Electricity

Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to electromagnetism.

Electricity is at the heart of Type 0 technologies, being used for:


 * Electric power where electric current is used to energize equipment.
 * Electronics which deals with electrical circuits that involve active electrical components such as vacuum tubes, transistors, diodes and integrated circuits.

The rapid expansion in electrical technology becomes a driving force for the Second Industrial Revolution.

History
In 1600 William Gilbert coined the Latin word electricus to refer to the property of attracting small objects after being rubbed. This gave rise to the words "electric" and "electricity".

In the 18th century Benjamin Franklin conducted extensive research in electricity, and in a famous experiment flew a kite in a storm-threatened sky. A succession of sparks jumping from the key to the back of his hand showed that lightning was indeed electrical in nature. He also explained the behavior of the Leyden jar as a device for storing static and electrical charge. In 1791 Luigi Galvani published bioelectromagnetics, demonstrating that electricity was the medium by which neurons passed signals to the muscles. Alessandro Volta's battery, or voltaic pile, of 1800, provided the world with a reliable source of electrical energy.

The recognition of electromagnetism, the unity of electric and magnetic phenomena, is due to Hans Christian Ørsted and André-Marie Ampère in 1819–1820. Michael Faraday’s contribution was that of electromagnetic induction in the 1820s. He noticed that when he moved a magnet through a stationary coil of wire, he always produced an electric current in the wire. This led him on to invent the electric motor.

Georg Ohm mathematically analyzed the electrical circuit in 1827 with the law of V=IR. Electricity and magnetism (and light) were definitively linked by James Clerk Maxwell from 1861. He suggested that changing the magnetic flux produced an electric field that not only caused electrons to flow in a nearby wire, but that the field also existed in space, even in the absence of electric charges. Maxwell expressed the change in magnetic flux and its relation to the induced electromotive force.

The late 19th century would see progress in electrical engineering through people such as Alexander Graham Bell, Thomas Edison, and Nikola Tesla, turning electricity from a scientific curiosity into an essential tool for modern life.

In 1887, Heinrich Hertz discovered that electrodes illuminated with ultraviolet light create electric sparks more easily.

Albert Einstein's discovery of the photoelectric effect is also employed in photocells such as can be found in solar panels and this is used to make electricity commercially.

In the modern world, electricity and electronics are so ubiquitous that they are concealed in households and in devices that we take for granted.