The twins Kathy and Karth go on a mission to demonstrate time dilation. Karth will stay on earth while Kathy will board the Kathy Mobile (rocket) and orbit the earth at a certain speed. By changing the speed of the Kathy Mobile, we are able to see the difference between how Karth ages and how Kathy ages, thus illustrating the effects of time dilation.
https://docs.google.com/presentation/d/1i1NPqM1Ba2xksPA2nZoui4ETklF3N8lLqtfIXuE6yiU/edit