Earliest records show a spoon shaped compass made of lodestone or magnetite ore, referred to as a "South-pointer" dating back to sometime during the Han Dynasty (2nd century BCE to 2nd century CE).

Follow the orange icon on your compass until you reach the outer wall of the Sphere that spans all around the enormous structure. Once you're here, begin moving around the right-hand side on the ...

The Sphere function has d local minima except for the global one. It is continuous, convex and unimodal. The plot shows its two-dimensional form. The function is usually evaluated on the hypercube x i ...