Astrophysicists know an awful lot: for example, that 26 percent of the universe consists of dark matter and the black hole at the centre of galaxy M87 weighs as much as 6.6 billion suns. But how did they actually come by this knowledge? After all, no probe has ever left our solar system. Not to mention experiments in distant spiral nebulae. Are their claims mere speculation and might the universe actually look quite different?
The philosopher and astrophysicist Sibylle Anderl shows us how it is possible to measure the cosmos by means of observations and models alone. She explains the fascinating work of astronomers who, like master detectives, conclude from the smallest evidence, such as light spectrum or the movement of stars, what planets consist of and what is in the mass of black holes. Anderl’s book is a declaration of love for the exploration of the universe. And a fascinating philosophical journey to the limits of our knowledge.