3-sphere two 3-balls. This construction is analogous to a construction of a 2-sphere, performed by gluing the boundaries of a pair of disks. A disk is a 2-ball, and the boundary of a disk is a circle (a 1-sphere). Let a pair of disks be of the same diameter. Superpose them and glue corresponding points on their boundaries. Again one may think of the third dimension as temperature. Likewise, we may inflate the 2-sphere, moving the pair of disks to become the northern and southern hemispheres. After removing a single point from the 2-sphere, what remains is homeomorphic to the Euclidean
Core sphere approximately 30% of the total product. Long before the Industrial Revolution, the core sphere was the entire economy. Families and communities provided for themselves by hunting and gathering. Then with industrialization came a market of competitive men working for wages and along with it what historians call the cult of domesticity. The core sphere became regarded not as part of the market sphere of the economy but more as emotional and altruistic behavior. Therefore, activities in the core sphere were not considered economic because they do not directly influence the market economy. As time has progressed towards the present, organizations