The last few years have seen amazing progress in the field of artificial intelligence. AlphaGo beat the world's Go grandmasters, a feat thought impossible. The next version, AlphaZero, became the world's best chess player in four hours. Cars are driving themselves, smartphones can identify skin cancer as well as trained dermatologists, and we're on the verge of human-level universal translation. All of this is the result of not just machine learning, but actually a subset technology of machine learning called deep learning.