Complex Systems.

Shared resources depend on both individual demand and the rules people build together.

Local preferences can produce a larger pattern that nobody explicitly chose.

Tiny differences in starting conditions can grow into very different trajectories.

The shape of a response determines whether variation helps or hurts.

Repeating a bit can overcome some errors but uses extra capacity.

Contact and recovery rates change the shape of an outbreak in a closed population.

Growth slows as a population approaches a finite capacity.

Two interacting populations can rise and fall out of phase.

A very small population may struggle to recover even when resources are available.

A small change in visible adoption can trigger a larger collective shift.

For some things, the longer they have lasted, the longer they may last.

A small number of outcomes can account for a very large share of the whole.

Some things become more useful when more people use them.

When does an average across many worlds describe one journey through time?