How is an air chamber formed in an egg?

There is an air chamber in any chicken egg. This is the area between the protein and the shell that contains only air. The reason for its formation is directly in the difference between the temperature of the newly laid egg and the surrounding air. The body temperature inside the chicken is high, about 40 degrees. A fresh egg is warm and the air chamber is very small. As the egg cools, the amount of air in the air chamber increases, as the temperature of the contents under the shell decreases by several degrees. Therefore, by the size of the air chamber, one can judge the freshness of the egg.