Teaching about Gravity using Science Magic

Using gravity you can cause an unattached rope to seemingly lift a bottle. As with all magic–its a trick. In this trick, gravity is used to pull a ball into place so that it presses so hard against the rope that it cannot move.

1. Ask an adult helper to cut a slit in the side of 1-quart (1-liter) plastic bottle with a small mouth (a larger or smaller water or soda bottle will work). The slit should be large enough to push a small rubber ball about the size of a walnut into the bottle. (If a ball is not available, mold a walnut-size piece of modeling clay into a ball.)

2. Hold one end of a 12-inch (30-cm) piece of thick cord or rope and drop the other end into the bottle.
3. Holding to the end of the rope extending out of the bottle, turn the bottle upside down. Shake the bottle so the ball rolls to the mouth of the bottle. With the bottle upside down, slightly pull down on the cord with one hand and slightly pull up on the bottle with your other hand. This causes the ball to press against the cord holding it securely.

4. Continue to pull on the rope in one direction and the bottle in the opposite direction as you turn the bottle upright.

5. Continue holding the rope as you release the bottle.

6. Set the bottle down with a bang, this should dislodge the ball and release the rope. The sound of the bottle hitting the surface also masks the sound of the ball hitting the bottom of the bottle.

7. Pull the rope out of the bottle.

What Happens?

The ball and rope are both stuck in the mount of the bottle. This allows you to support the bottle by holding the rope. and drop the rope into the bottle.

ADD THE MAGIC!

You do not want your audience to see what is going on inside the bottle. So, wrap the bottle with opaque paper. Aluminum foil can be pressed around the bottle or use construction paper. Make sure the paper is secure and that the paper covers the mouth but doesn’t  extend past the mouth of the bottle. If paper is used, squeeze it around the neck of the bottle and secure with tape.

What to Do:

Holding one end of the rope, insert most of the rope into the bottle, and then pull the rope out of the bottle.  to show that it does not get stuck inside the bottle.

Then as before, with the rope in the bottle, turn the bottle upside down. Shake the bottle as you turn it over so that the ball falls in place. Slightly pull on the rope to make sure the ball and rope are stuck in the bottle’s mouth. Keeping the rope straight and taut, turn the bottle right-side up. Holding the rope, release the bottle and if your magic is working the bottle appears to be suspended by the rope.