To overcome this challenge, Slosar uses a new technique that many were skeptical would even work: Instead of plotting light visible to humans, he and his collaborators look at the shadows Anže Slosar
Brookhaven National Laboratorythat massive gas clouds create when they obstruct light from the faraway quasars. For the first several months, the data looked too messy to map, and Slosar stewed in constant panic that he would fail. It took a few rounds of mathematical tweaks to coax out an actual signal. But once he did, data on 14,000 quasars from the BOSS telescope in New Mexico enabled Slosar to produce the largest-ever map of the ancient universe's structure—between 10 and 12 billion light years away—which in turn gives scientists insight into what the universe looked like very soon after it began.