You can make hair stand on end using static electricity, often demonstrated with an object like a balloon.
Static electricity is a common way to make hair stand up temporarily. This happens when objects rub together, causing a transfer of electrons and building up an electrical charge.
Using a Balloon to Create Static Electricity
A popular method, as shown in the reference, involves using a balloon.
Here's how it works:
- Charge the Balloon: Rub an inflated balloon vigorously against another material, such as cloth (like wool or a synthetic sweater) or even your own hair. This rubbing action transfers electrons, giving the balloon a negative charge.
- Bring it Near Hair: Slowly bring the charged balloon close to someone's head of dry hair.
Reference Observation:
According to the reference, when rubbing the balloon over the top of hair, the hair stands on end. The video demonstrates this effect, stating, "As you can see the balloon is making my daughter's hair stand on end watch what happens when I move it. Around."
The Science Behind It
Hair stands on end due to the principles of static electricity:
- Charge Transfer: Rubbing the balloon against certain materials causes electrons to move from the material to the balloon, giving the balloon a negative charge. Your hair, in this case, likely loses some electrons or becomes polarized.
- Attraction and Repulsion: Your hair strands become either positively charged (by losing electrons) or become polarized with the positive ends facing the balloon. Each individual hair strand also tends to have a similar charge to its neighbors. Objects with opposite charges attract, which is why the hair reaches for the balloon. Objects with the same charge repel each other.
- Hair Repulsion: Because each strand of hair has acquired a similar charge (or is polarized similarly), they repel each other. To get as far away from their equally charged neighbors as possible, the individual hair strands push away from each other and stand upright, reaching towards the oppositely charged or polarizing balloon.
This creates the visual effect of the hair "standing on end," following the movement of the charged object.
