A muscular hydrostat: an arm with no bones, moved by muscle alone at constant volume. Start in 3D to calibrate your eye, then switch to 4D. Drag to turn the view. physics gives the arm mass, water and self-contact (off: the shape its muscles ask for, at once). knot ties a length of arm in an overhand knot and pulls; pull slackens or pulls again, retie starts over. In 4D the pad twists your slice into w (J L, I K), the lever moves it ana and kata (R F), ⊞ or Z squares it up. how it works · kata · SQUID