Nucleon structure and the proton radius from lattice QCD

The measurement of the proton charge radius based on spectroscopy of muonic hydrogen significantly disagrees with measurements from ordinary hydrogen spectroscopy and electron-proton scattering; this is known as the proton radius puzzle. An ab initio calculation based on lattice QCD could help to further our understanding of this puzzle. In this talk, I will give an overview of the status of lattice QCD calculations of nucleon structure and present some progress toward a reliable calculation of the proton radius. I will also discuss what we have learned about the role that strange quarks play in nucleons.