Book Excerpt

What is the future of the like button in the age of artificial intelligence? Max Levchin—the PayPal cofounder and Affirm CEO—sees a new and hugely valuable role for liking data to train AI to arrive at conclusions more in line with those a human decisionmaker would make. It’s a well-known …

We all want to know if and how we can come back to form after injury, illness, or a long hiatus. Muscles adapt in response to the environment: They grow when we put in the work and shrink when we stop. But what if we could help them remember how …