From Compass to Penny Black: Fascinating World Facts

• Who invented the computer mouse?
We all know names like Einstein and Edison, but the person who invented the computer mouse isn’t as famous. Douglas Engelbart, who worked as a radar technician in World War II, came up with many computer ideas, especially related to how we use screens and images. He started working on the mouse in the 1960s and later won a Turing Award for his big contributions to computer science.

• How does an X-ray machine work?
X-rays can pass through soft parts of the body but not through hard things like bones. That’s how we get clear pictures of bones inside the body. Older X-ray machines used radiation tubes or special particle machines, but today most X-rays are taken digitally, thanks to modern photography.

• Who invented the compass?
The compass is one of the oldest tools used to find direction. It works by using the Earth’s magnetic field and always points north. The Chinese say it was invented by the Yellow Emperor, but it's possible someone else created it, and the credit was taken. It likely started in China and arrived in Europe in the 1400s.

• How did the old rotary phone work?
The old-fashioned phones with a spinning dial worked by sending a certain number of electric pulses with each number you dialed. Once the full number was entered, the phone would connect you to the right line.

• What is albinism?
Albinism is a condition where a person’s body doesn’t make the usual pigments that give color to the skin, hair, and eyes. People with albinism have very light or white hair, pale skin, and often light-colored eyes.

• How much is the world’s first stamp worth?
The first stamp ever used was called the Penny Black. It was made in Britain, showed a picture of Queen Victoria, and cost just one penny. Today, an original Penny Black is worth a fortune, about 153,000 British pounds!

• What is the Australian Outback?
The Outback is a huge desert area in Australia. Until around 70 years ago, it didn’t even have an official name. This wide, empty land covers 130,000 square kilometers and is one of the most remote places on Earth.