Wikipedia doesn't contain nearly enough knowledge. It tells you what a CPU is, not how to build one. It tells you some of the chemical properties of certain com

Wikipedia doesn't contain nearly enough knowledge. It tells you what a CPU is, not how to build one. It tells you some of the chemical properties of certain common chemicals, but not the millions of reactions, or thousands of entries in databases giving their exact physical and chemical properties, etc. Wikipedia would be a useful tool for bootstrapping, but is clearly a tiny, tiny fraction of human knowledge. It's short on a lot of technical details which fill the shelves and databases scientists, engineers, etc. depend on. It's also missing the living knowledge, that is passed from generation to generation as we teach people how to do the thousands of jobs that are necessary to keep modern society running.