While I did not ask the original question, I thank you, Alan, for these helpful hints to the pendulum problem.

Getting back to the imagined book in the subject line and my earlier question about whether such a resource exists: the reaction I have gotten from all the people with whom I have shared this problem and the hints is that they can understand the concepts but not the terminology...at least in this instance, it is the language that makes their eyes glaze over. I don't present this as a criticism, but, as someone concerned with explaining such things to people, it is definitely an important observation; one at least that I should keep in mind.

Best,

John

Hello Alan,

You hit it right on the mark with "vectors," but thinking back on it, the breakdown in communication may have been over the concepts themselves (despite claims to the contrary). I was discussing this with fellow computer club mentors and I seem to remember that even the illustrations you sent and your references to "weighing angle" and "'down track' forces" were greeted with blank looks. Without dwelling on this sad state of affairs, I simply want to point out that in "proselytizing" about Squeak we need to keep in mind that adults, even those in the biz, need the models just as much as kids; we can't assume an understanding even of simple math and physics.

Best,

J -----Original Message----- From: owner-squeakland@squeakland.org [mailto:owner-squeakland@squeakland.org]On Behalf Of Alan Kay Sent: Thursday, April 17, 2003 10:22 AM To: squeakland@squeakland.org Subject: RE: "All the Real Math To Which School (Including College) Refused Yo u Access."

Thanks John --

It would be great if you could list the "language stuff" that causes the glazing. Do you mean terms like "vectors"? What other terms are offputting? One of the reasons this stuff works so well with the kids is that they just do the models, we don't employ terminology with them.

Cheers,

Alan

At 8:29 PM -0400 4/16/03, John Voiklis wrote:

While I did not ask the original question, I thank you, Alan, for these helpful hints to the pendulum problem.

Getting back to the imagined book in the subject line and my earlier question about whether such a resource exists: the reaction I have gotten from all the people with whom I have shared this problem and the hints is that they can understand the concepts but not the terminology...at least in this instance, it is the language that makes their eyes glaze over. I don't present this as a criticism, but, as someone concerned with explaining such things to people, it is definitely an important observation; one at least that I should keep in mind.

Best,

John

--

Hi to everyone responding to my initial query about creating a pendulum in Squeak, specifically in the etoy environment. John has done a nice job of articulating the problem some of us are facing, namely, a weak background in physics and real mathematics. Kim suggests that creating Squeak models has helped her address this problem. i hope that's true (for me,anyhow), however, I'm feeling less than adequate when Alan suggests dealing with "weighing angle" and "'down track' forces" and vectors. Since no one responded to the query about the mathematics book that some of us need to read, I've resorted to going to my public library and borrowing a few introductory physics books (some from the children's room!). I'm off on a little vacation for the next week and i'll be taking the books along. I'll share my results if the books are helpful. Phil

On Thursday, April 17, 2003, at 12:17 PM, Kim Rose wrote:

Hi, John -

This is *so true*, and part of what makes "our job" that much more difficult. We can try to educate today's children to be in a better position to become teachers/mentors and adults tomorrow...but since today's teachers (adults in general) are often "victims of *their* education" they too remain mystified when it comes to ideas like "vectors". Many of today's adults never took a course in any physcial science, or as Alan likes to point out were never taugh mathematics, but only calculation. So, this does make it rough as you point out.

I will confess that *my* use of etoys and work in this area, has *finally* brought understanding to *me* of a few math and science concepts that remained "mysterious" until not so long ago. The good news with this experience is that I have personally seen how creating physcial models in this way can bring real learning. -- Kim

...

Hello Alan,

You hit it right on the mark with "vectors," but thinking back on it, the breakdown in communication may have been over the concepts themselves (despite claims to the contrary). I was discussing this with fellow computer club mentors and I seem to remember that even the illustrations you sent and your references to "weighing angle" and "'down track' forces" were greeted with blank looks. Without dwelling on this sad state of affairs, I simply want to point out that in "proselytizing" about Squeak we need to keep in mind that adults, even those in the biz, need the models just as much as kids; we can't assume an understanding even of simple math and physics.

Best,

J -----Original Message----- From: owner-squeakland@squeakland.org [mailto:owner-squeakland@squeakland.org]On Behalf Of Alan Kay Sent: Thursday, April 17, 2003 10:22 AM To: squeakland@squeakland.org Subject: RE: "All the Real Math To Which School (Including College) Refused Yo u Access."

Thanks John --

It would be great if you could list the "language stuff" that causes the glazing. Do you mean terms like "vectors"? What other terms are offputting? One of the reasons this stuff works so well with the kids is that they just do the models, we don't employ terminology with them.

Cheers,

Alan

At 8:29 PM -0400 4/16/03, John Voiklis wrote:

...

While I did not ask the original question, I thank you, Alan, for these helpful hints to the pendulum problem.

Getting back to the imagined book in the subject line and my earlier question about whether such a resource exists: the reaction I have gotten from all the people with whom I have shared this problem and the hints is that they can understand the concepts but not the terminology...at least in this instance, it is the language that makes their eyes glaze over. I don't present this as a criticism, but, as someone concerned with explaining such things to people, it is definitely an important observation; one at least that I should keep in mind.

Best,

John

--

--

That, for the most part, is the description I delivered to my peers yesterday. I will try it again with Alan's description in hand.

Thanks,

J

-----Original Message----- From: owner-squeakland@squeakland.org [mailto:owner-squeakland@squeakland.org]On Behalf Of Alan Kay Sent: Thursday, April 17, 2003 3:24 PM To: squeakland@squeakland.org Subject: RE: "All the Real Math To Which School (Including College) Refused Yo u Access."

