How Did You Do That?

Rock Mackie is a medical physicist who invented a safer type of therapeutic radiation, called tomotherapy, that delivers less radiation with just as much effectiveness. It has saved many lives. During a 25-year tenure as a University of Wisconsin-Madison professor, Mackie taught radiation physics and dosimetry, wrote 185 peer-reviewed publications, secured more than 50 patents and supervised 42 Ph.D. students. But he also successfully made the difficult transition from academia to business. Mackie has started six companies, including most recently Linectra, a Madison company he co-founded in 2019 that is developing a metal 3D printer for manufacturing uses. In all of his startup endeavors, he has mentored and nurtured other up-and-coming entrepreneurs. His most successful startup, TomoTherapy Inc., raised $185 million in a 2007 initial public offering and sold for $277 million to Accuray Inc. in 2011. Mackie says he's never been driven by the desire to make money; he's always been part