Meditation on Infinite 5-dimensional Space

When we view the Sefirot as being ten directions in a five-dimensional continuum, we can also interpret this in the following manner. Each pair of Sefirot defines an infinite line, extended infinitely in both directions. The end points of such an infinite line, however, come together and meet once again at the "point in infinity." This is a fact recognized by mathematicians, and considerable use of the "point at infinity" is found in complex analysis, the calculus of complex numbers.

One can use this as a meditation. Try to imagine the sphere at infinity and the point at infinity, and attempt to perceive how they are actually one. You will then see that your usual conceptions of space and extension are not as simple as you believe.

(Sefer Yetzirah, R. A. Kaplan Commentary)