How can we see the structure of the atom?

Rules of the Game:

The center orange disk is a massive charged body like an atomic nucleus. The twenty green dots which are located in the left side of the screen are charged particles like alpha particles. The orange body and the green particles have the same kind of charge and repel each other by Coulomb force.
First, click the start button. The
green particles start moving and are scattered by the orange body. You can change the speed of green particles by the scrollbar. If you drag the pointer near the orange body, you can change the radius of the body without changing the amount of it's charge.
Next, check the Strobo checkbox. You can see the orbit line of the
green particles. The orbit line can be erased by clicking Start or Reset button. Clicking the Reset button at any time will start the game from the beginning.

Please try to check the following points:

  1. What happens if you increase the speed of the green particles?

  2. What happens if you increase the radius of the orange body?

  3. How should we set the conditions if we want to know the radius of the orange body?

This simulation is the same situation of Rutherford's experiment.
(The calculation is done by 4th order Runge-Kutta method.)

[This applet was created by KATO Noriyoshi (norimari@mxb.mesh.ne.jp) and can also be found in http://ww2.biglobe.ne.jp/~norimari/e-sciencenori.html ]