Re: [sugar] [OLPC-Games] Physics -- Newtonian mechanics.. for kids!
On Thu, Jul 10, 2008 at 1:14 PM, Brian Jordan <[EMAIL PROTECTED]> wrote: > Hi friends! > > Physics is a physics playground for the XO currently being written by > myself and Alex Levenson. We hope it will be a fun tool for playing > with and learning physical concepts, and that the work of the > Physics/Elements teams can be used as a backend for making all > activities fun and interactive. Excellent. I will join your discussion. > Get it at: > http://dev.laptop.org/~bjordan/Physics-0.2.xo (click in Browse to install) > > Join the fight against everything other than Physics! > > Wiki: http://wiki.laptop.org/go/Physics > IRC: irc.freenode.net #olpc-physics > We are having a meeting at 6:30pm EST today on #sugar > (irc.freenode.net) with key XO-physicists. Join us! > Git: http://dev.laptop.org/git?p=activities/physics > > Physics currently supports: > - Creating: triangles, boxes, circles > - Drawing: polygons, "magic pen" shapes > - Grabbing objects > - Connecting objects with joints So we could simulate a pendulum or a Newton's cradle? How do you handle collisions? Any idea how many objects you can simulate and render in real time? > - Destroying objects with a fun to use red path of destruction > > Physics currently uses a default Earth-style (pointing downward) > gravity, Do you mean a Galilean constant-acceleration field for small spaces on the ground, or a Newtonian inverse-square central field including orbital space? > friction, size-based masses Can we add uniform density shown by color saturation or something like that? > and a set of colors which are > randomly picked when an object is created. We are working on > simple-to-use contextual menus for modifying and visualizing these > parameters in the activity. > > We are planning to add many other tools and toys in Physics, and > encourage suggestions (drawings/diagrams!), bug reports and code > contributions from other developers. Can you link to Measure? > Physics (by way of Elements and pyBox2D) uses the open source 2D C++ > physics engine Box2D2 as a back end, which has a lot of functionality > that we haven't implemented yet. Any thoughts about using SciPy for visualization? > Cheers, > Brian Jordan > 3D intern trapped in a 2D world > ___ > Games mailing list > [EMAIL PROTECTED] > http://lists.laptop.org/listinfo/games > -- Edward Cherlin End Poverty at a Profit by teaching children business http://www.EarthTreasury.org/ "The best way to predict the future is to invent it."--Alan Kay ___ Sugar mailing list Sugar@lists.laptop.org http://lists.laptop.org/listinfo/sugar
Re: [sugar] [OLPC-Games] Physics -- Newtonian mechanics.. for kids!
> So we could simulate a pendulum or a Newton's cradle? How do you > handle collisions? A pendulum for sure, but my version of three pendulums putting together doesn't show the expected behavior. The elasticity isn't right for it, it seems. -- Yoshiki ___ Sugar mailing list Sugar@lists.laptop.org http://lists.laptop.org/listinfo/sugar
Re: [sugar] [OLPC-Games] Physics -- Newtonian mechanics.. for kids!
On Thu, Jul 10, 2008 at 4:20 PM, Yoshiki Ohshima <[EMAIL PROTECTED]> wrote: >> So we could simulate a pendulum or a Newton's cradle? How do you >> handle collisions? > > A pendulum for sure, but my version of three pendulums putting > together doesn't show the expected behavior. The elasticity isn't > right for it, it seems. What does it do? Can you get it to tell you what values of momentum and energy are passed through from balls 1-->2-->3? I once used a 5-ball Newton's cradle to do a rough simulation of particle-mediated forces. Have you tried two pendula hanging from a horizontal string? Do you get the expected transfer of energy back and forth? > -- Yoshiki > ___ > Games mailing list > [EMAIL PROTECTED] > http://lists.laptop.org/listinfo/games > -- Edward Cherlin End Poverty at a Profit by teaching children business http://www.EarthTreasury.org/ "The best way to predict the future is to invent it."--Alan Kay ___ Sugar mailing list Sugar@lists.laptop.org http://lists.laptop.org/listinfo/sugar
Re: [sugar] [OLPC-Games] Physics -- Newtonian mechanics.. for kids!
