This model illustrates the basic types of reactions that occurred at the early stages of the formation of the Universe.
The main window displays any of the four following reactions: an annihilation reaction (for protons, neutrons, and electrons) or the synthesis of helium. The lower window displays the reaction's formula. Select the process you would like to observe with the appropriate switch. Press "Run" button for the reaction to commence. Pressing "Stop" button will suspend the animation. Press "Reset" to return the model to its initial condition.
Protons and antiprotons are conveniently represented as big red and blue balls, respectively. Electrons are the small balls, whereas the neutrons are depicted as gray balls. Upon annihilation of each of the abovementioned particles, two protons emerge. They are depicted as yellow balls, and fly asunder at the speed of light.
Helium synthesis occurs in three stages. The current stage is always outlined in red.