Video transcript of Episode 9: Electric Balloons
On-screen text reads: "On-screen text reads: "Do Try This at Home from the Institute of Physics. Episode 9: Electric Balloons."
Camera cuts to Lucy who is looking towards the camera. She is holding a balloon to hair and her hair is rising to meet it. If she moves the balloon, her hair moves as well.
We hear a whooshing noise accompanied by a short animation.
Camera cuts to Lucy who is sitting behind a kitchen table. There are a couple of balloons, two lengths of string and some tape on the table.
Lucy: "Welcome to Do Try This at Home brought to you by the Institute of Physics. We’re making these films because we want to help parents and carers in the UK and Ireland get their kids excited and curious about the world around them, and you don’t need to leave your home to do it."
On-screen text reads: "Lucy Kinghan, IOP Public Engagement Officer (Ireland)."
Lucy: "My name is Lucy and you’re very welcome to join me again in my home.
"This time I’ve moved to the kitchen, and I’ll be doing a new demonstration called the Electric Balloons. I love this demonstration because it takes something that we’re all familiar with in some way, in this case rubbing a balloon on a jumper or on our hair, and it just does something a little bit extra with it.
"It should be a positive experience for everyone, especially if you’ve been left in charge of the family for the afternoon.
"For this demonstration you’ll need two balloons, you’ll also need string, or you can replace this with wool or thread, basically anything that’ll help you hang the balloons. You’ll also need some Sellotape, and you’ll need a woolly jumper, or you could use a cloth, or you could use your hair, or you could try out a few other things."
As she speaks, Lucy points out the balloons, the two pieces of string, and the Sellotape on the table.
We hear a whooshing sound as the screen swipes right.
Camera cuts back to a medium shot of Lucy.
Lucy: "To get started we’re going to blow up both the balloons and tie them."
Lucy picks up the first balloon and we hear her blowing into it. She ties a knot in the neck of the balloon to prevent it deflating. She pinches the neck of the balloon and stretches it out, creates a loop which she threads her fingers into, pulls the lip of the neck through the loop and then pulls her finger out of the loop. We hear her place the balloon down on the table.
Lucy: "One balloon done."
Lucy repeats what she has done. She blows up the second balloon and ties a knot in the neck
Lucy: "Next, we’re going to take our string and we’re going to tie it around the knot of the balloon."
Lucy sits the first balloon on the table so the knot points upwards. She then picks up one of the bits of string and creates a loop around the knot. She then threads the short end of the string through the loop and pulls both ends of the string tightly. Her hands are resting on the balloon as she does this to prevent it rolling away from her.
She then places the balloon down and repeats with the second balloon.
Lucy: "All right we’re gonna find somewhere where we can hang the balloons. You could do this over a doorframe or from some hanging lights or as I’m going to do over my cooker."
We hear a whooshing noise and the screen swipes right.
The camera cuts to Lucy standing next to her cooker. She has taped the string at the end of each balloon to the hood of her cooker. The balloons are hanging straight down and just touching each other.
Lucy: "So I’ve hung both my balloons from my cooker, but you could also hang them from the middle of your doorframe or from some hanging lights wherever you feel is suitable in your house. The important thing to remember is that the sides of the balloons are just touching when you let them hang straight down.
"On the spot where the balloons are touching, we’re going to rub each balloon with our jumper, a piece of cloth or our hair. You can try different things around the house to see what gives you the best results, or you could follow my example because I’m going to use a glass."
Lucy picks up an empty drinking glass. She pulls the balloon towards her and holds it with one hand. We can hear her as she rubs the side of the balloon with her glass. She then does the same with the second balloon.
When she has finished, we see that the balloons are no longer touching and have pulled away from each other.
Lucy: "Bring the sides of the balloons that we’ve just rubbed close together and this time you’ll see that the balloons move away from each other."
Lucy tries to bring one balloon closer to the other but the other balloon pulls away.
Camera cuts to a close-up shot of the balloons repelling each other.
We hear a whooshing sound, the screen swipes right, and the camera cuts to Lucy who is now sitting down behind the kitchen table.
Lucy: "So, what’s going on here and how can you explain it to your family?
"The interesting physics happens when we rub each balloon. Pretty much everything you come across is made of atoms."
Camera cuts to an image of the two balloons repelling each other.
We hear a whooshing sound, and the camera zooms in on the balloons.
Lucy (voice-over): "If we zoom in every atom has a positively charged centre with negatively charged particles called electrons around it."
The balloon is replaced by a drawing of an atom. There is a small dot in the middle and a much larger circle drawn around it. The camera focuses in on the dot so that it’s much bigger. A plus sign appears in the middle of the dot.
Camera cuts to the outer circle and we see a negative symbol appear over the circle.
Camera cuts to a medium shot of Lucy.
Lucy: "Each atom has the same amount of positive and negative and these charges cancel each other out."
Camera cuts to a close-up shot of Lucy rubbing a drinking glass on the side of a balloon.
Lucy (voice-over): "When we rub two things together, we’re moving electrons from one material to another.
We hear the sound of the bell, and an arrow appears. The arrow has a negative symbol over it and points from the glass to the balloon."
Camera cuts to a medium shot of Lucy.
Lucy: "Is this something you’ve seen done before? You might have made each other’s hair stand up on end like this."
Camera cuts to Lucy who is holding a balloon close to her hair. Her hair is rising to meet it. If she moves the balloon, her hair moves as well.
Camera cuts to Lucy who is talking on screen.
Lucy: "My hair is pretty rubbish at holding onto its own electrons and the rubber of the balloon is quite good at it, so when I rub the balloon with my hair, the negatively charged particles are rubbed off my hair, and onto the balloon."
Camera cuts to Lucy holding the balloon to her hair. We hear a bell, and an arrow appears. The arrow has a negative symbol over it and points from Lucy’s hair to the balloon.
Camera cuts back to Lucy as presenter.
Lucy (voice-over): "As more and more electrons get built up on the balloon the whole balloon develops a negative electric charge.
Camera cuts to Lucy who is holding the balloon close to her hair. This time we see a plus sign image on her hair, and a negative sign on the balloon.
Lucy (voice-over): My hair has lost electrons and has the opposite charge, a positive electric charge.
Camera cuts to Lucy who is back on screen.
Lucy: "Opposites attract so when I lift up the negatively charged balloon my positive hair lifts up as well.
"What about the two balloons?"
Camera cuts to a close-up of the two balloons. The balloons are trying to pull away from each other. We hear the sound of a bell, and a negative sign appears over each balloon.
Lucy (voice-over): "When I rub the balloons, they both end up with a negative charge and they certainly aren’t trying to get close to each other. Materials that have the same electric charge repel each other which is why these balloons keep their distance."
Camera cuts to Lucy who appears back on-screen.
Lucy: "Don’t worry if you’re unsure about the science though. As always have fun together, test it out together and then look it up together if you need to.
"Thank you for watching and see you next time."
The image is replaced by some on-screen text which reads: "Do Try This at Home from the Institute of Physics. For instructions and more Do Try This at Home films visit iop.org/athome. These experiments have not been specifically safety tested for home use, but we believe them to be safe if the instructions are followed. Adult supervision is recommended as appropriate. All experiments are carried out at your own risk."