The rotation of the Earth's core is slowing: what does it mean for us?

Much like the plot of the 2003 disaster film, The Core, the rotation of Earth’s inner core is changing. But unlike the movie, this change is very subtle. What exactly makes up the Earth’s core? And how significant is its rotation change? Swarthmore College Professor of Astronomy Dr. Eric Jensen explains how scientists made this new discovery and what it could mean for the future.