We entwine both forks with the toothpick and leave the set in balance in the edge of a glass. The balance is achieved when the gravity center of the set is below the point of support.
What does happen if we burn the end of the toothpick that is inside the glass?
A part of the toothpick burns but the flame goes out when coming at the edge of the glass and the balance of the forks is kept. The loss of mass of the toothpick that has burnt not affect significantly the gravity center that continues below the point of support.
By Inma and Pía