Challenge on conservation of angular momentum

In order to fix some important concepts of Fundamental Physics, either because they are not usually discussed in depth in theoretical classes and much less at laboratories, or because they are not sufficiently developed in textbooks, it is more effective not to tackle them directly, but to propose a mental or practical experiment to attract the student’s attention by questioning their beliefs about it (erroneous preconceptions). We propose a new example about the conservation of angular momentum of a system of material points in this way previously explained.

Testing Quantum Mechanics with an Ultra-Cold Particle Trap

It is possible to empirically discriminate between the predictions of orthodox (i.e., Copenhagen) quantum theory and the de Broglie−Bohm theory of quantum mechanics. A practical experiment is proposed in which a single, laser-cooled ion inside an ultra-cold particle trap is either found to be near the trap’s walls or not. Detections of the former kind would support the prediction of orthodox quantum theory and of the latter kind would support the de Broglie−Bohm theory. The outcome of this experiment would show which theory gives the more correct description and, consequently, would have far-reaching implications for our understanding of quantum mechanics.

GUI ベースの web 実験作成ツール(lab.js)の紹介と実践

lab.js Builder is free and open-source software that makes it easy to build experiments and surveys for both online and in-laboratory data collection. By using its visual interface, stimuli can be designed and integrated into experiments and surveys without programming, though it can be also customized using HTML, CSS, and JavaScript code. This software would be beneficial for many students and scientists to build and run their experiments and surveys under the situations of homeschooling and remote working. In this tutorial article, we introduce the functions of lab.js Builder and easy-to-use method for it, and also demonstrate the method of building and conducting the practical experiment at the class of the university.