In the early 20th century, two major scientific revolutions drastically altered our understanding of nature: quantum mechanics and Einstein's theories of special and general relativity. These will be the main themes of this course, along with occasional excursions into nuclear and particle physics topics. Students will perform and analyze experiments to measure the speed of light; the mass, charge and wave nature of the electron; as well as the quantization of energy. In situations less conducive to hands-on work, data from historical experiments or computer simulations will be provided for analysis. This course picks up where a rigorous, year-long introductory physics course leaves off. Proficiency in algebra and basic physics principles will be expected.