Two institutes for secondary school physics teachers will be conducted at Westminster College, one in the summer of 1990, the second a year later. At each of these three-week workshops, 20 teachers will learn about topics in modern physics, take part in hands-on activities involving modern physics, and develop teaching units on modern physics concepts. The content will center on Particle Physics, as understood in terms of the Standard Model, and its relation to everyday events as well as its implications for cosmology. The Standard Model describes the structure of all matter in terms of a few fundamental particles (quarks and leptons). Opportunities will be provided to review basic concepts in preparation for this study. Participants will come from the region comprised of western and central Pennsylvania, western New York, eastern Ohio, northern West Virginia, and western Maryland. Selection will be based on the applicants' interest in modern physics and commitment to incorporate modern physics topics in their courses. Applications from minorities and women are encouraged. Participants will receive a $900 stipend, room and board, and a selection of modern physics teaching materials. They also will earn three semester hours of graduate credit. Institute activities will include lectures and discussions, review sessions, films and video tapes, and hands-on activities involving laboratory and demonstration apparatus, computer simulations and modern physics "games". Several new modern physics teaching aids will be introduced including "The Fundamental Particles and Interactions Wall Chart" and the notebook, "Topics in Teaching Modern Physics Teacher Resource Materials". There will be field trips to the Cornell Electron Storage Ring accelerator at Cornell and to the Proton Decay Experiment near Cleveland. Participants will develop two teaching units on modern physics for incorporation into their curriculum and will share experiences and report on progress at local conferences to be held in the Spring of 1991 and Spring 1992. Cost sharing in an amount of $55,724 equals 36% of the NSF award.