Why Do Leaves Fall? And Other Surprising Facts

Why Do We Say Ship Speed in “Knots”?
Long ago, sailors used ropes with evenly spaced knots to measure how fast they were going. They’d drop the rope in the water and count how many knots passed through their hands in a set time. That’s why ship speed is still measured in “knots” today each knot equals about 1.852 kilometers per hour.

What’s the Difference Between Celsius and Fahrenheit?
The Celsius scale is based on water: 0° for freezing and 100° for boiling. The Fahrenheit scale starts from the freezing point of salty water. And there’s also the Kelvin scale, which starts from the coldest possible temperature, absolute zero, which is minus 273°C!

The Smartest Parrot Around
The Grey Parrot is not only beautiful but it’s also one of the smartest birds in the world. It can copy human speech better than any other parrot species and understands a lot of what it hears!

Can You Believe Glass Comes from Sand?
Yes, it’s true! When sand is mixed with lime and soda and heated to over 1000 degrees, it melts and turns into glass. Today, we use a more refined method, using silicon dioxide from sand and other ingredients to make the clear glass we know.

How an Apple Helped Discover Gravity
When Isaac Newton was just 23 years old, he saw an apple fall from a tree. That simple moment made him wonder: why did it fall down? This led him to explore gravity and later, to write the famous laws of motion and gravity.

A Natural Wall That Stops Waves
To protect beaches from strong ocean waves, people often build wave breakers. But at Vega Baja Beach in Puerto Rico, nature already did the job! A row of large rocks sits close to the shore, naturally blocking big waves from reaching the beach.

Why Do Leaves Fall in Winter?
During winter, trees have a hard time sending nutrients all the way to their branches and leaves. When the leaves stop getting what they need, they slowly weaken and fall off. This helps the tree save energy until spring arrives again.