Before I forget: there's a moment in life of a category when functions have to become functors, and vice versa. We can think about it as if an object is being "expelled" from its mother category and has to become its own category. Alternatively, a category can be "sucked" into another category and become an object. (the video below describes how ( Read more... )

The [Roman] empire is a constant presence in our evidence from this period, and it enters mathematical discourse in several ways. Managing an army, collecting taxes, keeping a census on such a vast scale implied centralized administrative practices (accounts, tax rolls, land surveys). Mathematics was also used to articulate views about politics, ( Read more... )

Although estimates vary, military history experts generally agree that the average GI who served in Europe from D day to the end of the war had sex with about twenty-five women. By the time Germany surrendered, the US occupying army had to ration condoms to four per soldier per month, something an army official complained was “entirely inadequate ( Read more... )

The merchants of Amsterdam at the end of the ixteenth century-a hundred years after the great flow f silver had started-were the recipients of a notably diverse collection of coins, extensively debased as to gold or silver content in various innovative ways. A manual for money changers issued by the Dutch parliatnent in 1606 listed 341 silver and ( Read more... )

Human nature lay be an infinitely variant thing. But it has constants. )ne is that, given a choice, people keep what is the ,est for themselves, i.e., for those whom they love be most ( Read more... )