Audio Equipment and Home Theater Audio : How does a radio use energy?

How does a radio use energy?

In the nineteenth century, Scottish physicist James Clerk Maxwell (1831–1879) developed a mathematical theory proving that magnetism and electricity were related. His theory linking the two forces became known as the electromagnetic theory.

He predicted that light is only one type of electromagnetic radiation and that wavelengths should exist below infrared (those situated outside the visible spectrum at the red or long-wavelength end) and above ultraviolet (situated outside the visible spectrum at the violet or short-wavelength end). In the 1880s, German physicist Heinrich Hertz (1857–1894) discovered extremely long-wavelength radio waves, proving Maxwell's theory.

Although turning on a radio produces sound, radio waves themselves cannot be "heard" and have nothing to do with sound waves. While sound waves are a vibration of the air, radio waves are electromagnetic and a part of the light spectrum. Radio waves travel at a speed of 186,282 miles (299,727 kilometers) per second—the speed of light. Radio waves travel through the air, surrounding us with vibrations that can only be detected through a radio receiver.

Radio programs begin as sound waves, which microphones change into electrical signals. From the antenna atop the radio station, the electrical signals are broadcast as electromagnetic waves. The receiver picks up the waves in the air, electrically amplifies (enlarges) them, and converts them back into sound through the speaker of the radio in your home.

Although radio waves from many stations surround us all the time, the radio does not receive them all at the same time because the stations broadcast at different frequencies. A frequency is the number of times per second that radio waves vibrate. The numbers on a radio dial represent the frequencies used by radio stations in your area. For example, if the dial is set at 96, the radio signal you hear is broadcasted at 960 kilocycles, or 960,000 cycles per second.

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About Elon Musk

In April, Neuralink released a video of a monkey playing a video game using one of the company’s devices. At first, the monkey is physically moving a joystick, while the microchip records its brain activity. When the joystick is unplugged, the monkey is still able to control the game via brain signals being relayed by the Neuralink chip. As Musk tweeted at the time, the chip should theoretically “enable someone with paralysis to use a smartphone with their mind”.

In July last year, Musk announced that he was working on a microchip that would allow wearers to stream music directly into their brains – it’s unclear if this is the same device.

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