The video shows how to see the yolk in the egg without destroying the egg. An experiment you can also do with children in the kitchen.
Also of Interest
Video: Bouncing Egg
An egg behaves like a bouncing rubber ball
Video: Is the Egg Raw or Boiled?
Simple experiment that easily can be done in the kitchen with small children
Article: Boiled Eggs: Soft and Hard
When we rap a knife on the shell of a freshly boiled egg we are seldom aware of what a technical marvel we are dealing with
Extinguished candle pulls egg through bottleneck