Guglielmo Marconi lived from 1874 till 1937. He developed a way of "wireless" communication. He found that you could use radio waves as a signaling system. Marconi discovered that a circuit carrying an electric current that rapidly alternates direction produces radio waves.

             The sound wave is a type of compression or longitudinal wave. In a .

             compression or longitudinal wave the vibrations happen in the same direction as the .

             wave"s velocity. A compression or longitudinal wave looks like this:.

             1) Areas of compression (high pressure), 2) areas of rarefaction (less pressure), 3) the wavelength, 4) the direction of the velocity.

             Waves have to have to have a medium to travel through and travel best through solids. Waves are a way to transfer energy from one place to another.

             The frequency is the length of one cycle of a wave. The frequency determines the pitch of the wave"s vibrations that you hear. Frequency is the velocity of the wave divided by the wavelength. The wavelength is the distance from the center of a wave"s crest to the center of the next crest. Velocity is the speed of something in a certain direction. The frequency of the carrier signal is about 100 million waves per second, known also as 100 Megahertz (100 MHz). .

             The amplitude determines the loudness. The amplitude is when the signal goes through an amplifier, which makes the signal louder and stronger. Radio waves move 186,000 miles per second.

             Marconi started experimenting with sound waves in 1896. Two years later he invented and patented the Oscillating Sintonic Circuit with inductance and capacity. .

             This made it possible to send and receive messages. It also made it so that more than one station could be installed in the same place. Before the Oscillating Sintonic.

             Circuit, it wasn"t possible to receive more than one station in the same place, because the transmissions of stations would interfere with each other. Another problem was that you couldn"t even select the signal on reception.