Hacker News new | ask | show | jobs
by gowld 1611 days ago
A "closed" circuit is just an open circuit plus a pump (electron pump or water pump).

Open circuits work fine if there is a powerful source of electricity (like a a radio) and a sink (like the Earth), and same for water (an icy comet crashing into a cliff, making a waterfall).

An open water circuit is full of stationary water.