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first U.S. radio station
The KDKA was the first radio station. Now days we have a lot of stations in the radio. They all play different types of music but almost everyone listens to them all over the world. -
lie detector
Invented by John A. Larson
The lie detector or in other words the polygraph was invented to check on a person's blood or nervousness when they were being interrogated. According to my reading polygraphs machine are not really reliable. Some states do not allow lie detectors as evidence in courts. -
traffic signal
Invented by Garret Morgan
Before the traffic signal only had two positions but Morgan changed that and made it three which was called the t-shape pole. Today there are about 300,000 traffic lights in the U.S. Lights are such a good technology if we didn't have them there would probably be so many accidents and traffic. -
instant camera
Invented by Samuel Shlaflock
Back then the camera consisted of a camera and portable dark room in a single compartment. That was changed by Edwin land who created the one we know today. Cameras are a big thing now and their even more advance in different ways. -
television
Invented by John Logie Baird
Baird invention allowed people to see pictures or programs. Today everyone uses television specifically smart TV's. Adults and kids sometimes might spent long times in front of a tv. There's also a lot of streaming sites where you can watch nay type of show you want.