Kenji Lopez-Alt became a rock star of the food world by bringing science into the kitchen in a way that everyday cooks can appreciate. Then he dared to start his own restaurant — and discovered problems that even science can’t solve.

The U.N.’s World Happiness Report — created to curtail our unhealthy obsession with G.D.P. — is dominated every year by the Nordic countries. We head to Denmark to learn the secrets of this happiness epidemic (and to see if we should steal them).