Re: [Phys-L] Animation of motion in a potential energy well

[Bruce Sherwood <Bruce_Sherwood@ncsu.edu>]

Not sure I understand your suggestion. I think I made a well like yours:
Starting at upper left and dragging to the right, I drew a trapping well,
then turned downward and descended way below ("-infinity") at the lower
right. When I click at an altitude corresponding to an energy that would
give a bound state, I see oscillations in the trap unless I click to the
right of the rightmost contour, in which case I see an unbound motion,
which I think is what you want, no?

In playing with the program I had found it convenient to permit clicks
anywhere to establish the energy level, and then start the particle in the
nearest region, with zero speed. But perhaps I've misunderstood your idea.
If so, perhaps we could discuss this more offline.

Glad you liked it!

I'll comment that VPython is much more mature than GlowScript, and the
computational environment for Python is far more mature than for JavaScript
(whose history until recently was mainly for making web pages dynamic). But
for me there's a charm in being able to post a URL and have colleagues try
something just by clicking the link (and react to the program), as there's
a sizable barrier to asking colleagues to install Python plus VPython and
download the application program and run it. On the other hand, not
everyone has an up-to-date browser installed, and a graphics card with
GPUs, which GlowScript's use of WebGL requires.

Here are other recent GlowScript implementations of some VPython physics
demos that you might find interesting:

http://www.glowscript.org/#/user/Bruce_Sherwood/folder/MI/program/02-NewtonGrid

http://www.glowscript.org/#/user/Bruce_Sherwood/folder/MI/program/04-SpeedOfSound

http://www.glowscript.org/#/user/Bruce_Sherwood/folder/MI/program/01-SpaceStation

http://www.glowscript.org/#/user/Bruce_Sherwood/folder/MI/program/24-Radiation3D

Bruce


On Mon, Aug 5, 2013 at 8:54 AM, Rauber, Joel <Joel.Rauber@sdstate.edu>wrote:

> Great animation!
>
> Suggested improvement:
>
> I drew a PE that had a small well to the left and then decreased to
> -infinity to the right of the well.
>
> Clicking at an altitude that could trap the particle in the well; caused
> the program to assume it was so trapped rather than in the region to the
> right where the motion would be unbounded.  So I would alter the program to
> assume that where you click (left <->right) is the initial location of the
> particle in order to take care of cases where a given total energy might be
> a particle that is localized or one that may exhibit unbound motion.
>
> Cool animation though, even as is.