This site has some samples about gravity. http://www.geometrian.com/Tutorials.php
cheers. On Wed, Dec 2, 2009 at 10:09 PM, Bill Coderre <[email protected]> wrote: > On Nov 30, 2009, at 11:13 AM, Ian Mallett wrote: > > g = -9.8m*s^-2. > > > If you want to learn about gravity, watch this video: > http://video.google.com/videoplay?docid=-9055536763288165825 -- but be > careful or you might get inspired. > > I say that because this video is an instance of The Canonical Alan Kay > Lecture. Indulge me a few paragraphs to explain what that means. > > Alan Kay is a famous computer scientist, mostly known for three things: > 1) His witty sayings, such as, "The best way to predict the future is to > invent it," and "A good point of view is worth eighty IQ points;" > 2) Actually "Inventing the Future;" and > 3) Inspiring other programmers to invent the future. > > In 1969, Alan had a vision: kids learning to "think about thinking," using > what he called a "DynaBook" -- which we now call a laptop computer. Since > his vision was a long way off, he got a group together at Xerox PARC, and > they developed a "working prototype" that was the size of a mini-fridge, but > otherwise fit the bill. Steve Jobs brought his own gang to see a demo of > that, and they were inspired to make Macintosh. > > Now we have laptops and GUIs, and Alan and conspirators have been inventing > new programming systems with Squeak (a newer version of Smalltalk) as their > "assembly language core." Etoys is one of them, and if you haven't tried it, > you should.[1] > > Alan inspires other programmers by showing (formerly-rare) demo footage of > groundbreaking computer systems, such as Ivan Sutherland's Sketchpad from > 1963 [2], and Doug Engelbart's "Mother of All Demos" from 1968.[3] > > When I was at the MIT Media Lab, as a student of Alan's, I saw this > Canonical Lecture a lot -- even gave it myself a few times. I still find it > awe-inspiring and humbling. > > In this video, you'll see some of Alan's inspirations, and some results of > using Etoys in schools, including kids learning about gravity by simulating > the motion of a ball falling -- in the video from about 27 minutes to about > 33 minutes. > > Sure, Doug Engelbart and Ivan Sutherland were geniuses, and Alan's no > slouch himself, but the kids in Alan's demos are not. They've just found a > good point of view, and a good method of expression. It's our job, as > programmers, to create better methods of expression. We owe it to the > future. > > I don't know if Alan has commented on Python,[4] but I think he'd approve > of it, before pointing out that "the real computer revolution hasn't > happened yet." I think he'd make the point that programming language > designers only recently have gotten past the absurd and harmful goal of > making languages easy for computers to understand and execute. This is so > important I am going to set it off by itself: > > *It was only 10 years ago that people were still railing against the > notion of garbage collection because it cost as much as 15% extra RAM, and > 5% of your CPU's power. [5] > * > Now we're seeing lots of new programming languages, and many of them are > starting to have slightly more sophistication than object-oriented > programming's "stacking blocks of granite" approach. (As Alan would say, > "But that worked great for the pyramids, and required far less heavy lifting > than most people think!") List Comprehensions, to my mind, are the next > step beyond Lisp's "map" and "filter" paradigm, which I think of as > "flint arrowheads." I hope I live to see the invention of computer > programming's "screw fasteners." > > *Man is most nearly himself when he achieves the seriousness of a child at > play*. - Heraclitus > > > > > > [1] http://www.squeakland.org/ -- you simply must download and try Etoys. > > [2] http://www.youtube.com/watch?v=USyoT_Ha_bA -- Sketchpad ran on a > computer built out of individual transistors, with a "CPU Speed" of less > than 200 kHz (my Mac has 8 cores running at 2.8 GHz, so about 112,000 times > as fast), and 64K of 36-bit words (and my Mac has about 30,000 times as > much). > > [3] http://video.google.com/videoplay?docid=-8734787622017763097# > -- Engelbart's demo is astounding because it was the first demonstration of > "tele-computing" (the computers were over 30 miles away, and this was a year > before the first test demo of "Internet" technology, and almost 30 years > before computers had built-in ethernet ports). It also was the first demo of > his "mouse" computer interface. > > [4] Alan gave a talk to EuroPython in 2006, but I haven't had a chance to > watch it yet. It's here: http://blip.tv/file/51211 > > [5] And even then, your computer was idle 98% of the time. I am amused > because the entire Macintosh Common Lisp I cut my teeth on fit could easily > run in 4 MB of RAM. One day I was wondering why it was GC'ing so much, > and it turned out that the memory had gone bad -- the entire system had to > run in about 128KB. > -- Leônidas S. Barbosa (Kirotawa) [DesenvolvedorWeb/CEFET/RN] [Ciências da Computação/UFRN] [pós-graduando em Inteligência Computacional/Processamento Gráfico /UFRN [Estudante de japonês nível 8 - Japanese Student] [Desenvolvedor em python, PyGame] blog: corecode.wordpress.com/ "Mais sábio é aquele que sabe que não sabe" (Sócrates) 日本語の学生です。 コンピュータサイエンスの学位.
