Syllabus

Download a full course syllabus here.

Course Description

Quantum mechanics was discovered in the context of atomic physics, but unlike many of the named classes in our curriculum it is not a subfield of physics in the same way that atomic physics or optics or particle physics are. Instead, it encompasses (almost) all the known subfields of physics and provides a new understanding of two of the pillars of physics: what it means to describe a physical system (a system's configuration, or more formally its state) and what is possible when you measure a system (its measurement outcomes). The exception to this statement is gravity; many researchers, myself included, are trying to fathom how gravity fits in. Perhaps gravity is even pointing us towards a need for reimagining quantum mechanics?

I quite like Scott Aaronson's analogy that quantum mechanics is like a computer's operating system (OS). You can run optics or atomic physics as software on this OS, but fundamentally, it determines what is possible. It determines what you can compute and measure. It is a new framework. Think about what it was like when you learned Newtonian mechanics for the first time. Forces are by no means intuitive and they don't help you think about every physical scenario or solve every problem. Nonetheless, the Newtonian framework provides an irreplaceable perspective on how to predict and understand physical motions. Quantum mechanics revolutionizes this understanding and framework.

The analogy with an operating system is also useful in thinking about the sort of mental shift you need to make as a student of quantum mechanics. If you pick up a friend's computer running an unfamiliar OS you will often find it challenging to do simple operations. Despite these difficulties you know quite well what a computer does; similarly, you know quite well what quantum mechanics does—it provides a quantitative framework for predicting the outcomes of measurements—so don't lose track of this picture as you are familiarizing yourself with its operational procedures.

Many people bring a great attitude to learning a new computer OS; they simply muck around with it until they get the hang of it. When they screw up, they simply say "oops" and try again. I strongly encourage you to bring this mindset to learning quantum. After all, it's a new OS, you should expect to turn many wrong nobs and totally misinterpret some relationships until you are more familiar with it. Don't believe the hype—quantum mechanics is not overly difficult, just unfamiliar and surprising at times.