I think lots of insight can be gained by seeing what the "weighing angles" illustration is all about.

Notice that when the angle is 90? the scale will measure the full weight of the dumbell and wheels. When the angle is 0?, the scale will show zero weight. In between, the scale will show the weight of the dumbell and wheels in the direction down the inclined plane. "Weight" is actually defined as the mass of an object times the force of gravity on it ( w = mg ). So what we are seeing on the scale is the differential effect of gravity down inclined planes at different angles.

If we use a protractor to tilt the inclined plane (say) every 5? then we can write down the different forces down the plane. If we divide these numbers by the maximum weight when the angle is 90, we will get numbers between 0 and 1. These numbers can be put into a holder as a table of values and used in a wide variety of projects, including making a roller coaster. So there is no need to use the idea of "sine" -- and this makes projects that need these ratios -- like roller coasters -- much more in the range of 5-7th graders.

Cheers,

Alan

At 11:49 AM -0400 4/17/03, John Voiklis wrote:

Hello Alan,

You hit it right on the mark with "vectors," but thinking back on it, the breakdown in communication may have been over the concepts themselves (despite claims to the contrary). I was discussing this with fellow

computer

club mentors and I seem to remember that even the illustrations you sent

and

your references to "weighing angle" and "'down track' forces" were greeted with blank looks. Without dwelling on this sad state of affairs, I simply want to point out that in "proselytizing" about Squeak we need to keep in mind that adults, even those in the biz, need the models just as much as kids; we can't assume an understanding even of simple math and physics.

Best,

J -----Original Message----- From: owner-squeakland@squeakland.org [mailto:owner-squeakland@squeakland.org]On Behalf Of Alan Kay Sent: Thursday, April 17, 2003 10:22 AM To: squeakland@squeakland.org Subject: RE: "All the Real Math To Which School (Including College) Refused Yo u Access."

Thanks John --

It would be great if you could list the "language stuff" that causes the glazing. Do you mean terms like "vectors"? What other terms are offputting? One of the reasons this stuff works so well with the kids is that they just do the models, we don't employ terminology with them.

Cheers,

Alan

At 8:29 PM -0400 4/16/03, John Voiklis wrote:

...

While I did not ask the original question, I thank you, Alan, for these helpful hints to the pendulum problem.

Getting back to the imagined book in the subject line and my earlier question about whether such a resource exists: the reaction I have gotten from all the people with whom I have shared this problem and the hints is that they can understand the concepts but not the terminology...at least

in

...

this instance, it is the language that makes their eyes glaze over. I

don't

...

present this as a criticism, but, as someone concerned with explaining

such

...

things to people, it is definitely an important observation; one at least that I should keep in mind.

Best,

John

--

--

Bert Freudenberg wrote:

...

If we use a protractor to tilt the inclined plane (say) every 5? then we can write down the different forces down the plane. If we divide these numbers by the maximum weight when the angle is 90, we will get numbers between 0 and 1. These numbers can be put into a holder as a table of values and used in a wide variety of projects, including making a roller coaster. So there is no need to use the idea of "sine" -- and this makes projects that need these ratios -- like roller coasters -- much more in the range of 5-7th graders.

What do you think of measuring the forces in the Etoy itself (for example, by taking the vertical extent of a rotated line)? Of course, I can see the value of using real-world data. Do you think it's too large a step to "see" the height of the angle, which is proportional to the force?

I think it would be nice to have a playground that had gravity "turned on", so all the stuff put in it would act acording.

Then you could "view" object and it would tell you the forces.

Karl

Hi Bert --

At 6:57 PM +0200 4/19/03, Bert Freudenberg wrote:

Am Donnerstag, 17.04.03 um 21:24 Uhr schrieb Alan Kay:

...

I think lots of insight can be gained by seeing what the "weighing angles" illustration is all about.

Notice that when the angle is 90? the scale will measure the full weight of the dumbell and wheels. When the angle is 0?, the scale will show zero weight. In between, the scale will show the weight of the dumbell and wheels in the direction down the inclined plane. "Weight" is actually defined as the mass of an object times the force of gravity on it ( w = mg ).

If I were picking nits I'd point out that actually weight is a force (measured in Newtons), not gravity. Force is mass times acceleration (Newton's second law). So in this special case, weight is mass times gravitational *acceleration*. Weight is only another term for gravitational force. But you knew that ;-)

...

So what we are seeing on the scale is the differential effect of gravity down inclined planes at different angles.

If we use a protractor to tilt the inclined plane (say) every 5? then we can write down the different forces down the plane. If we divide these numbers by the maximum weight when the angle is 90, we will get numbers between 0 and 1. These numbers can be put into a holder as a table of values and used in a wide variety of projects, including making a roller coaster. So there is no need to use the idea of "sine" -- and this makes projects that need these ratios -- like roller coasters -- much more in the range of 5-7th graders.

What do you think of measuring the forces in the Etoy itself (for example, by taking the vertical extent of a rotated line)? Of course, I can see the value of using real-world data.

I think this is really important at this stage. This is one of the relatively few phenomena that is both very interesting, useful, and measurable by the kids. This "weighing angles" idea cuts through a lot of steps and gets right to a way to determine the differential accelleration down the plane by directly referring to the phenomena.

Do you think it's too large a step to "see" the height of the angle, which is proportional to the force?

It shouldn't be too hard for adults ... heh heh. But kids are just learning about proportions (in the US they generally don't learn proportions successfully and operationally). I think this is a very good thing to point out after they have their simulated cars successfully going down different planes at the correct accellerations (Note that this can be done via one of the touch tests between the sim car and the sim plane.)

Cheers,

Alan

-- Bert