How do you create the largest 3-D map of the universe? It’s as easy as teaching 5,000 robots how to “dance.” DESI, the Dark Energy Spectroscopic Instrument, is an experiment that will target millions of distant galaxies by automatically swiveling fiber-optic positioners (the robots) to point at them and gather their light. In creating this detailed map, scientists hope to learn more about dark energy, which is driving the accelerating expansion of the universe.