In a dark suitcase set-up photons pass a double slit one by one and yet create interference. How can we use this in an effective lesson on wave - particle duality?
Abstract In the past there has been great faith in the power of laboratory activities and teacher demonstrations to enhance the learning of physics concepts. However, reviews of the effectiveness turned out to be disappointing [1-3] and have shown that lab activities and demonstrations need to be carefully designed and embedded in lessons to realize cognitive benefits [4]. Nevertheless, for secondary school quantum physics we developed a portable double slit demonstration mounted in a suitcase in which photons pass the slits approximately one by one and yet together produce an interference pattern. Based on experiences in 5 schools, we carefully designed the educational aspects of the demonstration and investigated its longterm learning effects through a written test of 68 students after 4 weeks and retention interviews after 4 months (10 interviews) and after 9 months (5 interviews). Students did remember the setup and results of the demonstration quite well. They were quite aware of the unexpected and strange wave-particle behavior of quantum particles in the demonstration including the effect of measurement or observation on the outcomes. However, half of them still had trouble defining duality in their own words and most of them did not remember de Broglie particle waves and how that related to the double slit experiment.
We report observations of Cross-Double-Slit Experiment and Which-Path-Cross-Double-Slit experiment. Cross-Double-Slit apparatus contains two double-slit, where first double-slit is perpendicular to second double-slit. The first double-slit and the second double-slit generate not only their own interference pattern perpendicular to each other, but also generate “Cross-interference-patterns”. When we do which-way experiment with one of two double-slit, say first double-slit, then its interference pattern disappeared, i.e., photons behave as particles; but the second double-slit’s interference pattern and the cross-interference-pattern still exist; which implies an significant phenomenon that in the same experiment, photons behave as both wave and particle, which is first time caught on film. Thus we suggest to re-study wave-particle duality, which is the basic mystery of quantum mechanics. We postulate that the particle nature of photons is intrinsic; while the wave-like of photons is manifest-behavior.
Abstract: Many problems exist in the Double Slit Experiment when you consider that the elements in the test are moving as waves. Outside of the pattern resembling peeks and troughs that overlap each other; there is no real scientific explanation on how this is taking place. In a more accurate and classical way, can we explain how the dark and light areas of the interference pattern are being made? Why is an Interference pattern being made when particles are being sent through the exercise one at a time? And how is it that through observation the Interference pattern collapses in on itself. Waves add more questions than they do answers, a very typical outcome of an incorrect solution. Maybe the unanswered questions left behind by the wave theory is a confirmation of its inaccuracy and not the mystique of its results. Rather than double down on the wave theory with time traveling particles, elements of duality, and the Copenhagen Interpretation; l reconsidered that elements tested in the double slit experiment behave as particles. But this time, I weighed the thought that these bits of matter are much smaller than previously thought. This new logic allowed particles with straight trajectories to interact with the edge of materials used in the double slit wall in a very detailed way. This created a storm of new ways to look at what is really taking place in the test; revealing the competence of the detectors utilized and the capacity of the Nonlinear Optical Crystal. Everything solved from just one idea, that quantum move as particles but on a much smaller scale. This is the enigma of the Double Slit Experiment.