1. Random phenomena

Various examples of such phenomena can be given:

• coin toss ;

• dice-throwing game ;

• life of a light bulb ;

• bus transit time ;

• a drunkard's walk: one step forward, one step back... ;

• trajectory of a pollen dust on the water surface of a vase.

In the first two examples, the difference between the results, if the experiment is repeated, may be linked to the initial impulse imparted to the die, the roughness of the table, the vibrations of the floor... Chance is therefore merely an illustration of our ignorance of the initial conditions, since the coin or die have trajectories that are perfectly defined by classical mechanics.