Introduction to the Universe (IB Option E1)
209 Seconds video showing cosmic scales:
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 is...
Rutherford Experiment (aka Geiger-Marsden)
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 of the...
Thermal Energy Transfer / Greenhouse Effect
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 subject. Before...
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.
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...
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!
What makes thermal physics interesting is that it provides...
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
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.
01 Jul What do you need to know about Free-fall, Projectile Motion, Air Resistance, and Terminal Velocity?
Free-fall: a special case of uniformly accelerated motion
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 at...