Trending Articles in Physics
Recent
Schrödinger’s Cat and the Qbit
/27 Comments/in Physics Articles/by Mark StuckeyThe 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…
The Slinky Drop Experiment Analysed
/1 Comment/in Physics Articles/by OrodruinThe 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…
How to Solve a Multi-Atwood Machine Assembly
/0 Comments/in Physics Tutorials/by kurumanIntroduction 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…
Epsilontic – Limits and Continuity
/1 Comment/in Physics Articles/by fresh_42Abstract 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…
The Poor Man’s Milli-Ohm Meter
/0 Comments/in Physics Articles/by Neil ParkerIntroduction 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…
Differential Equation Systems and Nature
/12 Comments/in Bio/Chem Articles, Mathematics Articles, Physics Articles/by fresh_42Abstract “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…
How to Apply Newton’s Second Law to Variable Mass Systems
/0 Comments/in Physics Tutorials/by kurumanIntroduction The applicability of Newton’s second law in the oft-quoted “general form” $$\begin{align}\frac{d\mathbf{P}}{dt}=\mathbf{F}_{\text{ext}}\end{align}$$ was an issue in a recent thread (see post #4) in cases of systems with variable mass. The following example illustrates the kind of confusion that could arise from the (mis)application of Equation (1): A rocket is hovering in place above ground…
How Quantum Information Theory Solves “the only mystery” of Quantum Mechanics
/0 Comments/in Physics Articles/by Mark StuckeyIn Chapter 37 of “The Feynman Lectures on Physics Volume 1,” Richard Feynman famously wrote that the mystery of wave-particle duality in the double-slit experiment is: a phenomenon which is impossible, absolutely impossible to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only…
Opinion: When Pro Scientists Explain Using Pop Science
/19 Comments/in Education Articles, Physics Articles/by fresh_42Abstract There is so much to say about the many endeavors by professional scientists to explain to us the world. The list is long: Carl Sagan, Harald Lesch, Neil deGrasse Tyson, Sabine Hossenfelder, Michio Kaku, and I even saw Roger Penrose and Steven Hawking on tv. The list is – of course – considerably longer…