Brief Answers to the Big Questions

The purpose of science is to discover truths about the phenomena of our lives—the nature of the world around us, how it works, and how we interact with it. Researchers report their findings in professional journals, textbooks, lectures, and sometimes news interviews and documentaries.

Scientists train carefully to leave their private prejudices at home and perform experiments with neutral dispassion. Other scientists vet their papers for accuracy and with special attention aimed at rooting out bias. This process itself can generate disagreements—given the challenge of devising a peer review system free of preconceptions—but for the most part works well enough to produce the knowledge that has helped advance our understanding of the universe.

Occasionally, scientists learn of something that may prove dangerous to humans and other life on Earth and understandably feel obligated to warn others. In recent decades, researchers have sounded the alarm about the dangers of cigarettes, climate change, pandemics, and future asteroid strikes. Even vaccines, long a mainstay of public health, sometimes undergo scrutiny. These warnings usually elicit sharp rebukes from people in differing places on the political spectrum.

The debates can be vitriolic and uncivil; members of the public begin to doubt scientists and even question their techniques of gathering knowledge. In the process, science itself comes under fire. Debates arise within science as colleagues accuse each other of taking political stands on issues that ought best be settled within the strict boundaries of the scientific method.

Hawking wrote and spoke extensively on such risks. More than once, he waded into controversies that touched on the politics of the age. Some of these beliefs appear in Brief Answers. They include his fear that humanity will destroy itself via nuclear weapons, a human-caused climate catastrophe, or artificial intelligence (AI) run amok. His proposals include carefully proceeding with AI development, colonizing other worlds to guarantee that some people will survive human-caused disasters, reviving nuclear power, and even experimenting with genetic engineering.

Hawking encourages people to ask probing questions, think for themselves, and speak their minds. He firmly believes in the duty of science to sound the alarm when it discovers dangers that threaten the world but bases his pronouncements on scientific data, not on emotional reasoning or biased motivations. He’s passionate about communicating what he has discovered yet always prepared to change his mind if the science points in another direction. His message is that people can solve almost any problem by using scientific reasoning and experimentation.