Fun facts: Hamburgers, teeth, eyes and hair

Where did hamburgers originally come from?
German cook Otto Kuasw created a very popular sailors’ sandwich made of a fillet of beef patty fried in butter, served with a fried egg, between two toasted buns in 1891, at a post in Hamburg, Germany.

Why do our teeth chatter when we are cold?
When it’s cold outside and your body temperature starts to drop, the hypothalamus sends a message to your body that it needs to warm up. One way it does that is through your muscles, which generate heat by shivering. Teeth chattering is just a form of shivering.

Do your eyes ever grow?
The eyeball is fully grown when you are born. When you look at a baby’s face, you see mostly iris and little white. As the baby grows, you get to see more and more of the eyeball.