# Balancing Glass Trick

This system of knives and bottles will make you hold your breath as a full glass balances over them.

Table tricks are all the rage when it comes to post-dinner “oohs” and “ash.” That's why you need to keep the hits coming! For instance, give the Balancing Glass Trick a try. All you need are some knives, bottles, and a drinking glass. Before you know it, you'll be wowing your audience with a glass that seems to defy gravity and the laws of physics.

## Experiment Materials

• Drinking glass
• Three butter knives (same size & style)
• Three empty glass bottles
• Water

# Experiment

1. Place three glass soda bottles at an equal distance apart. They need to be close enough that the knives can reach from the bottles' mouths to the center.
2. Intertwine the knives in the fashion shown in the picture, where the blade of one knife lays atop the handle of another.
3. Rest the knives atop the bottles. The handle of the knives should sit on the mouths of the bottles. The knives will stay intertwined.
4. Set a drinking glass on top of the knives at the spot where they all intersect. The cup will sit safely.
5. Pour water into the glass, and watch as the apparatus remains steady.

# How Does It Work?

This appears to be complete and total magic, but the key is the point at which the knives intertwine. The blades of the butter knives are intertwined in a weave. Each knife goes underneath a second knife while going over the top of a third. This “weave' makes it so that, when pressure is applied to all three knives, force is being applied downward and upward. With the handles of the knives resting on the glasses, and the fourth glass resting at the intersecting points of the knives, balanced forces enable the full glass of water to remain stationary atop the knives.