Our Mathematical Universe: My Quest for the Ultimate Nature of Reality

by Max Tegmark

Changes in our human society result from a complex set of forces pushing in different directions, often working against each other. From a physics perspective, the easiest way to change a complex system is to find an instability, where the effect of pushing with a small force gets amplified into a major change. For example, we saw that a gentle nudge to an asteroid can prevent it from hitting Earth a decade later. Analogously, the easiest way for a single person to affect society is by exploiting an instability, as captured by numerous physics-based metaphors: an idea can be a “spark in a powder keg,” “spread like wildfire,” have a “domino effect,” or “snowball out of control.”1 For example, if you want to tackle the existential risk from killer asteroids, the hard way is to build an asteroid deflector–rocket system. The easier way is to spend much less money building an early-warning system, knowing that once you have information about an incoming asteroid, raising money for the rocket system will be easy.