Many early attempts at tweaking gravity were easy to rule out, but Milgrom found a winning formula: When the gravitational acceleration felt by a star drops below a certain level — precisely 0.00000000012 meters per second per second, or 100 billion times weaker than we feel on the surface of the Earth — he postulated that gravity somehow switches from an inverse-square law to something close to an inverse-distance law.

“But now companies like Apple and Google have a responsibility to reduce these effects by converting intermittent variable rewards into less addictive, more predictable ones with better design. For example, they could empower people to set predictable times during the day or week for when they want to check “slot machine” apps, and correspondingly adjust when new messages are delivered to align with those times.”

“One characteristic of emergent change is that it seems impossible until it happens, at which point it feels overwhelming, sudden, and inevitable. The moment when water droplets and wind combine into a hurricane is one example. Another example is the moment when, at about 11:00pm Eastern Time in the United States, election predictions made a wild and irrevocable swing in favor of Trump.”