History of TV

History of TV
We often watch TV. We can watch it any time. It have many information. For example, the newest news, national information, show business news and so on. We enjoy watching TV evry time . But we only watch it. We do not know about TV. So I want to examine about TV history. And I want to know about TV mechanism and influence of audience.
TV is a widely used telecommunication system for broadcasting and receiving moving pictures and sound over a distance from all around the world. The term may also be used to refer specifically to a television set, programming or television transmission. The word is derived from mixed Latin and Greek roots, meaning.
Since it first became commercially available from the late 1930s, the television set has become a common household communications device in homes and institutions, particularly in the First World, as a source of entertainment and news. Since the 1970s, video recordings on VCR tapes and later, digital playback systems such as DVDs, have enabled the television to be used to view recorded movies and other program.
A television system may be made up of multiple components, so a screen which lacks an internal tuner to receive the broadcast signals is called a monitor rather than a television. A television may be built to receive different broadcast or video formats, such as high-definition television, commonly referred to as HDTV. HDTV costs more than normal TV but is becoming more available.
The basal ganglia portion of the brain becomes very active when a person plays video games and watches TV. And the body releases a chemical called dopamine. Ritalin (and cocaine) also works on the basal ganglia of the brain and increase dopamine. More dopamine is released; the less neurotransmitter is available to do anything else. For that reason persons with illnesses related to dopamine unbalance like ADHD should limit the time spent on watching TV to a half-hour a day.
Tv has many problems. But it has many convinient imfornation. We can study may things for very short time. And very fast imfomation coming us. It is very need things by our life. TV is revolution of invention in this human life.
<340words>