[IAEP] Physics

[Edward Cherlin]

Thanks, Alan. Your workshop presentation omitted a lot of this, and I
only modeled the parts I knew about.

The Galileo moment is indeed central. I first encountered a different
application of this particular idea at the age of ten or eleven, in a
class at the Newark Museum (Newark, NJ). Balance a yardstick at its
center and hold it so that it can rotate in a horizontal plane. Put a
quarter on each end. Hit one end so that the quarter flies out level,
but the other quarter drops straight down when the yardstick moves out
from under it. Listen. The two quarters land at the same time.
Sideways motion has no effect on downward acceleration.

This is another instance of Galilean Relativity, the principle that
the laws of physics in the constant gravity approximation don't depend
on the reference frame for inertial motion until changing distances
between large bodies become significant. Newtonian Relativity then
follows, until the speed of light becomes significant in our
measurements, and Einstein's Special Relativity holds from there until
sufficiently large masses come into the picture. We have not yet found
any observable phenomena outside the range of General Relativity yet,
although we have hints of places to look, and have in fact looked in
some of those places.

Your point about guided discovery learning is central.

On Wed, Jul 1, 2009 at 5:35 AM, Alan Kay<alan.nemo at yahoo.com> wrote:
> Hi Ed,
>
> One sidelight on this activity is that it was originally thought up for
> junior high and high school, but Kim Rose and the teacher we were working
> with wanted to try it on the 5th graders. My main advice -- given that it
> had more parts to it than most things which work with 5th graders -- was to
> spread out the various parts of the exercise.
>
> An important part of "ball drop" was the separation of 3-4 months between
> "the math" (scripting various kinds of motion for the children's painted
> cars and dropping markers to reveal the history of their motion), and "the
> science" (handling various 3-4" spherical objects ranging from fruits to
> sponge and croquet balls, and two weights of shotputs; speculating on how
> they would fall relative to each other, coming up with ways to determine
> this, and then a range of experiments in which the janitor dropped the
> objects.
>
> The kids orginally chose stopwatches as a way of determining, but these
> don't work well (when did the janitor open his hands, what's the delay
> between the object hitting the ground and stopping the watch?). But we've
> found that in a class of 30 children there will be at least one "Galileo
> child" who will see that what should be done is to drop a heavy and light
> ball at the same time and *listen* to the impact. (This surpasses the
> approaches of both Aristotle and Acquinas).
>
> We take a video of the drops, and because a movie is just another object in
> Etoys, it can be taken apart (every 5th frame for example), and irrelevant
> parts of the frame can be painted transparent so the frames can be stacked.
> This makes it easy to see that the dropped object is not in uniform motion.
> Most of the kids immediately shout out "acceleration!" because they can see
> that the vertical pattern of movement of the dropped ball looks like one of
> the patterns of "history dots", from 4 months previously.
>
> This allows them to use "the math" in the form of two "increase by" scripts
> they wrote months earlier to help think about the pattern over time of the
> captured data.
>
> They do the measurements on the video frames to discover that the
> acceleration seems to be constant.
>
> Now to make a working model of the phenomena.
>
> They paint a simulated ball and realize they have to accelerate it in the
> vertical instead of horizontal direction.
>
> But this still isn't enough. How does their simulated ball movement script
> "match or miss" what was captured on the video? Most of the children will
> start trying to match the motions by trying different accelerations. For
> example, one child "Tyrone" (shown in the "Squeakers" CD explaining all
> this) decided to have his simulated ball leave dots behind so he could see
> if they corresponded with the frames of the movie showing the positions of
> the dropped object. The very close correspondence indicated that his
> constant acceleration script was a very close model of what was happening in
> the real world.
>
> The one thing we should have done is to try dropping other smallish heavy
> objects to see if this uniformly accelerated behavior is general for matter.
>
> However, I think you can see that the children were actually doing real
> science in all respects. They were not verifying some theory or assertion
> but were actually deriving it from the real world data. And they were making
> and excluding hypotheses all through the experiment.
>
> The separation between the car movement scripting and this experiment was
> long enough so it it counted as "math that could be used" but we didn't make
> any such suggestions, the children had to recall similarities from the past
> and rethink them in the light of the experimental context. Though the
> children had worked out the discrete differential models of motion 4 months
> previously, they still had to derive the math that seemed to fit the
> phenomena, and do the work to show the correspondence between their
> derivations and the phenonema.
>
> It's worth contrasting what and how here with the normal ways and the very
> different math used for high school and college. As I mentioned 70% of all
> college students fail to understand Galilean gravity, whereas we found that
> about 90% of the children were able to do much larger amount of work we
> required of them and were successful.
>
> I was pretty surprised at how well this worked with 10-11 year olds.
>
> The reasons this worked are:
>
> -- this is not "discovery learning" but "guided discovery learning" (where
> the guidance is not so much "socratic" as it is "montessoric", that is we
> put huge care into choosing the topics, history and environment, so that the
> children can do the main thinking without large distractions)
>
> -- we chose phenomena that are strongly in the child's world (this is hugely
> important when starting off).
>
> -- the math (as Papert showed long ago) of incremental discrete differential
> models that is so natural to computers which can retain and increment state,
> is perfect for children, because it involves only accumulative addition.
> This allows real thinking in differential relationships, and the "increase
> by" loops do the integration of these relationships. Papert's insight here
> is one of the great ideas in math and science education of all time.
>
> -- Etoys was not just set up for children doing the scripting, but it has
> the idea of leaving markers of various kinds (lines, dots, arrows, etc.) and
> while lines are the traditional "turtle trails", the dots and arrows can be
> much more illuminating and memorable for the children. (For 10-11 year olds
> -- and for lots of other ages -- remembering ideas about motion in turns of
> pictorial patterns is a great way to aid retention over long periods of
> time)
>
> -- we did this using the classroom teacher to do all of the helping and set
> up (But, we were there to make sure that real science was actually
> happening. This was facilitated by lots of meetings with the teacher outside
> of the classroom)
>
> Best wishes,
>
> Alan
>
> ________________________________
> From: Edward Cherlin <echerlin at gmail.com>
> To: Alan Kay <alan.nemo at yahoo.com>
> Cc: Caryl Bigenho <cbigenho at hotmail.com>; IAEP SugarLabs
> <iaep at lists.sugarlabs.org>
> Sent: Wednesday, July 1, 2009 12:40:46 AM
> Subject: Re: [IAEP] Physics
>
> On Tue, Jun 30, 2009 at 10:40 AM, Alan Kay<alan.nemo at 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 <cbigenho at hotmail.com>
>> To: IAEP SugarLabs <iaep at 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
>>
>>
>> _______________________________________________
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>> IAEP at lists.sugarlabs.org
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>>
>
>
>
> --
> 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)
>
>



-- 
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)