Home▸Physics & Mechanics▸The Millikan Oil Drop Experiment: Measuring the Charge of a Single Electron

🛢️ The Millikan Oil Drop Experiment: Measuring the Charge of a Single Electron

Explore how Robert Millikan's 1909 oil drop experiment measured the elementary electric charge and proved that charge is quantized, with an interactive simulation of the apparatus and a worked numeric example.

Physics & Mechanics3DModerate60 FPS⚡ Plasma

This simulation demonstrates how an electric field can be tuned to exactly balance gravity on a charged oil droplet, and how measuring that balance reveals the droplet's quantized electric charge.

🔬 What It Demonstrates

This simulation demonstrates how an electric field can be tuned to exactly balance gravity on a charged oil droplet, and how measuring that balance reveals the droplet's quantized electric charge.

🎮 How to Use

Adjust the voltage across the plates to make the droplet hang suspended or drift at a steady speed, then compare the calculated charge against multiples of the elementary charge.

💡 Did You Know?

Millikan and Fletcher measured over a thousand oil droplets, and every single one carried a charge that was a whole-number multiple of the same tiny elementary charge.

⚙ Under the hood

physicsmillikanelectron chargequantum physicselectromagnetismhistory of scienceatomic physicselectric field

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install