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Highlights: The Art of Doing Science and Engineering

"The Art of Doing Science and Engineering" by Richard Hamming, 1996.

Teachers should prepare the student for the student's future, not for the teachers past. Most teachers rarely discuss the important topic of the future of their field, and when this is pointed out they usually reply: "No one can know the future." It seems to me the difficulty of knowing the future does not absolve the teacher from seriously trying to help the student to be ready for it when it comes. xx

Education is what, when, and why to do things. Training is how to do it. 4

The reason why back-of-the-envelope calculations are widely used by great scientists is clearly revealed—you get a good feeling for the truth or falsity of what was claimed, as well as realize which factors you were inclined not to think about, such as exactly what was meant by the lifetime of a scientist. Having done the calculation you are much more likely to retain the results in your mind. Furthermore, such calculations keep the ability to model situations fresh and ready for more important applications as they arise. 7

It is well known the drunken sailor who staggers to the left or right with n independent random steps will, on the average, end up about √n from the origin. But if there is a pretty girl in one direction, then his steps will tend to go in that direction and he will go a distance proportional to n. In a lifetime of many, many independent choices, small and large, a career with a vision will get you a distance proportional to n, while no vision will get you only the distance of √n. In a sense, the main difference between those who go far and those who do not is some people have a vision and the others do not and therefore can only react to the current events as they happen. 12

For many years I devoted about 10% of my time (Friday afternoons) to trying to understand what would happen in the future of computing, both as a scientific tool and as a shaper of the social world of work and play. In forming your plan for your future you need to distinguish three different questions: What is possible? What is likely to happen? What is desirable to happen? ... In a sense the first is science—what is possible. The second is engineering—what are the human factors which choose the one future that does happen from the the ensemble of all possible futures. The third is ethics, morals, or whatever other word you wish to apply to value judgments. 13

It has been said that in physics no creator of any significant thing ever understood what he had done. I never found Einstein on the special relativity theory as clear as some later commentators. And at least one friend of mine has said, behind my back, "Hamming doesn't seem to understand error correcting codes!" He is probably right; I do not understand what I invented as clearly as he does. The reason this happens so often is the creators have to fight through so many dark difficulties, and wade through so much misunderstanding and confusion, they cannot see the light as others can, now the door is open and the path made easy. 51

...I would think by the year 2020 it would be fairly universal practice for the expert in the field of application to do the actual program preparation rather than have experts in computers (and ignorant of the field in question) do the program preparation. 55

As we say, the volume is almost all on the surface. Even in three dimensions the unit sphere has 7/8 of its volume within 1/2 of the surface. In n dimensions there is 1-1/2^n within 1/2 of the radius from the surface. This has importance in design; it means almost surely the optimal design will be on the surface and will not be inside...generally speaking, the best design is pushing one or more of the parameters to their extreme—obviously you are on the surface of the feasible region of design! 116

We use computers to do simulations because they: 1. are cheaper, 2. are faster, 3. are often better, and 4. can do what you cannot do in the lab. 234

But let lab equipment lie idle for some time, and suddenly it will not work properly! This is called "shelf life," but it is sometimes the shelf life of the skills in using it rather than the shelf life of the equipment itself! I have seen it all too often in my direct experience. Intellectual shelf life is often more insidious than is physical shelf life. 235

Why should anyone believe the simulation is relevant? Do not begin any simulation until you have given this question a great deal of thought and found appropriate answers. Often there are all kinds of reasons given as to why you should postpone trying to answer the question, but unless it is answered satisfactorily, then all that you do will be a waste of effort, or, even worse, either misleading or even plain erroneous. The question covers both the accuracy of the modeling and the accuracy of the computations. 246

There is another important factor, known as the Hawthorne effect that is necessary to explain. At the Hawthorne plant of Western Electric, long, long ago, some psychologists were trying to improve productivity by making various changes in the environment. They painted the walls an attractive color, and productivity rose. The made the lighting softer, and productivity rose. Each change caused productivity to rise. One of the men got a bit suspicious and sneaked a change back to the original state, and productivity rose! Why? It appears that when you show you care, the person on the other end responds more favorably than if you appear not to care. The workers all thought the changes were being made for their benefit and they responded accordingly. 287

...after I had been eating for some years at the physics table at the Bell Telephone Laboratories restaurant, fame, promotion, and hiring by other companies ruined the average quality of the people, so I shifted to the chemistry table in another corner of the restaurant. I began by asking what the important problems were in chemistry, then later what important problems they were working on, and finally one day said, "If what you are working on is not important and not likely to lead to important things, then why are you working on it?" After that I was not welcome and had to shift to the eating with the engineers! That was in the spring, and in the fall one of the chemists stopped me and said, "What you said caused me to think for the whole summer about what the important problems are in my field, and while I have not changed my research it was well worth the effort." 389