10 January 2014

What does "why" mean?

The following short clip shows Richard Feynman answering the question why two magnets attract or repel one another. The person asking the question is trying to understand why he has this feeling when he holds two magnets close to one another.

Feynman answers the question by not answering it! It is brilliant. He says that in order to answer the question he must know what the truth basis of the person asking it is. He digresses giving a number of interesting examples. He says that a first-order answer, such as "it's due to the magnetic force", may satisfy the person who asked but may not be an answer at all. A second why may follow, and a third, and so on. (Does the guy know what a magnetic force is? Is this not just a reduction of the problem to another problem?) A basis for truth must be known before the question can be answered. Feynman points out that the `magnetic force' (whatever this is) is intimately related to the `electric force' (whatever this is) and that the two are, essentially the same. (A consequence of a happy marriage of Electromagnetism and Relativity. In fact, the latter was borne because of the first.) But, Feynman continues, when the guy asking the question rests his arm on the chair he doesn't ask (or even think that he could ask!) why the arm doesn't go inside the chair. Ultimately, it's an electric force keeping the arm where it is, but it does not seem as `unnatural' as a magnet. They are, however, the same kind of forces. So, he concludes, he can't answer his question, because, clearly, the person asking has no basis for understanding it.

Watch the video and read some more comments below.

As an electrical engineer and mathematician, I find these things quite natural. This is due to the things I learned in the university and to the work I did. I am also puzzled as to how to explain certain concepts to people who want to know but who have no time or desire for a bit deeper studies. One can give `popular' answers, but over-popularizing is always--to some degree--cheating.

You may (correctly) argue that I shouldn't expect a lay person to study relativity before he or she can understand the answer. No. But I would expect an academic  to have the scientific curiosity (and integrity) to learn further.

Another thing that comes to mind when listening to Feynman's `explanation' is the word `pedagogy'. For several years now, universities (especially in certain parts of Europe) keep getting infested  by a new species of people who claim to have answers to all `pedagogical questions'. In fact, they are so sure of themselves, that they have convinced universities that they should train others on the matter. And yet, they themselves cannot answer simple, pedagogical, questions. The example above is perfect. One would expect that a lecturer in Physics ought to be know what Feynman is talking about, including the meaning of `why'. Traditionally, teachers learn these things by `doing' teaching, by practice. Now, if the species of pedagogues wants to train a teacher in physics, then one would expect that the pedagogue would be in position to teach what Feynman has in mind. Alas, this never happens. Pedagogical courses are, by and large, void of content. I've seen young guys and gals suffer in the UK by the pedagogical training they receive. I've been to pedagogical courses in Sweden with absolutely no content. Hours of wasted time, Nobody has ever gone to a pedagogical class watching, for instance, a Feynman lecture. Why, in order that this happen, the pedagogues themselves must be in a position to understand what Feynman is talking about, from a pedagogical point of view. Unfortunately, pedagogical classes teachers seem to have no qualifications other than dissemination of bureaucracy. (Example: they train teachers how to fill in forms. It's absurd and obscene.)


  1. Fascinating video, thanks Takis!

    I escaped the kind of training you're describing. Mostly I'm glad of that.... But some things I would still appreciate - for example, someone to observe me lecturing, and comment.


  2. James, I TOTALLY agree with you. I'd LOVE to have a colleague or someone (who understands, to some degree, the content of my lectures) be there, in class, with me. This should be a continuing process, say, once every 2 years (?), and not a one-time shot. But this is not what is happening in pedagogical courses. Typically, ONCE in one's career, some "pedagogue" watches a person lecture, and that's it. This is supposed to take care of everything.

    I've also escaped all that. (I guess they thought that I learned everything in the US...) I'm not complaining about myself, but about the so-to-speak pedagogical education which, according to people who are really interested in the pedagogical aspects of technical teaching, is flawed and tends to ignore a basic principle: namely, that it is impossible to have a pedagogical education common and uniform across all disciplines, from mathematics to applied botanics.

  3. Loved the Feynman clip.
    He did answer the question, by showing what must be understood by the listener before his question could be meaningful.

  4. Yes, yes. It's fantastic. Have you read his book "The Character of Physical Law"? Highly recommended.

    Some of Feynman's lectures should be part of any pedagogical training of university teachers, not only in Physics.



What measure theory is about

It's about counting, but when things get too large.
Put otherwise, it's about addition of positive numbers, but when these numbers are far too many.

The principle of dynamic programming

max_{x,y} [f(x) + g(x,y)] = max_x [f(x) + max_y g(x,y)]

The bottom line

Nuestras horas son minutos cuando esperamos saber y siglos cuando sabemos lo que se puede aprender.
(Our hours are minutes when we wait to learn and centuries when we know what is to be learnt.) --António Machado

Αγεωμέτρητος μηδείς εισίτω.
(Those who do not know geometry may not enter.) --Plato

Sapere Aude! Habe Muth, dich deines eigenen Verstandes zu bedienen!
(Dare to know! Have courage to use your own reason!) --Kant