The Extension of Man: A History of Physics Before the Modern Age

J.D. Bernal's 1972 history of physics from prehistoric times through the 19th century, tracing how tools and instruments — the lever, the lens, the clock, the steam engine — literally extended human capabilities and reshaped civilisation. Bernal, a crystallographer and polymath, argues that physics advanced not through pure thought but through the interplay between practical problems (navigation, mining, war) and the instruments built to solve them. The book is less a chronology of theories than a history of measurement: how humans learned to see farther, measure more precisely, and control more power.

Graham lists The Extension of Man in 'RAQs' as one of 'the most exciting [history books] I can think of,' alongside Clark's Civilisation and White's Medieval Technology and Social Change. The common thread across Graham's recommended history shelf is a materialist view of progress: ideas follow tools, not the other way around.

For a founder, Bernal's framing — that human progress is the story of extending our physical and cognitive reach through instruments — is a useful lens for product thinking. What instrument does your startup build that extends someone's capability? Bernal's history shows that the most transformative technologies are not the ones that solve a single problem but the ones that become platforms for solving problems no one had imagined yet. The telescope was not built to discover Jupiter's moons; it was built to aim at ships. The platform effect was a byproduct. Founders should ask: what platform will our instrument become?