the.com/quaternion
The math that lets you rotate in 3D without gimbal lock ruining your day.
means A four-part number system (one real part, three imaginary) used to represent rotations in three-dimensional space cleanly and without the flips that plague simpler methods.
from From Latin 'quaternio,' meaning a group of four, built on 'quattuor' (four). The word drifted through English meaning any set of four things before mathematician William Rowan Hamilton seized it in the 1840s for his new four-term numbers (a + bi + cj + dk). Legend has it the core formula struck him mid-walk along a Dublin canal, and he carved it into the stone of Broom Bridge on the spot — a story that's well documented, unlike most mathematical eureka tales.
- invented by
- Hamilton, carved into a bridge in 1843
- structure
- one real part, three imaginary parts
- used in
- video games, robotics, spacecraft orientation
- weird property
- i squared equals j squared equals k squared equals ijk