Mayo is surprisingly great at understanding nuclear fusion experiments

The texture of mayonnaise inspires love and hate. Either way, it’s perfect for physics experiments.

The classic seasoning is useful for understanding how materials behave, not only when spread on sandwiches or spread on potato salads, but also when used in nuclear fusion experiments. Mechanical engineer Arindam Banerjee of Lehigh University in Bethlehem, Pa., and colleagues are studying phenomena that occur in both mayonnaise and melting experiments.

Mayonnaise’s behavior lies on the borderline between elastic and plastic. If moved gently, it returns to its original shape. This is elastic behavior. But throw it hard and it becomes plastic, meaning it permanently changes shape or splits.

This elastic-to-plastic transition can also occur in experiments that use lasers to initiate nuclear fusion. In such experiments, lasers explode a metal capsule containing the fuel, raising pressures and temperatures so high that atomic nuclei in the fuel fuse together, releasing energy (SN: 16.2.24). Scientists hope to eventually use nuclear fusion as an energy source.

But it is difficult to study how materials behave in the extreme conditions required for melting. So, in their latest experiment, the scientists watched as the mayonnaise mixed with a gas—air—as they spun a wheel into which they had dropped the mayonnaise. The centrifugal force of the spinning wheel accelerated the mayonnaise into gas.

After the wheel stopped spinning, the scientists observed whether the orb returned to its original shape, changed shape, or split. This defined the boundary between elastic and plastic behavior, they reported in May Physical review E.

Mayonnaise and air are similar to the molten metal of a molten fuel capsule and the gas it contains. The molten capsule has some properties of a solid—like gooey mayonnaise, it doesn’t flow on its own—but it can shatter with enough force. If the metal becomes plastic before fusion occurs, the gas can escape, ruining the fusion effort.

Working with mayonnaise has one drawback. When you show up at the supermarket checkout line with 48 containers of mayonnaise, you’re going to attract attention. “Sometimes we get a lot of questions from grocery stores,” says Banerjee, “why are we buying so much mayonnaise.”