On Tue, Jun 30, 2009 at 10:40 AM, Alan Kay<alan.n...@yahoo.com> wrote: > Hi Caryl, > > It's possible that the Physics Activity could get students interested in > Physics, but the deepest and most important parts of real science cannot be > learned from a book or a computer or from just doing mathematics no matter > how wonderful.
In Alan's third grade gravity lesson, which I have modeled using Turtle Art http://wiki.sugarlabs.org/images/0/0e/Gravity.odt he has students build a model, and then look at something in the physical world that matches the model. We have three things here, as a necessary but not sufficient base for a very small part of physics: o model o phenomenon o correspondence We have to work at all three in order to have a scientific theory. From the mass of phenomena, we have to select something repeatably observable in unconfined Nature or in lab experiment. From the wild profusion of mathematical forms, we have to select something from which we can build a correspondence with our observations, making appropriate allowance for the imprecision of our measurements. We must consider all available models and correspondences in order to design experiments that show that one set works better than another over a wider range. But in this lesson we are giving the students all three of these elements, with none of the accompanying questions or work. They are not discovering anything new, nor are they doing any of the work of excluding other hypotheses, or of verifying the range of validity of the model. > The notion that they can has been a major misconception for thousands of > years, and is shockingly widespread in the US educational system. This is > because all representation systems we use, including the ones inside our > heads, are ultimately hermetic, and thus in the end are only about > themselves. See David Hume, A Treatise of Human Nature, for the best exposition of this fact. > Science is a kind of negotiation between our representation systems and > "what's out there?". And the negotiation is always there. As Richard > Feynmann liked to say "Science means you don't have to trust the experts". o representation system = model o "what's out there?" = phenomenon o negotiation = dynamic improvement of correspondences over time > This is why books, computers, math, etc., don't work. Because natural > languages and math have negation, we can write just anything in a book. Whereas, as Galileo noted, the Book of Nature does not contradict itself. If it seems to us that it does, it is our fault, which we must strive to correct. We have misunderstood.The abandoning of the idea of a Luminiferous Ether is a clear example of what we have to do, and how hard that is. > Because math depends on premises taken as given (called definitions in > modern math) we can make a perfect logical system that has nothing to do > with "what's out there?" (and many people have over the ages). But surprisingly often, one or another of these logical systems do turn out to correspond with what we can observe of "what's out there?". Galileo worked in Euclidean geometry. Newton had sharper tools, but was able to expound the results in pure Euclidean geometry. Einstein had non-Euclidean spacetime and tensors. The latest physical theories have to do with such things as Lie groups. (The rotations of a sphere are a simple example of a Lie group. Other have to do with rotations of spaces we cannot visualize.) > Because we can make detailed maps of places which have never existed (e.g. > Middle Earth) and can make perfect deductions from them (Gondor is North of > Far Harad, and the Shire is North of Gondor, therefore the Shire is North of > Far Harad, etc.) we have no way at all of knowing whether this map > represents any thing "out there" or not unless we actually exhaustively look > for it. String Theory, among other recent ideas, suggests that there may be extra dimensions to spacetime. The math cannot possibly tell us how many dimensions there are in reality, because there are too many options. But working with the math can suggest where to look for experimental opportunities to find out. > Telling children to learn what is in a book or computer model is absolutely > no different from telling them to learn this catechism or that one. They > have to be grounded in learning to deal with the actual world in ways that > get around what's wrong with our perceptual systems and the minds attached > to them. There are a number of critical experiments that children can do to anchor their learning to the real world. They need those anchors at as many points as possible in order to be able to think about how to apply physical theory to practical problems or to research. Richard Feynman's description of physics education in Brazil is the best example I know of for how to do it wrong. Surely You're Joking, Mr. Feynman, pp. 216 ff.: "The main purpose of my talk is to demonstrate to you that _no_ science is being taught in Brazil!" It was all theory, with no anchors. Students memorize the definition of, say, diamagnetism, and the rules for calculating with it, but never learn what materials are diamagnetic. Teachers and students are unaware of this lack, because the system they work in appears to be internally consistent and logically complete. But it consists entirely of a model, with no phenomena and no correspondences. You can't use it for anything except teaching more of it. > Because scientific knowledge is now large, it is not possible to learn all > of science from doing personal experiments. The major point here is that the > "outlook" (simple name for "epistemological stance") of science has to be > internalized before one can understand just how to garner scientific > knowledge from writings rather from the real world. This means, among other things, being able to analyze the experimental design and the data described in a scientific paper, looking for holes. > Scientists (not just science teachers) have trouble with this, because our > brains/minds are set up to believe not to understand or doubt. For example, > in spite of the fact that the Victorian Brits considered Maxwell their best > scientist (he was) they could not find it possible to get into Maxwell's > Equations, in large part because they were non-Newtonian, and Newton had > been made into a god that exemplified the "master race" that all such > cultures love to think they are. And they were not going to go against their > god. As a result, it was left to several prominent Germans, including > Heinrich Hertz, to experiment with the ideas in the equations and to invent > and build the first radio transmitter. Even in Germany, Einstein complained, nobody would teach it for decades after. > The fact that this happens doesn't make it excusable, but it does illustrate > how hard real science is to really do -- and how difficult it is to teach > and learn. It is vital to study the processes of misunderstanding and partial understanding, of designing critical experiments to "falsify" theories, and much more. It is also necessary to have the kind of imagination that makes it possible to understand a state of mind other than one's own at the moment, and to think of alternatives to currently accepted views, including what you believe yourself. These skills, like most, are partly a matter of talent and partly a matter of practice. As with music, few can become professionals of the highest rank, but all can attain basic competence if competently taught. > Very best wishes, > > Alan > > > ________________________________ > From: Caryl Bigenho <cbige...@hotmail.com> > To: IAEP SugarLabs <iaep@lists.sugarlabs.org> > Sent: Tuesday, June 30, 2009 9:21:54 AM > Subject: [IAEP] Physics > > > Hi All, > I sent this yesterday, but it got filtered out by some machine since I > didn't send it as a "reply". So I am sending it again today. > > This is the "old science teacher" in me talking...I think the Physics > Activity has great potential for getting students interested in Physics and > in thinking like scientists. I watched a 13-year-old girl play with it at > the Bozeman LUG meeting last week. She loved experimenting with the shapes > to see what they would do. > How do scientists think and work? They observe, take notes, make > predictions (hypotheses) test them, and repeat. This program is perfect for > that! We need someone to design some simple experiments tied to curriculum > goals that will help students of various levels enjoy "playing scientist" > with the Physics Activity as they learn a tiny bit about physics and a lot > about thinking like a scientist. > > I haven't played enough to know what all is included in the Activity. Does > it have, for example, the option of changing the "material" an object is > "made of"? > > Caryl > > > _______________________________________________ > IAEP -- It's An Education Project (not a laptop project!) > IAEP@lists.sugarlabs.org > http://lists.sugarlabs.org/listinfo/iaep > -- Silent Thunder (默雷/धर्ममेघशब्दगर्ज/دھرممیگھشبدگر ج) is my name And Children are my nation. The Cosmos is my dwelling place, The Truth my destination. http://earthtreasury.org/worknet (Edward Mokurai Cherlin) _______________________________________________ IAEP -- It's An Education Project (not a laptop project!) 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