How is it possible that Phil can press some thumb tacks into a balloon and it doesn't go POP!? It's all down to the distribution of pressure.
Have a look at the Hub Lab experiment above. Now, if you want to give it a go be really really careful and have an adult present so you don't hurt yourself with a thumb tack!!
What are we learning in this Hub Lab?
1. How balloons work!
2. Pressure distribution
3. Materials and elasticity
What is happening?
What happens when you blow up a balloon and stick a thumbtack into it? It pops! Balloons tend to pop when the air pressure inside is stronger than the actual material of the balloon itself.
Sticking a pin into a balloon will weaken the material in one concentrated area and cause it to pop! If we lay out lots of pins on a table and press the balloon down on it, it will not pop!
This is because the pressure is now spread out over a much wider area. The force of you pushing down is now spread out over lots of pins meaning the tensions is less on each pin. If you used the same force to push down on one pin, you'd pop the balloon!
This is the same physics behind someone lying on a bed of nails, standing on one nail may hurt you, but people can lie on beds of nails as their body weight is spread out evenly….just don’t try this at home!
Download the full experiment with the procedure here!