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Magicians sometimes do tricks where they make things float: balls, animals, their lovely assistants, and even themselves! We know that magic is an illusion and there’s always a trick to it behind the scenes. In today’s Saturday Science, we’ll learn one trick to make things levitate and float around. It’s some very simple science that appears to be magic. You’ll look like you’re defying gravity!
Materials:
- Balloon
- Produce Bag (the kind you put fruits and vegetables in at the grocery store)
- Scissors
- Old rag or washcloth
Process:
- Blow up the balloon. Make sure it’s nice and big.
- Have a grown-up help you with the scissors and cut a one inch ring off the top of the produce bag. All you have to do is flatten it out and cut straight across an inch or so down from the bag’s opening.
- Place your plastic bag ring on a dry table or countertop. Using the old rag or washcloth, rub down the plastic ring. Go in the same direction 5-10 times until you start to hear a crackling sound and the hairs on your arm start to stand up. This charges the ring with static electricity.
- Now you need to charge your balloon with static. Hold it in one hand and rub it with the washcloth in a circular motion, always going in the same direction. It may be hard to do without dropping the balloon. If you’re having trouble, try holding it between your knees or having a grown-up hold it for you while you charge it up.
- Now it’s time to levitate! Gently peel your plastic ring off the table. Make sure you only touch the very end of it because if you touch more it might lose its static charge. Hold the balloon in one hand and hold the plastic ring above it in the other. Drop the ring and try to balance it in the air as it floats above the balloon. This will take some practice because the ring wants to stick to everything but the balloon, but once you’ve figured it out you’ll be a levitation master!
What's going on?
Have you ever been walking on some carpet on a dry day and then touched a doorknob and gotten a static shock? That’s static electricity in action and it’s the scientific force that allows us to levitate the ring above the balloon.
All the matter in the universe is made of tiny pieces called atoms, and those atoms are made of tiny pieces called protons, neutrons, and electrons. Electrons are really easy to remove from atoms, though, especially when things are dry. That’s what happens when you rub your feet on the carpet. When you’re walking on the carpet, the friction of your feet on the carpet steals electrons from it and adds them to your body. When you touch the metal doorknob, the electrons jump to it and create that shock.
With our plastic ring and our balloon, we’re doing the same thing but creating a different effect. When you rub the plastic with the washcloth, you’re giving the plastic extra electrons. When you rub the balloon, it’s getting extra electrons, too. Electrons have what’s called a negative charge, so objects with extra electrons also have a negative charge. And here’s the cool thing about electrical charges: like charges repel, or push each other apart. So when you have a balloon with a negative charge and a plastic ring with a negative charge the balloon will push up on the ring and make it float!
Once you have some practice try getting creative with your static levitation. The balloon and the ring push each other apart in every direction, not just up and down, so try pushing it around the room without letting it hit the ground. Your hand attracts the ring, since they have different charges and different charges attract each other, so see if you can pull it around the room like a psychic while it balances above the balloon. If you break or lose your ring, just cut another one off of the bag and keep levitating!
