Science now has an answer to the famous question asked in the iconic Tootsie Roll Pop commercial: about 1,000. And you can take that number to the bank — it's based on a sophisticated mathematical model of how flowing fluid dissolves solids.
Researchers at New York University arrived at the number by custom-making their own candy spheres and cylinders to test how materials dissolve in a flow. But this seemingly simple process is actually quite complex, said study leader Leif Ristroph, a physicist at NYU. First, the presence of the solid disrupts the flow, forcing it to bend and change directions, he said.
"But then, the flow starts to dissolve the solid, so now something about the flow is being imprinted on the solid object," Ristroph told Live Science. "What happens is, you get a weird feedback between the two."