Radio Waves and Microwaves
Radio waves transmit information through modulation - changing a carrier wave to carry sound or data. There are two main types: AM (Amplitude Modulation), where the height of waves varies with the sound, and FM (Frequency Modulation), where the frequency changes to match the audio signal. Radio waves range from low frequencies 30−300kHz to ultra-high frequencies (up to 100,000 MHz).
Satellites orbiting Earth use radio waves for various purposes: communication (Comsat), weather tracking (Metsat), navigation (Navsat), scientific research, and Earth resource monitoring (Landsat). These applications have revolutionized how we communicate, navigate, and understand our planet.
Microwaves have shorter wavelengths than radio waves and serve multiple important functions. They power satellite communications by penetrating Earth's atmosphere, enable radar systems to detect objects by reflecting signals, and connect cell phone towers in terrestrial communications networks. Your microwave oven works because food absorbs certain microwave frequencies, converting them to heat.
Did You Know? Communication satellites orbit about 35,000 km above Earth's equator at speeds of 11,300 km/h, constantly receiving and transmitting microwave signals to keep us connected!
Infrared radiation sits between microwaves and visible light on the spectrum. Though invisible to our eyes, we can detect it as heat. All objects emit infrared radiation - cooler objects emit blue-green wavelengths, while warmer objects emit red-yellow wavelengths. This principle enables night vision goggles, remote controls, medical scanning, and specialized photography.