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Radiophysics (also modern writing radio physics [1]) is a branch of physics focused on the theoretical and experimental study of certain kinds of radiation, its emission, propagation and interaction with matter. The term is used in the following major meanings: study of radio waves (the original area of research) study of radiation used in ...
Gregory the Great: "Miracles also were granted to the holy preachers, that the power they should show might be a pledge of the truth of their words, and they who preached new things should also do new things; wherefore it follows, Heal the sick, raise the dead, cleanse the lepers, cast out dæmons."
Radio waves are more widely used for communication than other electromagnetic waves mainly because of their desirable propagation properties, stemming from their large wavelength. [13] Radio waves have the ability to pass through the atmosphere in any weather, foliage, and through most building materials.
The radio waves carry the information across space to a receiver, where they are received by an antenna and the information extracted by demodulation in the receiver. Radio waves are also used for navigation in systems like Global Positioning System (GPS) and navigational beacons, and locating distant objects in radiolocation and radar.
Radio-frequency (RF) engineering is a subset of electrical engineering involving the application of transmission line, waveguide, antenna, radar, and electromagnetic field principles to the design and application of devices that produce or use signals within the radio band, the frequency range of about 20 kHz up to 300 GHz. [1] [2] [3]
Symbol for radio waves . Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by certain astronomical objects.
The effects of electromagnetic radiation upon living cells, including those in humans, depends upon the radiation's power and frequency. For low-frequency radiation (radio waves to near ultraviolet) the best-understood effects are those due to radiation power alone, acting through heating when radiation is absorbed.
These waves travel in vacuum at the speed of light and exist in a wide spectrum of wavelengths. Examples of the dynamic fields of electromagnetic radiation (in order of increasing frequency): radio waves , microwaves , light ( infrared , visible light and ultraviolet ), x-rays and gamma rays .