Fun facts: Hamburgers, teeth, eyes and hair

Fun Fact
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Fun FactWhere 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.

How strong is a strand of human hair?
A single strand could hold 100g in weight: the combined hair of a whole head could support 12 tonnes or the weight of two elephants. Weight for weight, it is not as strong as steel: more like aluminium, or reinforced glass fibres or Kevlar, which is used to make bulletproof vests.