What jobs other than a university professor does a 4 year physics degree have to offer?

You have to have a PhD to be a professor

You cannot become a professor with a 4-year (bachelors) degree in physics.  You need at least a masters degree (6 years) to teach at a 2-year college (community, technical) and you need a PhD (8-12 years) to teach at a 4-year college or university.  With a bachelors in physics, you could probably teach high school (although some states require a masters to teach high school), you could work for a power company, maybe get a job as a data analyst for NASA or a national lab, work for many research and development companies (Sony, Apple, IBM, etc), or many other jobs.