the.com/ripple effect

One small push, infinite strangers affected, zero of them invited to the meeting.

means A single action or event that spreads outward to cause a chain of further, often unforeseen, effects elsewhere.

from Straightforwardly visual: a pebble dropped in still water sends concentric rings outward from the point of impact. The physical phenomenon is ancient and obvious, but the phrase got lifted into figurative use — for social, economic, and emotional chains of consequence — mainly in the 20th century, as English liked borrowing water imagery for how one event 'spreads' through a system or community.

origin
literally from water circles spreading outward
economics term
describes how one job funds several others
chaos theory cousin
butterfly effect's more polite sibling
social proof
kindness shown to copy spreads three degrees out
the.com · every word