(*1*) Comparing how fast a ball would fall 1 meter on the surface of different celestial bodies [reupload with timing fixed] Read more »
Flight of Ingenuity — First powered flight on another world Read more »
Antique safe made in France around ~1780 / 1810. With three keys and a combination of ordered changes. Read more »
Comparison of the height one can jump on each planet, and the moon, if the same jumping force is utilized. Read more »
Mechanism of a Janney coupler (likewise know as American or knuckle) Read more »
Cone of Apollonius: Slicing a cone with a plane will produce the famous curves known as the conic areas. Read more »