On this weekend ahead of the US election, we clock the importance of so-called swing states – and swing into action looking into not politics, but the science of swings. We examine how a pendulum swung by French physicist Foucault demonstrated that the earth is spinning, and hear about how the gibbon became the king of swingers – and what current-day elite climbers can learn from them. We also hear from educator Francis Mavhunga at the University of Eswatini who has regularly used swings in his physics classes, and now shows a new generation of teachers how to integrate children’s lived experiences into the classroom. Plus, how science has revealed new secrets about the ancient silk road, and what your brain can see when your eyes can’t. And, just to swing back to the beginning, presenter Marnie Chesterton digs into the archives to find out if science and tech can provide a foolproof voting system, and how astronauts vote. Presenter: Marnie Chesterton with Chhavi Sachdev and Godfred Boafo Producer: Harrison Lewis with Florian Bohr, Julia Ravey, Dan Welsh and Imaan Moin Sound Engineer: Gareth Tyrrell