Z G07: Sciences Light & Sound: Cell phones

A generation ago, people needed a quarter for a payphone or used rotary dial at home. Mobile phones make it easier to meet up with friends. Smartphones allow you to surf the Web or play a game while waiting in line. Watch people panic if their battery dies or their phone malfunctions. Today's gadgets offer constant stimuli, making it difficult to focus. Your boss can contact you anytime and anywhere. Horror films now have to explain why the characters aren't getting a signal....

A portable telecommunications system, a cellular telephone is a mobile radio transmitter liked to a base station through microwave radio frequencies. The network consists of many geographic cells, each with a base station and assigned frequencies. A computer switching system is used to transfer a call to a new base station as the caller travels. In 1979, the first cellular system was used in Tokyo, and then four years later in Chicago. Cellular phones today may contain cameras, alarm clocks, calculators, and Internet browsers.

Did you know that cellular telephones are two-way radios to a cell tower? From there, they are connected to regular telephone lines. Did you know that a cell phone turns your voice into a form of electricity? Call phones allow people to communicate from their car, the mall, or the beach, as long as they are close enough to a tower. Like an antenna, the tower picks up the signal to transmit your message. Did you know the first cell phones were invented in 1973 and weighed two pounds?

Take a look at the history of the cell phone as it celebrated its fortieth birthday in 2013. This article tells you about the first cell phone that made a call in 1973 and it tells you about the history of the landline telephone. You will also learn how cell phones have changed over the years and come a long way since the first brick cell phones. Information on the future of cell phones is provided as well.

Cell phones have enabled users to be connected to others every minute of the day. In third world countries where landline networks never quite got off the ground, cell phone technology blew right past it. Cell phones use electromagnetic radio waves rather than cables. A tiny microphone in the device converts your voice to electric signals; a microchip turns the signals into series of numbers, which the phone’s antenna sends it through the air to the nearest cellphone tower.

If you couldn't see, how could you use a computer or cell phone? In today's digital society, people use devices to communicate and learn. People who are visually impaired need assistive technology to use computers. They might use a screen reader, magnification, or braille display to read what's on the screen or in a book. Textbooks are available in braille or audio books. Other technologies take the place of a mouse and cursor. Learn about how people who are visually impaired text and navigate on a cell phone.

Explains the different parts of a cellular system.

Many devices you probably use every day are made possible by the electromagnetic spectrum. Some examples of these useful items are radios, cell phones, and microwave ovens. The scientists at the National Aeronautics and Space Administration, or NASA, invite you to visit their colorful, informative web site to uncover the facts about these essential, yet sometimes invisible, waves.