This video is chapter 8 in my series on special relativity, and it presents a hands-on explanation of the resolution to the Twins Paradox using the mechanical minkowski diagram, aka mechanical Lorentz transformation, aka spacetime globe. Of course, the Twins paradox can be resolved with an understanding of spacetime intervals, relative inertial frames of reference, etc, but this is a nice hands-on version where you actually measure the proper times on a real, physical spacetime diagram with a ruler.