The speed that the a ship was sailing as was measured by throwing a log overboard attached to a knotted rope. Then the knots were counted, and the time measured.

The result of this exercise was written in the logbook by the captain: Critical information by which they navigated. The logbook kept track of what happened so that they could safely navigate the vast oceans.

When we do work we can also throw out a log, and count the knots as they dissapear. We can also keep a log book of all our actions, results, and active question.

The logbook keeps track of what happened so that we can explore uncertainty safely.