Geography professor John Fraser Hart, 91, has been teaching Social Sciences at the University for 48 years and retired in the Spring.The World War II veteran traveled the world studying geography and taking pictures, much of which were used as slides during his lectures. Hart’s style of teaching is considered traditional, but in a time of developing technology and hopes to attract younger scientists, his methods have phased out.

When professor Hart turned 70 in 1994, a law that required retirement at his age was repealed. Hart said after that, he and his same-age colleagues didn’t leave the school because they were no longer forced to.

“I stuck around because I could,” he said.

Last year, the average retirement age at the Twin Cities campus was 69.