Microwaves are invisible rays of electromagnetic energy that travel at the speed of light(186,282 miles per second). Microwaves used in microwave ovens are in the same family of frequencies as the signals used in radio and television brodcasting.
To fully understand what a microwave is you must know what the properties of an elecromagnetic energy is. What exactly is electromagnetic energy you ask? This theory is very hard to explain. The best analogy could be when a pebble is tossed into a quiet pond. The pebble striking the still surface causes the water to move up and down in the form of ripples, or waves, that radiate in circles over the surface of the pond. These waves, which move up and down at right angles to the direction in which they are traveling are called transverse waves. Microwaves are examples of these. Another analogy is one that we did in class, with the slinky.
This disturbance resulting from the pebble landing in the water is transmitted through the water in the form of ripples or waves. In a sense, these ripples are more like sound waves, normally using the molecules in the air or water.
But, electromagnetic forms of energy travel throught the emptiness of space without the need of any material medium through which to travel. This is because electromagnetic waves are stored energy in motion.
Frequency Spectrum
Mircowaves fall in the area of radar, and TV,on the frequency spectrum, which is non-ionizing radiation. What is ionizing radiation? Well, ionizing radiation is extremely high in frequency, therefore it is very powerful and penetrating. Even at low levels ionizing radiation can damage the cells of living tissue. In fact, these dangerous rays, have enough energy and intensity to actually change the molecular structure of matter, or genetic mutations. As shown on the frequency spectrum, the ionizing range of frequencies includes X-rays, gamma rays, and cosmic rays.
Non-ionizing radiation is very different. Because of the lower frequency and reduced energy it does not have the same damaging and cumulative properties as ionizing radiation.
Copyright @1998 Matt Fields