We have already seen many simple science experiments with eggs, which we can do at home. There is the transparent egg experiment, floating egg experiment, and many more experiments that we can do with the help of eggs. This experiment is about making an egg move on its own. In this egg in a bottle experiment, you will see an egg sliding into a bottle, all on its own! Does it sound creepy? Well, this is pure science!
What we need
Eggs
Glass bottle
Water
Bowl
Paper (preferably thick sheet)
Matchbox / Lighter
Procedure
- The first step in the experiment is to boil the eggs. Place the eggs in the bowl, pour water, and boil it over the stove. Keep boiling for 10 to 12 minutes. We need the eggs to be hard-boiled.
- When the boiled eggs cool down, remove the egg shells. Now we have the eggs ready for our experiment.
- Next step is with the glass bottle. Always remember, the bottle opening should be of the right size. The opening should be slightly smaller than the size of the egg, but not too narrow. (If it is too narrow, your egg will refuse to move inside)
- Fold the paper into a thick and narrow strip that will fit into the bottle.
- Light the paper using the lighter or matchstick. Drop the burning paper into the bottle. (Adult supervision is advised for this step)
- Before the fire goes out, place the egg over the bottle opening. Wait for the magic to happen.
- In a few seconds, the fire goes out. And you will see the egg squeezing itself into the bottle. It may break into pieces during the drop into the bottle, but you will definitely see the egg moving inside, on its own!
What we learn
What do we learn from this egg in a bottle experiment? How did the egg get sucked into the bottle? This magical movement of eggs was caused due to the difference in air pressure. So let us try to decode the concept of air pressure.
Air exerts pressure on everything on Earth. In simple words, air pressure or atmospheric pressure over an object refers to the pressure exerted by the air column above it. Air exerts pressure on our bodies as well. But we do not feel it, as the air pressure inside and outside the body are balanced.
At the beginning of our experiment, the air pressure inside and outside the bottle was the same. When we dropped the burning paper into the bottle, it heated up the air inside. Hot air expands and rises up. Then we closed the bottle opening with the egg. When the oxygen inside the bottle is used up, the fire goes out. The air inside the bottle eventually cools down.
What happens when air cools? It contracts and takes up less space. Thus the air pressure inside the bottle becomes lesser than the air pressure outside it. Air pushes the egg from above, and as the boiled egg is flexible, it easily gives in to the pressure. So the egg moved inside without any external force. This is how air pressure played its role in this magical experiment.
