Ready to level up your working knowledge of quantum mechanics? Check out these four TED-Ed Lessons written by Chad Orzel, Associate Professor in the Department of Physics and Astronomy at Union College and author of How to Teach Quantum Physics to Your Dog.

1. Particles and waves: The central mystery of quantum mechanics

One of the most amazing facts in physics is that everything in the universe, from light to electrons to atoms, behaves like both a particle and a wave at the same time. But how did physicists arrive at this mind-boggling conclusion? In this lesson, Orzel recounts the string of scientists who built on each other’s discoveries to arrive at this ‘central mystery’ of quantum mechanics.

2. Schrödinger’s cat: A thought experiment in quantum mechanics

Austrian physicist Erwin Schrödinger, one of the founders of quantum mechanics, posed this famous question: If you put a cat in a sealed box with a device that has a 50% chance of killing the cat in the next hour, what will be the state of the cat when that time is up? Orzel investigates this thought experiment.

3. Einstein’s brilliant mistake: Entangled states

When you think about Einstein and physics, E=mc^2 is probably the first thing that comes to mind. But one of his greatest contributions to the field actually came in the form of an odd philosophical footnote in a 1935 paper he co-wrote — which ended up being wrong. Here, Orzel details Einstein’s “EPR” paper and its insights on the strange phenomena of entangled states.

4. What is the Heisenberg Uncertainty Principle?

The Heisenberg Uncertainty Principle states that you can never simultaneously know the exact position and the exact speed of an object. Why not? Because everything in the universe behaves like both a particle and a wave at the same time. In his final lesson, Orzel navigates this complex concept of quantum physics.