Millikan oil-drop experiment

• In 1910, Millikan succeeded in measuring the electron charge for the first time with a very sensitive experiment.
• In this experiment, electrically charged oil droplets remained suspended in the air under the influence of a force that balanced the electric field applied between the plates of a capacitor and the gravitational force.
• From the equation $qV/d=mg$, the electric charge of each droplet could be calculated by measuring the potential difference and masses.
• When Millikan listed these electric charges from smallest to largest, he showed that they were multiples of a basic unit of charge, and from there he determined the electric charge as $e = 1.65 \times 10^{-9}~C$ (Today's value is $e = 1.602 \times 10^{-9}~C$).

Example py-file: Millikan oil-drop experiment by Least-Square Approximation. Gaussian elimination & back substitution. Pivoting. mylsa_millikan.py

Figure 7.11: Millikan oil-drop experiment.