文字的幾何思考

多維空間 hyperspace 的思考

René Descartes: cogito, ergo sum (I think, therefore I am), which is based upon his idea that the mind and body are separate from each other. The mind, he said, is immaterial and non-extended... By non-extended he meant that it doesn't exist in three dimensional space. The body, along with other matter, does exist in three dimensional space. This hints at one of Descartes' chief concerns in life - geometry. He devised the system to identify a point in 2 D space.. (Figure) ...the two axes make up what is known as a two dimensional Cartesian coordinate system, the word Cartesian meaning related to Descartes.

The 2D Cartesian coordinate system can be extended into 3D by adding a third axis, z. ....Moving point (5,7,3) up the x axis by three units changes the point to (8,7,3); the 7 and the 3 remain constant. The dimensions are said to be orthogonal to each other.