Marble Gravitron

1. This is very important: it only works with a glass that is narrower at the top like the one on the left in this picture. Wine glasses work best - the glass on the right in this picture won't work at all.

2. Trap a marble (or any spherical object) under the glass on a smooth surface.

3. Wiggle the glass and the marble will start rolling around inside really fast. Look carefully and you'll see it starts 'climbing the walls'.


Note: the marble is just a faint blur in this photo

4. When the marble is really hooting along, lift up the glass and the marble stays inside. With some glasses, you can keep the marble inside as long as you keep wiggling.


Note: you can just see the blur of the marble between my middle and ring fingers in this photo.