According to a recent study of Nobel Prize winners, researchers Bruce Weinberg of Ohio State University and Benjamin Jones of Northwestern University have determined that major scientific contributions tend to be made more frequently by older scientists than by younger scientists.   Prior to the twentieth century, two-thirds of Nobel laureates did their prize-winning work before the age of forty.  But by the beginning of the twenty-first century, great achievements seldom occurred before the age of forty.  Einstein, who did his landmark work while in his twenties, is now the exception rather than the rule.  Accounting for the shift, Weinberg and Jones explain that as time goes by there is simply much more to learn since advances in the field have multiplies over the last century.  Moreover, practical discoveries require much more painstaking work than theoretical proposition.  And lab work requires time.  The implication is clear: as more and more sources become part of the Jewish tradition, it is unlikely that we will see rabbinic prodigies who can master the full spectrum of the Jewish tradition.  Notoriety in the field will come to scholars who spend years immersed in learning.