ThinkBlog

I was relieved to find that the GRE (the grad-equivalent of the SAT—it’s even by the same people!) has only sixth-through-ninth-grade maths on it; but in my review of some old concepts, I stumbled across factorials, which I last dealt with in programming recursive methods that would take a value and return its factorial only after a memory-and-proc-intensive computation. The factorial of any number is defined as that number times one less than it, times one less, and so forth, all the way down to 1: or, 1 times 2 times 3 and so on until we get to the number itself. Hence, Five factorial (written “5!”) equals 120, because 5*4*3*2*1==120.

But what about 0! ? Prima facie it makes sense that 0! would be 0, because 0*1==0, but it’s not. There is an explanation (which for the curious can be found here) as to why 0!==1, but I think we can all agree it doesn’t seem immediately intuitive.

This provides a funny, perhaps ridiculous, yet telling illustration of Creation. God created ex nihilo Being, i.e., all that exists, by speaking. If we may exercise a bit of comedic license, we can say that God shouted (!) at zero (nothingness) and 1 (Being) was the result; and at first it doesn’t make intuitive sense, but if we know the underlying algorithym (God’s character) everything just falls right into place.

I was relieved to find that the GRE (the grad-equivalent of the SAT—it’s even by the same people!) has only sixth-through-ninth-grade maths on it; but in my review of some old concepts, I stumbled across factorials, which I last dealt with in programming recursive methods that would take a value and return its factorial only after a memory-and-proc-intensive computation. The factorial of any number is defined as that number times one less than it, times one less, and so forth, all the way down to 1: or, 1 times 2 times 3 and so on until we get to the number itself. Hence, Five factorial (written “5!”) equals 120, because 5*4*3*2*1==120.

But what about 0! ? Prima facie it makes sense that 0! would be 0, because 0*1==0, but it’s not. There is an explanation (which for the curious can be found here) as to why 0!==1, but I think we can all agree it doesn’t seem immediately intuitive.

This provides a funny, perhaps ridiculous, yet telling illustration of Creation. God created ex nihilo Being, i.e., all that exists, by speaking. If we may exercise a bit of comedic license, we can say that God shouted (!) at zero (nothingness) and 1 (Being) was the result; and at first it doesn’t make intuitive sense, but if we know the underlying algorithym (God’s character) everything just falls right into place.