This course is a one-semester introduction to current research topics in physics, organized around six 'Big Questions' in physics, including: what are the ultimate laws of nature, how does complex structure arise, and how can physics benefit society? This course is more quantitative than 131S and is designed for prospective physics majors as well as those interested in deeper understanding of the physical world. Prerequisites: Precalculus and at least one quantitative science course at the high school level, such as chemistry or physics.