The paper summarises the main differences between the process of throwing dices and the measurement process, and draws some of the consequences on the meaning and use of the probability concept in the two case.
Suppose that you are playing a dice game with a friend. You throw two sixes and you feel very happy because you know that you are going to win. You even think that it may be unnecessary for your friend to throw the dice. The probability that he will also throw two sixes is very small indeed, and in any case you are sure that he cannot obtain a better score than yours. Now he throws the dice, and here comes a big surprise – a six is face up on one of the dice, while the second one splits in two, showing two faces: one face with a six and the other face with a one.
A simple experimental setup to produce true random numbers is described. The experiment involves measuring successive times between decays of a radioactive source. We discuss two different ways of comparing these times: one that generates a string of random zeros and ones, and another that produces numbers derivable from the permutation group. It is shown that the methods used in the experiment produce the same results for any random process and can therefore be used as a test for randomness in other physical systems.