Physics for Education | Radioactive Dice

Simulation documentation

A computer simulation of the “radioactive dice” classroom experiment, which models radioactive decay. Microsoft's pseudorandom number generator is used to generate random numbers in lieu of dice.

The four user-controlled options in the simulation are:

• Probability of decay per roll (between 0 and 1)
  e.g. 0.16667 is equivalent to rolling 6-sided dice; 0.25 is equivalent to rolling 4-sided dice; 0.5 is equivalent to tossing coins.
• Initial number of “dice nuclei” to be rolled (from 1 to 10,000,000)
• Unit of time to be represented by each roll of the dice (e.g. second, hour, day, etc.)
• Number of times that the “dice nuclei” are to be rolled (from 1 to 1,000)
  This is equivalent to the number of units of time that the simulation is to represent.

The decay constant and half-life are automatically calculated from the chosen probability and time unit. These two values can be independently viewed in a range of units (chosen from the drop-down boxes next to each number).

When the “Run Simulation” button is pressed, a light blue curve is drawn, which is the theoretical prediction of the decay calculated using the Rutherford-Soddy exponential decay equation. The simulation then proceeds to roll the “dice”. A series of black vertical lines are plotted, representing the number of dice remaining after each roll. These results are random (really pseudo-random) and change each time the simulation is run. The more dice rolled, the closer the results match the theoretical prediction.