Short Timeline of the birth of Electrical Engineering

In Electrical Engineering there are many many formulas that came from people doing experiments and determining them. Wikipedia has a historical but it is not complete and a lot of things (like Lenz) are mentioned https://en.wikipedia.org/wiki/Timeline_of_electrical_and_electronic_engineering.

Here I attempt to make a timeline from the point of view of the formulas or famous methods and when they were derived:

• 174x Andrew Gordon and Benjamin Franklin develop the first electric motors
• 1799 Alessandro Volta invents the voltaic pile (a battery) and produced the first steady electric current.
• 1820 André-Marie Ampère formulates Ampere's Law. theorizes the "electrodynamic molecule", or the electron.

\[\frac{F_m}{L} = 2k_A\frac{I_1 I_2}{r}\]

• 1826 Georg Simon Ohm discovers relationship between voltage and current, resistance and its relationship to the dimensions of the conductor

\[R = \frac{V}{I}\]

• 1828 George Green discovers Green's theorem

• 1831 Joseph Henry discovers self-inductance

\[v(t) = L\frac{di}{dt} \]

• 1831 Michael Faraday and Joseph Henry discover mutual-inductance

\[\frac{V_p}{V_s} = \frac{N_p}{N_s} \]

• 1832 Michael Faraday builds the first electric generator

• 1834 Heinrich Lenz formulates Lenz's law:

\[EMF = -\frac{d\Phi}{dt}\]

• 1835 Prof. William Thomson (a.k.a) Lord Kelvin wrote about capacitance. It is not clear how Q=CV came about but this publication in the Journal of Science seems to be the closest.

\[i(t) = C(\frac{dv}{dt}) \]

• 1845 Gustav Kirchoff announced Kirchoff's Laws.

\[\sum_{i=1}^{n} V_{i} = 0 (loop) \]

\[\sum_{i=1}^{n} I_{i} = 0 (node) \]

• 1850 Lord Kelvin and George Stokes invent Stokes' Theorem

• 1853 Hermann von Helmholtz derives Thevenin's Theorem

• 1853 Lord Kelvin showed that discharge between Leyden Jars and a self-inductive device should be oscillatory, and derived its resonant frequency.

\[f_0 = \frac{1}{2\pi \sqrt{LC}}\]

• 1862 James Clerk Maxwell publishes his famous laws, albeit not in their modern form shown here:

\[\nabla \cdot \textbf{E} = \frac{\rho}{\epsilon_0}\]

\[\nabla \cdot \textbf{B} = 0\]

\[\nabla \times \textbf{E} = -\frac{\partial\textbf{B}}{\partial t}\]

\[\nabla \cdot \textbf{B} = \mu_0(\textbf{J} + \epsilon_0\frac{\partial\textbf{E}}{\partial t})\]

• 1872 Lork Kelvin coins the term permeability, relating magnetic flux density to magnetic field

\[\textbf{B} = \mu \textbf{H} \]

• 1879 Walter Baily built the first AC induction motor

• 1880 Oliver Heaviside introduces electrical permittivity, relating displacement field to electric field

\[\textbf{D} = \epsilon \textbf{E} \]

• 1884 Oliver Heaviside calls the coefficient of self-induction, simply inductance
• 1884 John Henry Poynting derives the Poynting vector, showing the directional energy flux

\[\textbf{S} = \textbf{E} \times \textbf{H}\]

• 1898 John Ambrose Fleming publishes a book with the Left and Right hand rules of electromagnetism

• 1897 Sir Joseph John Thomson discovers the electron.

• 1926 Hans Ferdinand Mayer and Edward Lawry Norton derived Norton's Law

• 1971 Leon Chua theorizes the final fundamental component, the memristor

\[M(q) = \frac{d\phi_m}{dq}\]

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