Archimedes Lever

"Give me a lever long enough and a fulcrum on which to place it, and I shall move the world".

Source: Archimedes

A lever is a simple mechanical device that can amplify a small amount of force to do a large amount of work. Take it to the extreme, Archimedes Lever is the idea that certain actions that do not seem significat by themselves can nevertheless change the world when applied properly.