Hi Yoshiki, These are great! I've added them to http://wiki.laptop.org/go/Physics_(activity) . Feel free to add more yourself via the upload mechanism: http://wiki.laptop.org/go/Special:Upload ! A priority is XML-format scene saving, so we can share great scenes like yours and those that will be made in the future. Physics is not "ready for deployment" until scenes can be saved and shared. [...] >> >> So we could simulate a pendulum or a Newton's cradle? How do you >> >> handle collisions? >> > >> > A pendulum for sure, but my version of three pendulums putting >> > together doesn't show the expected behavior. The elasticity isn't >> > right for it, it seems. Yoshiki, Edward -- Physics is currently contstrained by capabilities of the open source Box2D physics library. Any added engine capabilities should be added upstream to their project. See http://www.box2d.org , and there is a thriving development community (and the project founder/main coder responds to forum questions) http://www.box2d.org/forum/ Box2D Manual - http://www.box2d.org/manual.html - covers (most of) the capabilities of Box2D Erin Catto's Box2D GDC 2005, 2006, 2007, 2008 slides: http://www.gphysics.com/downloads For visualizing concrete possibilities (i.e., easy-to-access projects using Box2D or ports of Box2D): http://box2dflash.sourceforge.net/ - Actionscript 3 Box2D I tried this on the XO with the latest joyride in gnash... it wouldn't load. Will somebody please try with Flash? http://jbox2d.org/ - Java box2d... made by my brother :) No chance of working on the XO any time soon. http://box2d-js.sourceforge.net/index2.html - Javascript Box2D - actually has the 5-ball pendulum you describe, in addition to a cool motorjoint-based ball-paddling/juggling device I tested JS on the XO with the latest joyride -- it ran reasonably with two objects, unreasonably slow with three. I will be adding contextual menus (time-based... see Paint for an example) to the tool selections so you can change friction, elasticity (Box2D: restitution), mass (Box2D: density), color, etc of each element before (and maybe eventually after) adding. These are all supported in Box2D. >> >> What does it do? Can you get it to tell you what values of momentum >> and energy are passed through from balls 1-->2-->3? > See again the Box2D manual, MANY things are possible. I think, interestingly, once we add diagnostic information (visual--using colors and force-lines, auditory--using force-variable volume sound effects, and graph-able data graphing or storage) to Physics, many more opportunities for self directed learning arise. I appreciate very much any ideas (or code) that solves the difficult challenge of displaying and letting kids play with this data they are generating just by their use of Box2D. I am glad others understand the implications this amazing open source engine will have on learning Physics. :) http://wiki.laptop.org/go/Physics_meetings/July_10%2C_2008 We had a (disorganized, last-minute) meeting yesterday to discuss next steps for the OLPC Physics community. We are looking into making movement drawing faster on the XO (as it seems, surprisingly, to be our limiting Physics performance factor), a common format between our collective physics playgrounds, and involving developers of other (many closed source) physics engines to consider helping us and, in some cases, Box2D. http://wiki.laptop.org/go/User:Bjordan/Ideas/Teacher_involvement#Physics Cheers, Brian Ahh, the importance of having a working demo... :) > Heh, of course you can try by yourself. But if you put a circle on > the floor (stand still), and make another hit from the side, the > momentum is shared by these two circles and both of them move together > at the same speed. > >> Have you tried two pendula hanging from a horizontal string? Do you >> get the expected transfer of energy back and forth? > > Yes, but no. I'm not sure what you mean by a horizontal string, but > the string I made is not flexible enough to make it happen. > > Speaking of examples, the screenshots at > http://wiki.laptop.org/go/Physics_(activity) aren't exactly something > I found "physics-y"; these are more like story telling in picture > books. I made some examples (two pendula and a mesh, I did an arch > but it is gone). These might catch more attention from teachers and > educators. > > -- Yoshiki > > ___ > Sugar mailing list > Sugar@lists.laptop.org > http://lists.laptop.org/listinfo/sugar > > ___ Sugar mailing list Sugar@lists.laptop.org http://lists.laptop.org/listinfo/sugar
Re: [sugar] [OLPC-Games] Physics -- Newtonian mechanics.. for kids!
Thank you, Brian, Are you now commuting to 1CC? If so, we (all Etoys team including Takashi, who did ODECo ODE binding for Etoys) are visiting Cambridge the week after next, so we may have a chance to talk about it (possibly on Wednesday. -- Yoshiki ___ Sugar mailing list Sugar@lists.laptop.org http://lists.laptop.org/listinfo/sugar
Re: [sugar] [OLPC-Games] Physics -- Newtonian mechanics.. for kids!
On Sat, Jul 12, 2008 at 4:21 PM, Yoshiki Ohshima <[EMAIL PROTECTED]> wrote: > At Thu, 10 Jul 2008 16:58:32 -0700, > Edward Cherlin wrote: >> >> On Thu, Jul 10, 2008 at 4:20 PM, Yoshiki Ohshima <[EMAIL PROTECTED]> wrote: >> >> So we could simulate a pendulum or a Newton's cradle? How do you >> >> handle collisions? >> > >> > A pendulum for sure, but my version of three pendulums putting >> > together doesn't show the expected behavior. The elasticity isn't >> > right for it, it seems. >> >> What does it do? Can you get it to tell you what values of momentum >> and energy are passed through from balls 1-->2-->3? > > Heh, of course you can try by yourself. But if you put a circle on > the floor (stand still), and make another hit from the side, the > momentum is shared by these two circles and both of them move together > at the same speed. > >> Have you tried two pendula hanging from a horizontal string? Do you >> get the expected transfer of energy back and forth? > > Yes, but no. I'm not sure what you mean by a horizontal string, but > the string I made is not flexible enough to make it happen. > > Speaking of examples, the screenshots at > http://wiki.laptop.org/go/Physics_(activity) aren't exactly something > I found "physics-y"; these are more like story telling in picture > books. I made some examples (two pendula and a mesh, I did an arch > but it is gone). These might catch more attention from teachers and > educators. Yoshiki, This gave me an idea... Just after adding motors to the most recent version of Physics (too fun), I took a BULB-exposure shot of Physics in motion on my camera. Here is the result: http://wiki.laptop.org/go/Image:Housegolf.jpg Neat! Thanks, Brian > > -- Yoshiki > > ___ > Sugar mailing list > Sugar@lists.laptop.org > http://lists.laptop.org/listinfo/sugar > > ___ Sugar mailing list Sugar@lists.laptop.org http://lists.laptop.org/listinfo/sugar
