Message: 17 Date: Sat, 2 Apr 2005 08:45:25 -0800 (PST) From: Alejandro Tejada <[EMAIL PROTECTED]> Subject: Re: ANN Nine Ball with Spin (English) To: [email protected] Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset=us-ascii
Hi Jim,
Your have make better an already excellent stack! Greetings!!! :-)
Like everyone, i have my wish list for your stack. ;-)
This is my wish list for future versions of Nine Ball:
1- An undo command to place all the balls in their previous position after a shot. In real life this an impossible feature, but in the computer this is possible, by storing the loc of all the balls before a shot.
2- A floating console (or substack) that shows the numerical quantities of the variables that player is applying in a shot... this does not sound like much fun, but permits (with the undo option) to learn eventually how works forces in movement.
3- A pool Genie. This is a feature that suggest a shot to the player, with previews of outcomes of diverses shots. Yes, i know what you are thinking but this is not cheating. Consider this like a player in the computer...
Al,
Whew! Great ideas, but not right now.
Actually, I stumbled into Nine Ball by accident--isn't that always the way. I had set out to do a Statistical Mechanics simulation, an illustration of the Second law of Thermodynamics, demonstrating that a thermodynamic system assumes the most disordered state compatible with the constraints.
It is easy to see this in physical space. Set a number of balls moving in a frictionless environment and they become randomly distributed in space. But the randomization takes place not only in geometric space but in velocity space as well. There was a popular misconception that if and when the universe began to contract that time would begin to move backward. Stephen Hawkings was one of the early advocates for this position. You can find a discussion of this in his "Short History of Time"
The thing that Hawkings neglected was that a contracting universe is not becoming ordered, the entropy is not decreasing. One has to consider not just the decrease in geometric states available in the contracting space, but also the increase in velocity states made available in the contraction--gravitational energy converted to kinetic energy. The increase in disorder associated with the velocity states exceeds the loss in position states. The total disorder increases and all is right with the second law.
So I wanted to show that if one had a large number of objects (pool balls) initially all moving with the same speed in the same direction (highly order velocities) that, if you introduced collisions, the velocities would randomize and eventually assume the Maxwell-Boltzmann distribution, i.e. a bell curve.
But, alas, Run Rev was not quite up to the task. Couldn't get enough balls to make for good statistics.
In any event, I didn't want to waste the collision routines, so I got caught up in Nine Ball.
But I am off to something else right now--using Run Rev to create a simulation contrasting global warming on Venus, Earth and Mars. (Right now I need a tool for making circular arcs--like the Run Rev pie shaped circular segments, but without the radial lines. May be a job for Turtle Graphics.)
Long winded way of saying, I'll have to pocket Nine Ball for the time being.
Jim _______________________________________________ use-revolution mailing list [email protected] http://lists.runrev.com/mailman/listinfo/use-revolution
