Physicists solve nuclear fusion mystery with mayonnaise

Nuclear fusion technology could get a breakthrough from an unexpected place: mayonnaise.

In a new study, published in May in the journal Physical Review E, scientists plopped the creamy condiment into a churning wheel machine and set it whirling to see what conditions made it flow.

"We use mayonnaise because it behaves like a solid, but when subjected to a pressure gradient, it starts to flow," study lead author Arindam Banerjee, a mechanical engineer at Lehigh University in Pennsylvania, said in a statement.

This process could help elucidate the physics that occur at ultrahigh temperatures and pressures inside nuclear fusion reactors — without having to create those extreme conditions.

Related: World's largest nuclear fusion reactor is finally completed. But it won't run for another 15 years.

Nuclear fusion forges helium from hydrogen at the hearts of stars. In theory, it could be the source of nearly limitless clean energy on Earth — if the reaction could produce more energy than it requires to run.

That's a tall order; star-powered fusion occurs at 27 million degrees Fahrenheit (15 million degrees Celsius), according to NASA. And a star's massive gravity forces hydrogen atoms together, overcoming their natural repulsion. On Earth, however, we don't have those crushing pressures, so human-made fusion reactors must run 10 times hotter than the sun.