New rendering testing

[James Hurley]

Al,

This all started while was teaching at the university and working with a local grade school teacher. At that time Logo was all the rage and I thought it would be an ideal language in which young children might solve interesting physics problems, essentially implement numerical methods to solve differential equations. In Turtle Graphics for example a trajectory script looks like this:

 repeat until ycor() < 0
    incXY vx,vy -- Increment the x and y coordinates by vx and vy every second
    subtract gravity from vy
 end repeat

I wrote a book titled "Logo Physics" which is now out of print but available, used, on Amazon. (I was proud to see just now that one vender has for sale at $129.)

The very attractive element of Logo was what became knows as Turtle Graphics. (LOGO itself was modeled on LISP.) It was developed at MIT by Symour Papert et. al. I was talking to them at the time.

Later, I wrote a translator for TG in HyperTalk. There are several version of it at:  http://jamesphurley.com/runrev.html

There are a large number of applications there.

Kevin and I discussed the possibility of implementing it as part of Run Rev. They were more interesting in education at the time.

I'm not sure where that file you found came from, but it is not very readable. I have a clean version I will send you separately. Do not share it with others at this time. I have retitled (and did some rewriting of)  the Logo Physics book to "Programming for Science Students." I think that is the appropriate market--if one exists at all.

I still think it could be a useful component of LiveCode. In one iteration of the code, it can be used to move any RR control around the screen with FORWARD 10, LEFT 45, etc. See "Control Turtles" on the above web site.

Unfortunately I am out of touch with this market now and so have nothing for you about current applications, if any. Trouble is perception. It is perceived as a tool for children, a perception quickly dispelled in Turtle Geometry by Abelson and diSessa. The last chapter is titled: Curved Geometry and General Relativity. 

Jim Hurley

> 
> Message: 18
> Date: Mon, 17 Oct 2011 07:02:16 -0700 (PDT)
> From: Alejandro Tejada <capellan2000 at gmail.com>
> To: use-revolution at lists.runrev.com
> Subject: Re: New rendering testing
> Message-ID: <1318860136941-3912148.post at n4.nabble.com>
> Content-Type: text/plain; charset=us-ascii
> 
> Great work, Jim! :-D
> 
> After running these demos, finally I understand how
> useful could be for young minds, to use and learn
> Turtle Graphics.
> 
> I downloaded your book from:
> www.jamesphurley.com/jhurleyFolder/TurtlePhysics%20Text.doc
> and noticed that when I open the file
> in Open Office or WordPad, some characters are
> replaced by the question mark:
> 
> 3. Functions: direction(?,?) and distance(?,?).
> 
> By any chance, Did you write this document in
> a Macintosh and character conversion is changing
> the original text?
> 
> If possible, I would like that you point me to some
> studies that details the learning experience (for teachers
> and students) of using Turtle Graphics in the classroom.
> 
> Thanks again for sharing your groundbreaking work!
> 
> Al
>