I will give a brief history of deep learning explaining what it is, what kinds of task it should be good for and why it was largely abandoned in the 1990's. I will then describe how ideas from statistical physics were used to make deep learning work much better. Finally I will describe how deep learning is now used by Google for speech recognition and object recognition and how it may soon  be used for machine translation.

This Colloquium is jointly sponsored by Fields Institute Research in Mathematical Sciences and the Department of Physics