Moo Young Han, center, with the students of his final Phy 100 Class.Students in Prof. Moo-Young Han’s Physics 100 class last semester surprised him with a customized cake to celebrate his upcoming retirement. Han, who began as an assistant professor at Duke in 1967, is retiring March 1, 2011. Han, who discovered the color charges of quarks together with Yoichiro Nambu, excels in communicating complex physics topics to students and laypeople. He has won awards for his teaching, including the Duke General Alumni Distinguished Undergraduate Teaching Award in 1972. He says he doesn’t yet have any fixed plans for retirement, although he’s hoping to travel and write more books—he’s already authored four. View photos on Flickr here.