I was reading Quaternions and Rotation Sequences.
The second paragraph says:
Historians of mathematics are generally agreed that…three highly significant developments occurred during the nineteenth century. These were:
- the development of non-Euclidean geomery,
- [the development] of a non-commutative algebra,
- and [the development] of a precise theoretical foundation for calculus.
Wait a minute . . . WTF is “Euclidean Geometry”, exactly? At first blush, I didn’t recognize that Euclidean Geometry is really what you learned in high school. They never call it that though! They just call it ‘algebra’. I can’t believe I didn’t actually know (or remember . . . ? ) that Euclidean Geometry __IS__ what fills algebra texts in schools today.
What of the original text from which Euclidean Geometry comes from? Still exists. Not read today by most, though. From Wikipedia: