Scientists working with the Dark Energy Spectroscopic Instrument (DESI) have created the largest 3D map of the universe to date, allowing them to measure the expansion history of the universe over time. By analyzing patterns in the distribution of galaxies and quasars, scientists can determine the history of the universe’s expansion over time. The DESI collaboration analyzed the project’s first year of data, mapping out the locations of 6.4 million galaxies and quasars.
Measuring the Universe’s Expansion
This extensive map enables scientists to estimate the rate of expansion of the universe, thanks to a built-in size reference provided by sound waves in the early universe, known as baryon acoustic oscillations (BAOs). The BAOs act as a kind of “standard ruler” that allows scientists to measure the large-scale structure of the universe and track how it has changed over time.