[D]espite over 150 years of endeavor by the world’s greatest minds, the hunch that Riemann had in 1859, the same year that Darwin published On the Origin of Species, has not revealed the origins of what makes the primes tick. They are still part of the unknown. But I think all of the mathematicians that strive to prove this great theorem believe that it won’t remain unknown forever. But how can we be sure? How can we know that we will ultimately discover the answer. The unknown is the life blood of mathematics. The things we don’t know are what make it a living breathing subject not just a subject confined to the static journals on the library shelves of our great institutions. It is the unknown that thrills us as practicing mathematicians. But what if there is no proof. What if there are things that there is no way we can know. It is the unknowable that fills us with terror.