One Cone, Four Curves

Interactions

Drag the glass sheet: sideways tilts it, up and down raises it on its stand; the cut, the string pins and the lamp all follow, then the slow program resumes
Drag either string pin: the fixed loop of string re-shapes the ellipse the pencil draws (pins apart flatten it, together make a circle), then the pins drift back
Drag the launch arrow by the sun down or up and let go: a new body is launched at that speed and inks its circle, ellipse, parabola or hyperbola
Click the lamp: the shade swings free of the glass on its hinge and the light on the wall runs through other conics before the link takes it back
Click the thrower: she lobs another ball over the fountain into the pail