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January 12 - January 28, 2023
Teachers should prepare the student for the student’s future, not for the teacher’s past.
Education is what, when, and why to do things. Training is how to do it.
How are you to recognize “fundamentals”? One test is they have lasted a long time. Another test is from the fundamentals all the rest of the field can be derived by using the standard methods in the field.
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.
Of course, you seldom, if ever, see either pure state. All of engineering involves some creativity to cover the parts not known, and almost all of science includes some practical engineering to translate the abstractions into practice.
unforeseen technological inventions can completely upset the most careful predictions,
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 . 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.
Drunkard’s walk
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 have 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 ensemble of all possible futures. The third is ethics, morals, or whatever other word you wish to apply to value judgments.
Lastly, in a sense this is a religious course: I am preaching the message that, with apparently only one life to live on this earth, you ought to try to make significant contributions to humanity rather than just get along through life comfortably—that the life of trying to achieve excellence in some area is in itself a worthy goal for your life.
It has often been observed the true gain is in the struggle and not in the achievement—a life without a struggle on your part to make yourself excellent is hardly a life worth living.
In ancient Greece, Socrates (469–399 bc) said: The unexamined life is not worth living.
transmission through space (typically signaling) is the same as transmission through time (storage).
It has rarely proved practical to produce exactly the same product by machines as we produced by hand.
The more complex the designed system, the more field maintenance must be central to the final design. Only when field maintenance is part of the original design can it be safely controlled; it is not wise to try to graft it on later. This applies to both mechanical things and to human organizations.
The purpose of computing is insight, not numbers.
History tends to be charitable in this matter. It gives credit for understanding what something means when we first do it. But there is a wise saying, “Almost everyone who opens up a new field does not really understand it the way the followers do.”
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.
the duty of a scientist is not only to find new things, but to communicate them successfully in at least three forms: Writing papers and books Prepared public talks Impromptu talks
Perhaps “thinking” is not a yes/no thing, but maybe it is a matter of degree.
You must struggle with your own beliefs if you are to make any progress in understanding the possibilities and limitations of computers in the intellectual area. To do this adequately you must formalize your beliefs and then criticize them severely, arguing one side against the other, until you have a fair idea of the strengths and weaknesses of both sides.
Whatever your opinion is, what evidence would make you accept you are wrong?
Rule: Huffman coding pays off when the probabilities of the symbols are very different, and does not pay off much when they are all rather equal.
Working calmly will let you elaborate and extend things, but the breakthroughs generally come only after great frustration and emotional involvement. The calm, cool, uninvolved researcher seldom makes really great new steps.
Pasteur says, “Luck favors the prepared mind.”
When you decide something is not possible, don’t say at a later date it is still impossible without first reviewing all the details of why you originally were right in saying it couldn’t be done.
Moral: to the extent you can choose, work on problems you think will be important.
In closing, if you do not, now and then, doubt accepted rules, it is unlikely you will be a leader into new areas; if you doubt too much you will be paralyzed and will do nothing.
When to doubt, when to examine the basics, when to think for yourself, and when to go on and accept things as they are is a matter of style, and I can give no simple formula on how to decide.
Intellectual shelf life is often more insidious than is physical shelf life.
Hamming’s law: “You cannot consume what is not produced.”
Simpson’s paradox is a famous example, where both subsamples can favor A over B and C, but the combined data favors B over A.
There is another important factor, known as the Hawthorne effect, that it is necessary to explain.
What you learn from others you can use to follow; What you learn for yourself you can use to lead.
Mathematics is the language of clear thinking.
Hilbert’s claims, “When rigor enters, meaning departs.”
The nature of our language tends to force us into “yes/no”; something is or is not, you either have a proof or you do not. But once we admit there is a changing standard of rigor, we have to accept that some proofs are more convincing than other proofs. If you view proofs on a scale much like probability, running from 0 to 1, then all proofs lie in the range and very likely never reach the upper limit of 1, certainty.
If an expert says something can be done he is probably correct, but if he says it is impossible then consider getting another opinion.
Do not just drift along; think of what you want to be and how to get there. Do not automatically reject every crazy idea the moment you hear of it, especially when it comes from outside the official circle of the insiders—it may be the great new approach which will change the paradigm of the field!
No matter how sacred the data and urgent the answer, I have learned to pretest it for consistency and outliers at a minimum.
90% of the time, the next independent measurement will fall outside the previous 90% confidence limits!
Hamming’s rule
The first rule of systems engineering is: If you optimize the components, you will probably ruin the system performance.
Part of systems engineering design is to prepare for changes so they can be gracefully made and still not degrade the other parts.
The closer you meet specifications, the worse the performance will be when overloaded.
I suppose the heart of systems engineering is the acceptance that there is neither a definite fixed problem nor a final solution, rather evolution is the natural state of affairs.
The deeper, long-term understanding of the nature of the problem must be the goal of the systems engineer, whereas the client always wants prompt relief from the symptoms of his current problem.
You get what you measure
the way you choose to measure things controls to a large extent what happens.
The rating system in its earlier stages may tend to remove exactly those you want at a later stage.
There is always a tendency to grab the hard, firm measurement, though it may be quite irrelevant as compared to the soft one, which in the long run may be much more relevant to your goals.
Accuracy of measurement tends to get confused with relevance of measurement, much more than most people believe. That a measurement is accurate, reproducible, and easy to make does not mean it should be done; instead, a much poorer one which is more closely related to your goals may be much preferable.
