Biggest X-ray laser in the world generates its first laser light

European XFEL, the biggest X-ray laser in the world, has generated its first X-ray laser light. The X-ray light has a wavelength of 0.8 nm — about 500 times shorter than that of visible light. At first lasing, the laser had a repetition rate of one pulse per second, which will later increase to 27,000 per second.

(via WSJ)