Mayonnaise's texture evokes both love and disdain, yet it's ideal for physics experiments. This traditional condiment aids in understanding material behavior, whether it's spread on sandwiches, added to potato salads, or utilized in nuclear fusion research. Mechanical engineer Arindam Banerjee from Lehigh University in Bethlehem, Pennsylvania, and his team are investigating phenomena shared by mayonnaise and fusion experiments.
Mayonnaise exhibits a behavior that straddles the line between elasticity and plasticity. When lightly jostled, it reverts to its original form, demonstrating elastic behavior. However, when thrown with force, it becomes plastic, meaning it either permanently changes shape or breaks. This transition from elastic to plastic behavior also occurs in fusion experiments that employ lasers to initiate nuclear fusion. In these experiments, lasers bombard a metal capsule filled with fuel, creating extreme pressures and temperatures that cause the fuel's atomic nuclei to fuse, releasing energy.
Studying material behavior under the extreme conditions necessary for fusion is challenging. Therefore, in their recent experiment, the scientists examined how mayonnaise mixed with air behaved as they rotated a wheel coated with the condiment. The centrifugal force from the spinning wheel propelled the mayonnaise into the air. After the wheel ceased spinning, the scientists observed whether the mayonnaise returned to its original shape, altered shape, or fragmented. This helped determine the boundary between elastic and plastic behavior, as reported in the May issue of Physical Review E.
The interaction between the mayonnaise and air mirrors that between the molten metal of a fusion fuel capsule and the gas it contains. The molten capsule, like mayonnaise, doesn't flow on its own but can break apart under sufficient force. If the metal becomes plastic before fusion, the gas might escape, thwarting the fusion attempt. Using mayonnaise in experiments does have one downside: purchasing 48 containers of mayonnaise at the supermarket checkout tends to draw attention. "We often receive inquiries from grocery stores about why we're buying so much mayonnaise," Banerjee remarks.
