Most people retire at a reasonable age. Not Harvey Picker. He turns 90 today, and he’s in Boston for some business appointments on his way home to Camden after one of his four or five trips a year to meet with associates in England, Switzerland and Germany.

Nary a word about retirement for Harvey Picker, after a career in science, business, government and education. If the name Picker sounds familiar, you may have noticed it on an X-ray film. His father started Picker X-ray (now NRC+Picker), producing air-dropped X-ray labs for the Army in World War II and the Korean War among other cutting-edge products. Harvey later led the company into such fields as cobalt treatment for cancer and ultrasound and nuclear imaging diagnostics.

He shifted gears at the age of 50, sold the business, earned a doctorate, worked briefly in the diplomatic service, taught political science at Colgate and served 11 years as dean of Columbia University’s School of International and Public Affairs, while his wife, Jean, served as a U.S. delegate to the United Nations. She died in 1990.

In another career switch in 1982, he bought Wayfarer Marine in Camden and ran and expanded the boatyard for 15 years, meanwhile frequently sailing his 45-foot ketch, Branta, He now relies on push-button trimming and furling the sails and has the assistance of a crew.

He helped organize the annual Camden Conference on International Affairs and led in a major expansion of the Camden Public Library.

One of his finest achievements came with his service on a commission to overhaul Maine’s grossly expensive workers’ compensation system. He helped devise a yardstick mechanism to bring down exorbitant insurance rates. He was one of the founders of the Maine Employers Mutual Insurance Co. (Now MEMIC), which has successfully reduced rates and, equally important, improved on-the-job safety.

Mr. Picker would like to see something similar that would reduce the cost of health care in Maine and in the rest of the United States. He regards Maine’s DirigoChoice as a good start but thinks it could be more efficiently run. He also objects to the way antibiotics and new diagnostic aids have caused medicine to focus too much on particular diseases and their treatment rather than on patients as individuals.

Not that Mr. Picker is asking for a place on some new blue ribbon commission, but he would like to see basic changes.

He is busy enough already. And as he approached his 90th birthday and people would say, “You don’t look it,” he had a ready answer: “That’s like telling an 8-year-old that he looks like a 4-year-old.”