SINGAPORE: 13 February is World Radio Day, a day to celebrate radio as a medium; to improve international cooperation between broadcasters; and to encourage major networks and community radio alike to promote access to information and freedom of expression over the airwaves. As radio continues to evolve in the digital age, it remains the medium that reaches the widest audience worldwide.
Radio impossible without science!!!
Radio is the wireless transmission of signals through free space by electromagnetic radiation of a frequency significantly below that of visible light, in the radio frequency range, from about 30 kHz to 300 GHz. These radio waves travel by means of oscillating electromagnetic fields that pass through the air and the vacuum of space.
Information (sound) is carried by systematically changing some property of the radiated waves, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.
Radio electromagnetic waves are used because they can travel very large distances through the atmosphere without being greatly attenuated due to scattering or absorption. Radio receives the radio waves, decodes this information, and uses a speaker to change it back into a sound wave.
(C) Wikipedia.
The electronic signals transmitted to electromagnetic wave, chemistry has a role to play
In the above image, the electronic signals are transmitted to electromagnetic wave with the help of electronic processors. The electronic processors are usually semiconductors. These semiconductors (also known as computer chips, microchips, or integrated chips) are the miniature but powerful brains of high technology equipment. Semiconductor chips and transistors are created with silicon.
Silicon is a very common element, the main element in sand and quartz. In periodic table, silicon sits next to aluminum, below carbon and above germanium. Carbon, silicon and germanium have a unique property in their electron structure - each has four electrons in its outer orbital. This allows them to form nice crystals. The four electrons form perfect covalent bonds with four neighbouring atoms, creating a lattice. The conductivity of the semiconductor can be changed by a process called doping.
Another compound, tetramethylammonium hydroxide is used in the manufacture of integrated circuits, liquid crystal displays, printed circuit boards, capacitors, sensors, and many other electronic components. Tetramethylammonium hydroxide is non-metal containing, leaves no residual on heating and features exceptionally low contaminant levels.
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