“The great advantage of the fountain pen is that it is slow. Ideas come faster than we can serialize them to paper. Therefore, the ideas are stored in an “accumulation buffer” in the brain. When in the buffer, the ideas interact and purify. If we empty the buffer too soon, we don’t give the ideas enough time to mature and we get half-baked prose.

Code badly written the first time remains buggy and filled with holes no matter how much it is debugged.

“Given the choice between an extremely skilled loner and a competent-but-social programmer, XP teams consistently choose the more social candidate.

“Lispers are not smarter, they just fell into a pool and learned to swim. Nothing to hold them up, they had to make do in a medium that would not support them, they had to add energy just to stay afloat.

“When a CEO says to Congress, “Our industry relies on chemical X and we’re going to keep using it as long as our competitors do, so please ban it,” she creates a long-term path to stability and growth.

“1 selenium test for every 10 controller tests for every 100 model tests.

“Engines are usually designed bottom-up. First it is necessary to thoroughly understand the properties and limitations of the materials to be used (for turbine blades, for example), and tests are begun in experimental rigs to determine those. With this knowledge larger component parts (such as bearings) are designed and tested individually. As deficiencies and design errors are noted they are corrected and verified with further testing. Since one tests only parts at a time these tests and modifications are not overly expensive. Finally one works up to the final design of the entire engine, to the necessary specifications. There is a good chance, by this time that the engine will generally succeed, or that any failures are easily isolated and analyzed because the failure modes, limitations of materials, etc., are so well understood. There is a very good chance that the modifications to the engine to get around the final difficulties are not very hard to make.

The Space Shuttle Main Engine was handled top down, we might say. The engine was designed and put together all at once with relatively little detailed preliminary study of the material and components. Then when troubles are found in the bearings, turbine blades, coolant pipes, etc., it is more expensive and difficult to discover the causes and make changes.