Einstein had no fear of ideas that weren’t common-sensical: “[T]his set him free to be ingenious, a genius of his time and every other” (199). Einstein’s imagination soared across the universe to discover the strange truths hidden beneath appearances. Likewise, Hawking let his mind roam to the edges of the cosmos as he searched for answers to our most basic questions about reality.

Teachers and education are critical to new advances: “If you look behind every exceptional person there is an exceptional teacher” (201). Recent economic problems have caused many nations to curtail science training—and to tighten national borders, which stifles the free exchange of ideas. Schools often disenchant bright kids by imposing rote learning; most people don’t read popular science books, and few see science documentaries. Nevertheless, future humans will be more dependent on science than any generation before them.

Humanity hasn’t reached the pinnacle of its possibilities; in fact, Hawking sees no limit to what we can achieve. We can address Earth’s environmental and resource crises through space colonization and through the careful use of AI, realizing that AI might ignore or harm us unless we work harmoniously with it.

Already, technology has made astounding strides that have helped humanity. Better communication, solutions for people with disabilities, and the vast increase and dispersal of information offer hope for the future.