Shrinking spectrometersDual-comb spectroscopy is a powerful technique that uses the interference of two closely related combs to map spectroscopic features directly into a frequency domain that can be read by electronics. Suhet al.developed a dual-comb spectroscopy approach using combs produced by silica microresonators fabricated on a silicon chip. Perhaps high-resolution spectroscopy will soon be shrunk to the chip scale, doing away with the need for bulky spectrometers.Science, this issue p.600