Why Quantum Mechanics?

Chem 3240 · Lecture 1.1

Davit Potoyan

What is quantum mechanics?

The fundamental theory of nature, governing atoms, molecules, and subatomic particles.

  • A complete description of physical reality
  • Has never failed an experimental test since its discovery
  • Verified to an astonishing degree of accuracy

Beware: quantum mechanics is weird 🤯

“I think I can safely say that nobody understands quantum mechanics.”

Richard Feynman

Be prepared to let go of the idea that “things make sense.” We can still master the logic of QM and apply it everywhere.

QM is not “just another theory”

In the hierarchy biology → chemistry → physics → math, quantum mechanics sits in a unique spot:

It is like the operating system on which other theories run as “apps.”

Translating a classical theory into this OS is what physicists call quantization.

Scott Aaronson, Quantum Computing Since Democritus (2013)

Where is quantum mechanics applied?

  • Chemistry & materials
  • Lasers, LEDs, semiconductors
  • MRI & medical imaging
  • Quantum computing

Takeaway

If you feel you don’t fully understand QM, you’re in good company, with everyone else. The goal is to master its logic, not its intuition.