A laser is a thin beam of light. People use lasers all the time. You may have a laser at home. A DVD player uses a laser to read a DVD. A cashier uses a laser to read bar codes.
Photo Credit: ktsdesign/Shutterstock
In the Know
The First Hot Air Balloon Flight
People have always dreamed of flying. How did engineers first … read more
In the Know
The Super Bowl
Every year there is a special football game. It is … read more
In the Know
Taking a Car Trip
It’s almost summer. Many people take car trips during the … read more