About this tube

A soft jelly can fit through a tube that is narrower than it is.

The tube is only about two thirds as wide as the jelly. Push him in and watch what happens to his shape.

The jelly inside can't vanish, so when part of him is squeezed thin, that part gets longer. The squeezed middle becomes a long sausage, and the parts still outside stay round and plump. A bigger jelly has more to move, so the sausage is longer. Slide him back and forth and it all undoes itself.

Now make him firm. A firm jelly can only be squeezed so far (the softness slider is how far). If the tube asks for more than that, the widest part stops at the rim and he's stuck, with his nose in the tube. Make him softer or smaller and he'll pop through. At full softness any size fits: a plump jelly just becomes a longer sausage (more in Why jelly wobbles).

Drag him with your finger, or use the sliders. The jelly is worked out live in your browser.