14 incredible facts you didn't know

14 INCREDIBLE FACTS YOU DIDN'T KNOW

1. Vikings never wore horned helmets. This myth appeared thanks to theatrical productions of the 19th century. Such helmets would have been impractical in battle.

2. The sound from a seashell is not the sound of the ocean. It's just an echo of the surrounding noises. In a completely quiet room, the shell doesn't "say" anything.

3. Casinos have no windows or clocks. Everything is designed so that visitors lose track of time and stay in the game longer.

4. Rice grains and a chessboard. If you double the number of grains on each square, the last square would contain more than 460 billion tons of rice - 1,000 times more than is harvested annually worldwide.

5. Diamonds form at a depth of 200 km. They rise to the surface only due to volcanic eruptions. Their age is about 1.5 billion years.

6. The story about Newton's apple is a myth. It was first told by Voltaire, but Newton himself never mentioned it.

7. "Money doesn't smell." Roman Emperor Vespasian introduced a tax on public toilets. When criticized, he offered senators to smell the money received from the tax.

8. Water can boil and freeze simultaneously. This phenomenon is called the "triple point," when a substance exists in three states of matter at once.

9. Honey is the only food that doesn't spoil. A jar of honey found in Egyptian pyramids remained edible after thousands of years.

10. You can't cry in space. Due to zero gravity, tears don't flow down but remain on the eyes, forming bubbles.

11. Tadpoles can regrow their tails. Some frog species have the ability to regenerate, even restoring lost limbs.

12. There is a "blood" waterfall in Antarctica. Its red color comes from the high concentration of iron in the water, which oxidizes in the air.

13. Humans have second eyelids. The remnant of a third eyelid, called the semilunar fold, can be seen in the inner corner of the eye.

14. Octopuses have three hearts. Two of them pump blood through the gills, and the third throughout the body. When an octopus swims, this heart stops.