Spinning Tops, Underwater Boats, and the Mighty Elephant

Why Doesn’t the Dreidel Fall Over?

Ever wondered how a dreidel can spin and not fall? The secret is in the spin. When the dreidel spins, it creates something called "angular momentum" which means it keeps turning around its center. As it tilts, gravity pulls one side down, but the spin quickly shifts that side back up, and another side tips down instead. This keeps happening again and again, which helps the dreidel stay standing for a while before it finally falls.

Who Came Up With the Submarine?

Back in 1578, an English inventor named William Bourne came up with the idea for a submarine. Around the same time, Leonardo da Vinci also drew some sketches of one. But the first working submarine was built in 1620 by a Dutch inventor named Cornelis Drebbel. He used Bourne’s ideas and tested the boat in England’s River Thames. It could go underwater to a depth of about four meters.

What’s the Strongest Mammal in the World?

When it comes to strength, the elephant is the champion among mammals. A grown elephant can carry about 9 tons on its back, that’s like carrying 130 adults or around 250 kids! Elephants are also loud. Their trumpet sound, made through their trunk, can reach 110 decibels. That’s really loud and helps them send messages to each other across long distances.