How Does a Stethoscope Work?
How Does a Stethoscope Work? A stethoscope allows the doctor to hear the sounds your body makes inside. In order to do this, the doctor presses the listening piece...
Read More
When Was Music First Written down?
When Was Music First Written down? No one is certain when music was first written down. We do know, however, that the ancient Greeks wrote music with the letters of...
Read More
Who Invented the Board Game Snakes and Ladders?
Who Invented the Board Game Snakes and Ladders? Snakes and Ladders, is an ancient Indian board game regarded today as a worldwide classic. It is played between two or...
Read More
How Does a Submarine Go up and down?
A submarine is different from other ships, though, because it can control its buoyancy. This means the submarine captain can decide when to sink down into the ocean or...
Read More
What Is Acid Rain?
Acid rain is created when rain mixes with pollution in the air. Pollution fills the air with an invisible gas called sulfur dioxide. (This gas is mainly a result of...
Read More
Why Does a Train Whistle Change Its Pitch When It Passes?
Why Does a Train Whistle Change Its Pitch When It Passes? You may have noticed that the pitch of a train whistle seems to rise when the train is approaching and drop as...
Read More
How Does an Anchor Hold a Ship?
How Does an Anchor Hold a Ship? The weight of a simple cement-can anchor can keep a fisherman’s small boat from drifting away. The iron anchors of ships have flukes...
Read More
What Does a Sawfish Use Its Saw for?
The rostrum, often referred to as the “saw”, is used during feeding and for defense. The long, saw-like snout of a sawfish is used to attack other fish for...
Read More
How Does a Zipper Work?
How Does a Zipper Work? A zipper, zip, fly or zip fastener, formerly known as a clasp locker, is a commonly used device for binding the edges of an opening of fabric or...
Read More
When Were Traffic Lights First Used?
When Were Traffic Lights First Used? You may think that the familiar red-green, traffic signal is a product of the automotive age. But actually, the first traffic...
Read More