How with a detailed description are EM waves such as radio waves actually created?

Answer 1

When a source of energy causes the medium to vibrate. --------------- When an object experiences a change in its electric charge, the strength of its magnetic field also changes. These changes radiate outward. In the case of radio waves, the fluctuating changes are usually considered to occur at regular intervals and intensity, as in so many cycles per second, and with a certain level of strength at any given distance. The speed of the radiating effect is at the speed of light, and the strength diminishes exponentially as the distance increases. I.e., the strength of the fluctuation at one meter will be the strength of the fluctuation at two meters, squared. A unique example of this, in the form of a single pulse, is lightning. Lightning produces a single fluctuation, with its rate of change VARYING across the entire frequency spectrum, hence the color is generally a bluish white in the visible spectrum. The associated heat in the infra-red spectrum causes the surrounding air to expand at super-sonic speed, producing a sonic boom. In the frequency spectrum of radio waves, the pulse will produce a static noise click on your radio receiver, regardless of the frequency your receiver is tuned, as the pulse covers the entire energy spectrum. Multiple clicks may be heard, as caused by echoes from other objects struck by the initial pulse. There are multiple factors contributing to a lightning pulse, and in the case of storm clouds, a lightning discharge can happen at long distances, several miles away from the storm in fact. Some of the factors that determine when/where lightning might strike are now thought to originate out in space, in addition to proximity, conductivity and gravity on the surface.