what i know on this topic

1. radio
BY
MAEGHA SUBRAMANIAM

2. WHO INVENTED THE CONCEPT OF
MASS COMMUNICATION
Mass media refers collectively to all media technologies that are intended to reach a large audience via
mass communication. Broadcast media (also known as electronic media) transmit their information
electronically and comprise of television, film and radio, movies, CDs, DVDs and some other gadgets like
cameras or video consoles. Alternatively, print media uses a physical object as a means of sending their
information, such as a newspaper, magazines, brochures, newsletters, books, leaflets and pamphlets.
Photography can also be included under this subheading as it is a medium which communicated through
visual representations.[1][2] The term also refers to the organizations which control these
technologies, such as television stations or publishing companies.[3][4] Mobile phones, computers and
Internet are sometimes referred to as New-age Media. Internet media is able to achieve mass media
status in its own right, due to the many mass media services it provides, such as
email, websites, blogging, Internet and TV. For this reason, many mass media outlets have a presence on
the web, by such things as having TV ads which link to a website, or having games in their sites to entice
gamers to visit their website. In this way, they can utilize the easy accessibility that the internet has, and
the outreach that internet affords, as information can easily be broadcast to many different regions of
the world simultaneously and cost-efficiently. Outdoor media is a form of mass media which comprises
billboards, signs, placards placed inside and outside of commercial buildings/objects like
shops/buses, flying billboards (signs in tow of airplanes), blimps, and skywriting.[5] Public speaking and
event organizing can also be considered as a form of mass media.[1

3. WHAT IS RADIO
Radio is the transmission of signals through free space by
modulation of electromagnetic waves with frequencies
significantly below those of visible light.[1] Electromagnetic
radiation travels by means of oscillating electromagnetic fields
that pass through the air and the vacuum of space.
Information is carried by systematically changing (modulating)
some property of the radiated waves, such as
amplitude, frequency, phase, or pulse width. When radio waves
pass through an electrical conductor, the oscillating fields induce
an alternating current in the conductor. This can be detected
and transformed into sound or other signals that carry
information

4. WHEN WAS IT INVENTED
In 1855 provided the first demonstration of wireless
communication, and then in 1895 Guglielmo Marconi sent the first
radio signal. Radio developed from wireless telegraphy towards the
end of the 19th century. Spark transmitters made a crackling noise
in the receiver, speech and music was not possible. When
thermionic tubes became available in the early 20th century it was
now possible to modulated the transmitter current via the output of
a carbon granule microphone. In about 2001 radio operators were
stunned to hear the voice of an arctic explorer stating that he had
'found the pole' coming through their headphones where
previously there had only bcode tones. hello my name mustapha.hi
Read more:
http://wiki.answers.com/Q/When_was_the_radio_invented#ixzz1nr9
PYVDH

5. WHY WAS IT INVENTED
Within the history of radio, several people were involved in
the invention of radio and there were many key inventions
in what would eventually become modern wireless
communication systems.[1][2][3] Radio development
began as "wireless telegraphy".[1][4] During the early
development of wireless technology, and continuing long
after its widespread adoption, disputes persisted as to
who could claim credit for the invention of radio. The
matter was important for economic, political and
nationalistic reasons.