I mentioned earlier the fact that Jenkin’s article raised a few other objections to Darwin’s theory of evolution. In particular, Jenkin relied on calculations by his friend and partner the famous physicist William Thomson (later Lord Kelvin), which appeared to show that the age of the Earth was much shorter than the vast expanses of time Darwin needed for his theory of evolution to work. The ensuing controversy provides us with fascinating insights not only into the differences between the methodologies in various branches of science but also (admittedly much more speculatively) into the operation of the human mind.

In the Beginning, God created Heaven and Earth . . . Which beginning of time, according to our chronology, fell upon the entrance of the night preceding the twenty-third day of October in the year of the Julian period, 710.

—JAMES USSHER, 1658

Humans have been curious about the age of the Earth since recorded history. It is not often the case, after all, that one number—the Earth’s age—can have important implications for such diverse fields as theology, geology, biology, and astrophysics. Given that each one of these different disciplines has had its share of strongly opinionated individuals, we shouldn’t be too surprised to discover that by the nineteenth century, the attempts to estimate the Earth’s age had led to a number of bitter controversies.