Part of the show Dinosaurs and Fossils - Jurassic Science set in Stone
What you Need
What to do
Spin an egg on a table,
Stop it quickly with your finger, and then release it.
Try with the other egg.
Is there any difference?
What may happen
Why does it happen?
The centre of a raw egg is quite liquid so even if you stop the shell moving the centre will keep going for a short time.
A hard boiled egg on the other hand is solid so if the shell is stopped so is the centre.
Why was the raw egg so difficult to start spinning?
In the same way that it is hard to stop the egg because the centre is liquid, it is hard to start it moving quickly. So even if you spin the shell very quickly the centre will not be moving, so it the shell will quickly be slowed by the friction between it and the centre.