Physics Forums Insights
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Scientific physics forums for professionals and students to discuss serious issues and topics regarding physics in theory, practice, study and reality. Students can also find help for homework and career perspectives
Physics Forums Insights
2w ago
The concept of quantum superposition (or superposition for short) is very counterintuitive, as Schr##\ddot{\text{o}}##dinger noted in 1935 writing [1], “One can even set up quite ridiculous cases.” To make his point, he assumed a cat was closed out of sight in a box with a radioactive material that would decay with 50% probability within an ..read more
Physics Forums Insights
2w ago
The slinky drop is a rather simple experiment. In its most basic form, it requires only a popular toy for children, a stable hand, and a keen eye. For a better view, using a modern smart phone to capture a video of the experiment also helps to capture the falling slinky. Apart from the commonly ..read more
Physics Forums Insights
2M ago
Introduction The figure on the right shows a “double-double” Atwood machine with three ideal pulleys and four masses. All pulleys are released from rest simultaneously. Which of the choices below describes the angular motion of the top pulley P after some time has elapsed and why? It rotates clockwise with increasing angular speed. It rotates ..read more
Physics Forums Insights
3M ago
A division by zero is primarily an algebraic question. The reasoning therefore follows the indirect pattern of most algebraic proofs: What if it was allowed? Then we would get a contradiction, and a contradiction is the greatest enemy of mathematical rigor. Many students tried to find a way to divide by zero once in their ..read more
Physics Forums Insights
4M ago
Introduction This elaborates some of the claims in my insights article on digital audio. The Sinc Function The first link in my insights article has a section on filters, but I will detail the most critical case. The bit depth is assumed to be so large for all practical purposes that it is infinite, and ..read more
Physics Forums Insights
4M ago
Introduction First, we need some background in Digital Signals. This can be mathematically quite advanced, but since I would like this article to be accessible to as wide an audience as possible, here is a link that explains what is needed (not even Calculus is required): https://brianmcfee.net/dstbook-site/content/intro.html An important point not emphasised in the above ..read more
Physics Forums Insights
5M ago
Introduction Series play a decisive role in many branches of mathematics. They accompanied mathematical developments from Zeno of Elea (##5##-th century BC) and Archimedes of Syracuse (##3##-th century BC), to the fundamental building blocks of calculus from the ##17##-th century on, up to modern Lie theory which is crucial for our understanding of quantum theory ..read more
Physics Forums Insights
6M ago
Abstract I remember that I had some difficulties moving from school mathematics to university mathematics. From what I read on PF through the years, I think I’m not the only one who struggled at that point. We mainly learned algorithms at school, i.e. how things are calculated. At university, I soon met a quantity called ..read more
Physics Forums Insights
8M ago
Introduction In a previous article on measuring battery internal resistance, a simple technique for low-resistance measurement was outlined. In this article, the technique has been modified and expanded somewhat although the basic method remains the same. It is about as simple as it gets – one passes current through a reference resistor in series with ..read more
Physics Forums Insights
8M ago
Abstract “Mathematics is the native language of nature.” is a phrase that is often used when it comes to explaining why mathematics is all around in natural sciences, especially in physics. What does that mean? A closer look shows us that it primarily means that we describe nature by differential equations, a lot of differential ..read more