Wednesday, February 22, 2012

Happy Birthday Heinrich Hertz

Happy Birthday Heinrich Hertz

February 22, 1857 – January 1, 1894

A pioneer of radio signals and as a consequence the future of radio, all that is possible for wireless originates from the early discovery made by Heinrich Rudolf Hertz ( in proving the existence of radio waves. His pioneering works made reality that which was theorised of James Clerk Maxwell ( discoveries, commonly referred to as Maxwell's Equations how electric charges and electric currents act as sources for the electric and magnetic fields by defining a series of equations for electromagnetism. In science lessons, apart from being reminded that radio waves are analogue in nature, sometimes lecturers may visually demonstrate the forces of electric and magnetic fields using the hand reference: thumb, index finger and middle finger. The thumb represents a active 'source', the index finger represents 'electric field' and the middle finger represents 'magnetic field' at right angles to the electric field.

Hertz demonstrated the existence of radio waves in experiements using two rods that served as a receiver and also a spark gap as the receiving antennae, so that where radio waves were detected a spark would jump, demonstrating radio signals possessed the properties of electromagnetic waves. Moreover, his work is attributed to identifying that radio waves have (i) a 'time' factor and (ii) that the velocity of radio waves was equal to the velocity of light.  Hertz experiements revealed to him how to separate (thus detach) electric and magentic fields from wires and roam in free space; or as Maxwell is attributed to have put it the 'ethereal wind'. 

The unit of frequency of a radio wave is referenced as 'one cycle per second' and is named the 'hertz'.

Digital Signalling Background

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