The objective of this post is to: (i) generate a discussion of whether results of the double-slit experiment address solely the nature of matter, or do the results also address the nature of probability; and (ii) to determine if there have been any comparably structured experiments outside of the realm of quantum mechanics; and if so, their results. Background / My understanding: The famous double-slit experiment applied in Quantum Mechanics was designed to answer the question of whether electrons and photons (and other components of matter) are comprised of particles or waves. The counter-intuitive result is that when no observation takes place of which “slit” electrons or photons pass through, then they act like waves, as evidenced by an interference pattern that results from waves travelling through, and meeting on the other side of, the two slits. On the other hand, when measurements enable the observer to determine which slit an electron or photon passes through, then they act like particles, with no interference pattern. Among the explanations in the latter case is that when observation takes place, all other wave function probabilities, aside from the observed result, collapse. The debate on the significance of this result in determining the nature of matter on the quantum scale has raged for decades, even delving into the role of human consciousness in influencing the outcome. What seems absent from the debate, as far as I know, is the significance of the result in shedding light on the nature of probability itself, rather than on the nature of matter. So here are my questions. Have there been any statistical studies outside of the realm of quantum mechanics that would attempt to mimic the double slit experiment? If so, what have been the results? I could envision a test structured with two sets of trials, as follows: A large number of trials in which a single, ordinarily marked die is rolled 600 times, with a calculation of the distribution of outcomes of all trials that reflects: The number of times “1” comes up in each trial; The number of times “6” comes up in each trial; Then perform an equal number of trials, except using a die on which there are no numbers, and on which two sides are painted red, and the other four sides are painted blue, and calculate the distribution outcomes of all trials that reflects the number of times that “red” comes up in each trial. Would there be any statistical basis on which to expect that the distribution of outcomes on the second trial would be anything other than the sum of distributions for “1” and “6” on the first trial? If there is any difference, would it correspond to wave-like interference patterns? Is the structure of this test sound? Does this test structure properly mimic the double-slit experiment? Following is a slight modification, intended to be equivalent to “narrowing” of the slits, which I understand to be important in the double-slit experiment. Perform a large number of trials in which a single, ordinarily marked die is rolled 600 times, and calculate the number of trials for which “1” comes up between 99 and 101 times, as well as the number of trials for which “6” comes up between 99 and 101 times: Then perform an equal number of trials, except using a die on which there are no numbers, and on which two sides are painted red, and the other four sides are painted blue, and calculate the number of trials for which “red” comes up between 198 and 202 times. Would there be any statistical basis on which to anticipate that the number of trials for which “red” comes up between 198 and 202 times, would be any different than the sum of the number of trials for which “1” and “6” come up between 99 and 101 times? Have any tests like this been performed? What would be the relevance of these tests to the double-slit experiment? To me, such an outcome would suggest that the double-slit experiment sheds less light on the nature of matter than it does on the nature of probability. All comments welcome. Thanks!