Cory Heid took a math view to solve how many licks it takes to reach a Tootsie Pop’s center.
LUNA PIER, Mich. — Cory Heid faced a problem as he considered what to do for the senior project he needed to graduate from Siena Heights University.
“I wanted a real-world application problem, and I kept coming up with ideas that my adviser said ‘nah, nah,’ to,” said Mr. Heid, who graduated in December with an applied mathematics degree.
Then the Luna Pier resident, 23, considered the Tootsie Pop, the famous candy lollipop, and the commercial that asked, “How many licks does it take to get to the Tootsie Roll center of a Tootsie Pop?” He wondered, did the question lend itself to scientific inquiry?
He would find out that it did, and his finished project attracted attention. He presented his results in January at the Joint Mathematics Meetings in San Diego to a standing room only audience of 400 people, and will have another presentation next month at the Joint Statistical Meetings conference in Montreal.
He believes he attracted such a large audience in San Diego because “it wasn't a boring topic,” and hopes for the same or greater numbers in Montreal.
When he began the project at SHU, he quickly found that he was not the first person in an academic setting to tackle the Tootsie Pop problem.
Indeed, he came across research from Harvard and Purdue universities, the University of Michigan, Swarthmore College, and the University of Cambridge, in England.
These researchers came up with, as he put it in a blog entry on the project, “very different answers.” Their number of licks ranged from 90 to 1,000. His came in at an average of 356.
The differences aren’t surprising when you consider that Tootsie Pops are not of uniform size, he said.
He learned this characteristic early in his research when he used a micrometer to measure the pops.
He found Tootsie Pops could vary by 4 millimeters in height and 2 to 3 millimeters in width.
Similarly, there are variables in people’s tongue size, body temperature, and saliva that can affect the number of licks, he said. When his project reached the point where it needed volunteers, he recruited 80 of them from SHU math classes.
Tim Husband, chairman of SHU’s mathematics department and Mr. Heid's adviser, said this variability significantly complicated the Tootsie Pop experiments.