What to read this week: Emma Chapman’s mind-expanding Radio Universe
ALMA, the Atacama Large Millimeter/submillimeter Array, Chile ESO/C. Malin Radio UniverseEmma ChapmanJohn Murray When he was 16 years old, Albert Einstein imagined chasing after a beam of light and, as the story goes, this feat of imagination helped him develop the now-famous theory of special relativity. Physicist Emma Chapman also chases a light signal through the known universe and up to its very edges in her new book, Radio Universe: How to explore space without leaving Earth (in the US, its title is The Echoing Universe and it is out on 19 May). But while Einstein wanted to hop onto the light beam and experience the cosmos’s fastest speed, the light Chapman is after plays the role not of a carrier, but of an explorer, guide and messenger. “The universe already speaks the language of light,” she writes, and her book offers a wonderful insight into how humans have used radio telescopes to learn and become fluent in that language, too. As a wave of electromagnetism, light can have many different wavelengths. For example, ultraviolet …









