 million light years.