Only after the last fish has been caught. This section has topics on hazards to the environment and health. Hazards to our personal environment and our health. Isaac Newton, circa 1676. Newton's 'edge of the ocean' metaphor is particularly apt for describing scientific understanding of how biological systems function.
Scientists understand a great deal, but it is a drop in the ocean.
Biological hazards, such as the spread of DDT into the food chain, arose in part because of a lack of knowledge. The two knots were in an early systematic knot catalogue. They are both from the section of the catalogue for knots with ten crossovers. For fifty years the two knots were thought to be quite distinct. In fact one knot can be turned into the other by rearranging the parts.