Microwaves are not only good for cooking food, Microwave towers like this were once used, prior to improvements in satellite technology, for communication.
The History of the Microwave
- The origin of the microwave started with James Maxwell Clark in 1864. In this year Clark developed a theory that light and a magnetic field could be combined and travel at the speed of light. His theory was later found to be true and was the start of electromagnetic waves, including radio waves.
- In 1886 a man named Henrich Hertz tested James Maxwell Clark's theory. By switching electrical current from high to low rapidly and transmitting the current through a conductive wire, Hertz was able to create waves we now call radio waves.
- In 1935 Robert Watson-Watt, experimented with higher frequency radio waves. These waves switched from high to low faster than most radio waves. His research led to Robert Watson-Watt invention and patent of radar.
- After World War II, microwaves and other radio wave frequencies were allowed by non-miliary companies in the United States. Western Union, American Telephone and Telegraph (AT&T), RCA, IBM, Raytheon and other companies began to look at the new technology for other uses. Starting in 1943 microwave communication towers were built by Western Union, AT&T and others. Western Union became the first company to send data in the form of a telegraph wirelessly. The microwave communication system allowed distribution of data by receiving and re-transmitting data through repeater towers spaced at 30 miles apart. The microwave technology allow line-of-site clean communication because of its narrow focused frequency.
- In 1946 an engineer with Raytheon named Dr. Percy Spencer accidently discovered that certain radar waves would heat foods. After further investigating he found that the radar magnetrons he was working with would heat anything with water. In 1954, the Amana company (a company founded by Raytheon) developed the first commercial microwave cooking oven.
- Microwave communication is used by NASA and other space agencies for deep space communiction. Since a microwave has a narrow, focused frequency band, it will travel in a straight line and can penetrate the Earth's atmosphere. Microwave communication is clear over a long distance through space.
- In 1959 U.S. Navy engineers discovered that microwaves could bounce off objects in the solar system. They were able to bounce a microwave communication from Washington D.C., off the moon, to a receiving in Hawaii.
- Microwaves are defined as radio waves with a wavelength in the range of 3,000 to 30,000 MHz.
- The Federal Communication Commision (FCC) in the U.S. set up a reserved microwave frequency of 2450 MHz.
- Microwave ovens use a magnetron to make microwaves that can heat and cook food.
- It is possible to transmit data using microwaves.
- Microwaves are almost always present on the Earth's surface. Scientists have discovered that there is a low-level of microwaves present under normal conditions, possibly because microwaves can easily enter the Earth's atmosphere.
Microwaves most well-known use is to heat things in a microwave oven.
NASA used microwaves to take this image of the Milky Way solar system over a time period of 1 year. Photo credit: nasa.gov