The historian examines the period concerning 1825 and 1918, in which four successive tsars confronted a Russian Modern society transferring swiftly towards revolution. Lucy discovers how the `Tsar-Liberator' Alexander II attempted to free countless serfs from slavery and examines the increase of radical writers and thinkers who sought to possess a

Tyson describes Halley's contributions dependant on Newton's work, together with determining Earth's length into the Sunshine, the movement of stars and predicting the orbit of then-unnamed Halley's Comet making use of Newton's rules. Tyson contrasts these scientific ways to understanding the galaxy in comparison with what earlier civilizations had