After I had too much pain in my knees running, I decided to switch to a lower impact exercise. The obvious choice would have been cycling, but I discovered rowing and liked the fact that it trains more muscles, because it also exercises the upper body. I like to be efficient with my exercising. I don't have all day just to exercise. An exercise that engages more of my muscles is therefore more time efficient. It also produces lower joint impact than running. Cycling is even lower impact than rowing,...
Go figure this one out. Three boxes, big, medium, small, stacked inside each other. So far so good. But hey, what is this? The small box is now large enough to hold the medium and big boxes?
This is my rendition of Lubor Fiedler's ingenious Gozinta Boxes (also known as Parabox or Inside-Out box). (The reason I am touching the boxes so gingerly is that they are 20 years old made from now brittle cardboard. Nevertheless, this effect is one of my favorite illusions.)
For those who know...