Random Notes from R. W. Hamming, Art of Doing Science and Engineering: Learning to Learn.

Richard W. Hamming. Art of Doing Science and Engineering. T&F STM. 1997.

It also comes from years of study of the work of others.

The belief anything can be "talked about" in words was certainly held by the early Greek philosophers, Socrates (469-399), Plato (427-347), and Aristotle (384-322). This attitude ignored the current mystery cults of the time who asserted you have to "experience" some things which could not be communicated in words. Examples might be gods, truth, justice, the arts, beauty, and love. Your scientific training has emphasized the role of words, along with a strong belief in reductionism, hence to emphasize the possible limitations of language I shall take up in several places in this book. I have already said that "style" is such a topic. ..This talking about first person experiences will give a flavor of "bragging," ... Vicarious learning from the experiences of others saves making errors yourself, but I regard the study of successes as basically more important than the study of failures. ... there are so many ways of being wrong and so few of being right, studying successes is more efficient, and furthermore when your turn comes you will know how to succeed rather than how to fail! you must think carefully about what you hear or read


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

In science, if you know what you are doing, you should not be doing it. In engineering, if you do not know what you are doing, you should not be doing it.

The past was once the future and the future will become the past. History is bunk. --Henry Ford, Sr.

1. History is seldom reported at all accurately, and I have found no two reports of what happened at Los Alamos during WW-II seems to agree. 2. Due to the pace of progress the future is rather disconnected from the past; the presence of the modern computer is an example of the great differences which have arisen.

Apparent contradictions:

1. You can simply ignore it.

2. You can admit it.

3. You can decide the past was a lot less determined than the historians usually indicate and individual choices can make large differences at times. ...

4. You can decide the future is less open ended than you would like to believe, and there is really less choice than there appears to be.

Unforeseen technological inventions can completely upset the most careful predictions.

No vision, not much of a future. What is possible? What is likely to happen? What is desirable to have happen? economics speed accuracy reliability rapidity of control freedom from boredom bandwidth in and out ease of retraining hostile environments personnel problems.

"The unexamined life is not worth living." Hamming quoting Socrates computer revolution

The purpose of computing is insight, not numbers. The purpose of computing numbers is not yet in sight.

A simulation is the answer to the question: "what if ...?" 1. cheaper, 2. faster, 3. often better 4. can do what you cannot do in the lab.

Why should anyone believe the simulation is relevant?

You are responsible for your decisions, and cannot blame them on those who do the simulations, as much as you wish you could. Reliability is a central question with no easy answers.

What you learn from others you can use to follow; What you learn for yourself you can use to lead.

Mathematics is nothing but clear thinking. Mathematics is the language of clear thinking.

Platonic school (most) formalists When rigor enters, meaning departs. logical school intuitionists constructionists fallacies: 1) we do not actually "prove" theorems! 2) many important programming problems cannot be defined sharply enough so a proof can be given, rather the program which emerges defines the problem!

Man is not a rational animal, he is a rationalizing animal.

"Luck favors the prepared mind." Hamming quoting Pasteur

An expert is one who knows everything about nothing; A generalist knows nothing about everything. In an argument between a specialist and a generalist the expert usually wins by simply (1) using unintelligible jargon, and (2) citing their specialist results which are often completely irrelevant to the discussion.

All impossibility proofs must rest on a number of assumptions which may or may not apply in the particular situation. "If an expert says something can be done he is probably correct, but if he says it is impossible then consider getting another opinion."

What you did to become successful is likely to become counterproductive when applied at a later date. "There is never time to do the job right, but there is always time to fix it later." especially in computer software.

Hamming's rule: 90% of the time the next independent measurement will fall outside the previous 90% confidence limits!

The first rule of systems engineering: If you optimize the components you will probably ruin the systems performance. rule 2: Part of systems engineering design is to prepare for changes so they can be gracefully made and still not degrade the other parts. rule 3: The closer you meet specifications the worse the performance will be when overloaded.

The rating system in its earlier stages may tend to remove exactly those you want at a later stage. popularity of a form of measurement has little relationship to its accuracy or relevance to the organization.

You get what you measure. 1. giving formal presentations, 2. producing written reports, 3. master the art of informal presentations as they happen to occur. Change does not mean progress, but progress requires change.

"For more than 40 years I have claimed that if whether an airplane would fly or not would depend on whether some function that arose in its design was Lebeques but not Riemann integratble, then I would not fly in it. Would you? Does Nature recognize the difference? I doubt it!"

"I know that the great Hilbert said, `We will not be driven out of the paradise Cantor has created for us,' and I reply, "I see no reson for walking in."

"In science and mathematics, we do not appeal to authority, but rather you are responsible for what you believe."

"With the enourmous growth of results at well over 100,000 (new?) theorems every year...the chance of a new piece of pure mathemaitcs being spotted by you and also being at hand when you need it, and not have not be recreated when needed, is increasing small ... Regeneration is increasingly easier than retrieval."