reverse textbook

one liner: offer a service that organizes all the concepts you need to know to understand a specific topic.

In our day and age, it really is impossible to understand everything in the world, it usually works much better if you only pick things up as you go. But in order to understand a high level concept, there are often prerequisites before you can understand the deeper stuff. The only good reference materials are usually textbooks and textbooks that are often pretty annoyingly big. You don't want to go through the whole physics book if you only want to understand how circuits work. It may require some knowledge about trigonometry and complex numbers, but you will probably not use differential equations. Trying to look up all these things gets quite annoying. It would be much better if you can have a customized "textbook" that isn't about a broad subject, like "physics," but all the information about a particular subject, like "microprocessor fabrication".

The service should be able to start with the topic that you do want to understand, and figure out all the necessary information that you would need to understand the topic completely. To implement it, it will be written like any textbook (probably like wikipedia) but with extra information about dependencies. When a user finds a topic to understand, the service will start with a common knowledge assumed that the user has, and build up lessons to work up to the topic. If the assumptions are wrong, the user can skip a topic or go into more fundamental topics.

I really think this is necessary, because there are a lot of smart educated people that want to learn about certain topics but get frustrated when they realize how hard it is to find a reliable source that you can understand. People shouldn't feel embarassed that they do not understand any given topic -- science is wayy to complicated for any one person to understand. Besides, a need based education will show people the practicality of the skills they are learning, rather than memorizing millions of equations that they will never use.