[Wuli]

The most plausible solution, Helffrich explained, is that expulsion of light elements from the inner core liberated what is called gravitational potential energy. As this lighter liquid rose upward, it imparted energy downward that drove the flow of metal in the core, which in turn helped keep the magnetic field running. "That fits with the wave speed profile that we observe," Helffrich said.

Then a question for those scientists might be:

If that hypothesis is proven to be correct, might it also be possible that:

a. The lighter elements in the outer layer of the core, over time, also, slowly, migrate out of the core altogether, ??? and

h. Might that migration step be part of the continuing energy imparted to the "spinning" of the core, and;

c. If that were true, then might the process that set the core spinning, one day lose 100% of the lighter elements from the core, through migration from the core, and eventually cause the core to stop spinning?