Nuclear Physics and Radioactivity Radioactivity is spontaneous and random. The probability that an atom will decay remains constant for the entire life of the atom. If you think about it, this is really strange. How can it not matter whether a uranium atom…
Atomic Physics Rutherford Experiment (aka Geiger-Marsden) My summary Rutherford shot alpha particles at a thin film of gold foil Most of the alpha particles went right through Some had high angles of deflection He was shocked when a small number…
Thermal Energy Transfer / Greenhouse Effect Some Background IB calls this topic Thermal Energy Transfer, but really it’s about the greenhouse effect and climate change. Calling it Thermal Energy Transfer it sounds more physics-y. Climate change is of course a controversial…
The sequence of development of quantum mechanics, summed up for IB students, from me: (1) Hydrogen atoms emit a discrete spectrum of light. This is our first evidence that energy levels in the atom are quantized. What a mystery! Physicists have never seen something like this before. (2)…
a a Thermal physics provided the transition from macroscopic physics to microscopic physics, and electricity is all about electrons, so why are we backtracking now to talk about bouncing springs and wiggling strings? It’s because waves are going to be essential, ultimately, to our…
a I love physics, but I used to think this one topic, thermal physics, was boring. I had to teach it twice before I understood it well enough to see how interesting it really is! a What makes thermal physics interesting is that it provides…
a There are only four fundamental forces in physics, and in high school physics we will learn about three of them. These forces are called “fundamental” because we don’t have a deeper explanation for why they exist. The four are Gravitational Force Electric Force Strong…
4 Ways Tuition Is Done Differently at The Physics Cafe a a For secondary school and JC students, mugging the examination syllabus can sometimes feel like an uphill battle; it may be tough, but it’s definitely not impossible. Subjects like Physics and Mathematics tend to get super…
a A force is just a push or a pull There are lots of ways to push or pull: Gravity pulls objects down toward the ground. We call that force the weight of the object. A string or rope can pull on an object….
a Free-fall: a special case of uniformly accelerated motion a When you drop a hammer, it falls to the ground. While it is falling, the only force acting on it is gravity. (There’s also a little bit of air resistance, but for a hammer moving…
