My advice to young scientists who seek a sense of purpose in their research is to engage in a topic that matters to society, such as moderating climate change, streamlining the development of vaccines, satisfying our energy or food needs, establishing a sustainable base in space or finding technological relics of alien civilizations. Broadly speaking, society funds science, and scientists should reciprocate by attending to the public’s interests.
The most vital societal challenge is to extend the longevity of humanity. At a recent lecture to Harvard alumni I was asked how long I expect our technological civilization to survive. My response was based on the fact that we usually find ourselves around the middle part of our lives, as originally argued by Richard Gott. The chance of being an infant on the first day after birth is tens of thousand times smaller than of being an adult. It is equally unlikely to live merely a century after the beginning of our technological era if this phase is going to last millions of years into the future. In the more likely case that we are currently witnessing the adulthood of our technological lifespan, we are likely to survive a few centuries but not much longer. After stating this statistical verdict publicly, I realized what a horrifying forecast it entails. But is our statistical fate inevitable?
There is a silver lining lurking in the background. It involves the possibility that we possess free will and can respond to deteriorating conditions by promoting a longer future than a few centuries. Wise public policy could mitigate the risk from technological catastrophes associated with climate change, self-inflicted pandemics or wars.