An induction coil connected to the spheres caused a spark to jump across the gap, producing oscillating currents in the rods. Hertz built a transmitter for such waves consisting of two flat, square metallic plates, each attached to a rod, with the rods in turn connected to metal spheres spaced close together. This would prove that visible light is only one example of a larger class of electromagnetic effects that could pass through air (or empty space) as a succession of waves. During the late 1880s he carried out a landmark experiment to test the theory of the British mathematician-physicist James Clerk Maxwell. The first antenna was devised by the German physicist Heinrich Hertz. The speed at which both forms of waves travel is the same they both travel at the speed of light. Although they can neither be seen nor felt, their presence can be detected through the use of sensitive measuring devices. Radio waves are a form of radiant energy, similar to light and heat. They can also be focused (concentrated) like the flashlight, depending upon the need. Like the light in the room, radio waves may spread out in all directions. You can use these examples to picture how radio waves propagate. When a flashlight is turned on, light rays also radiate from its bulb, but are focused into a narrow beam. When a light is turned on in a darkened room, light rays travel from the light bulb throughout the room. Radio waves are propagated, which means "moved through a medium." This is most easily observed by light rays. For instance, we can see light, hear sound, and feel heat. Some of these waves stimulate our senses and can be seen, felt, or heard. So what is it exactly that these sometimes oddly shaped devices do in the overall big scheme of radio transmission and reception?Īll things on the earth, in the water, or even in the air are showered continually with waves of energy. To facilitate air to ground and ground to air or even air to air voice and data transmission an array of antennas are strategically placed on the airframe. The information age is truly upon us and even our aircraft have a need to know what's going on. Commercial aviation only became a reality after the introduction of radio navigation. Adaptation of the magnetic compass and development of the gyroscope were pivotal components in promotion of maneuvering when outside vision was impaired. Once upon a time aircraft were only operated when the pilot had a clear view of the ground and visual reference was the only means of navigation.
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