1) The world's first credit card was introduced in 1950 by Diners Club.

2) The first photograph of a black hole was captured in 2019 using a network of telescopes around the world.

3) The highest mountain in Africa is Mount Kilimanjaro, standing at 19,341 feet (5,895 meters) tall.

4) The strongest natural material known to man is spider silk. It is stronger than steel and more flexible than nylon.