As is the case with many other areas of the modern world, medical science has made enormous strides over the past century or so, and it seems as though the pace of change is accelerating. It’s like being with Edwin Hubble and Georges Lemaître when they first started looking at far-flung regions of the universe. They both realized the universe was expanding, but what was not immediately obvious was that the expansion was accelerating. To me, that’s where things stand with medical science now, and while the chatter about telomerase has...