Scientists have proposed new instruments that would use spectroscopy to decode dark matter, dark energy and cosmic inflation. Telescope images can tell us a whole lot about celestial objects: where they are located in the sky, how bright they are, how big they are and their shapes, among other attributes. But these pictures are two-dimensional, and astrophysicists need a different tool to measure how far away objects are from Earth in our ever-expanding universe.  That tool is spectroscopy.  “The spectroscopic information adds depth,” says Marcelle Soares-Santos, an assistant professor of physics at the University of Michigan who uses spectroscopy data in her work investigating the expansion of the universe. “It’s one of the key tools we have available to unveil mysteries about the physics of dark energy, dark matter and inflation because it allows us to build a 3D map.” Spectroscopy relies on the fact that all matter emits light, and different materials emit...