A world ocean

The most obvious way to explain this gap of 15,000 miles was to invoke the explanation that all geographers from antiquity down to Biruni’s day had accepted: that the Eurasian land mass was surrounded by a ‘World Ocean’. But was three fifths of the Earth’s circumference really nothing but water? Biruni considered this possibility but rejected it on the grounds of both observation and logic. From his study of specific gravity he knew that most solid minerals were heavier than water. Would so watery a world not give rise to serious imbalances to which the planet would have had to adjust over time? And why, he asked, would the forces that had given rise to land on two fifths of the earth’s belt not also have had an effect on the other three fifths as well? Biruni concluded that somewhere in the vast expanses of ocean between Europe and Asia there must be one or more unknown land masses or continents.

Were these unknown continents empty wildernesses or ones inhabited by human beings? To address this question Biruni turned to his data on longitudes. He noted that human beings inhabit a broad north-south band stretching from Russia to southern India and the heart of Africa. If the unknown continent or continents were uninhabited, he reasoned, they would have to lie either north or south of this band.

To pursue this hypothesis Biruni went beyond his field observations and employed Aristotelian logic, a reasoning process built from propositions. Noting that the Eurasian land mass stretched roughly around the Earth’s belt, he hypothesised that it must have been the result of powerful processes that would surely have obtained elsewhere. Known evidence of the Earth gave him no grounds for believing that the unknown continents would be squashed into the northernmost and southernmost latitudes. He concluded that the unknown land masses between the Atlantic and Pacific Oceans would have to be inhabitable as, in fact, they were.

Biruni reached these momentous conclusions about the existence of the New World by 1037, basing them on research he had conducted over the preceding three decades.

Did Biruni discover America in the first third of the 11th century? In one sense, definitely not. He never laid eyes on the New World or the continents about which he wrote. By contrast the Norsemen had actually touched land in North America shortly before ad 1000; briefly, to be sure, and without really understanding what they had found. Leif Ericson was so uninterested in the forested shore of North America that he did not bother to return later, nor did any of those who heard oral reports of Ericson’s travels or read about them in later Norse documents. Still, if ‘discovery’ includes the unreflective processes of Norse seafaring, then the prize must go to the Vikings.

Yet Biruni is at least as deserving of the title of North America’s discoverer as any Norseman. Moreover, the intellectual process by which he reached his conclusions is no less stunning than the conclusions themselves. His tools were not the hit-or-miss methods of Venetian seamen or Norse sailors but an adroit combination of carefully controlled observation, meticulously assembled quantitative data and rigorous logic. Only after a further half-millennium did anyone else apply such rigorous analysis to global exploration.

Having assembled all known knowledge of the subject, studying the wisdom of ancient Greeks and Indians as well as medieval Arabs and fellow Central Asians, Biruni devised completely new methods and technologies to generate his voluminous and precise data and processed it with the latest tools of mathematics, trigonometry and spherical geometry as well as the austere methods of Aristotelian logic. He was careful to present his conclusions in the form of hypotheses, on the understanding that other researchers would want to test and refine his findings. This did not happen for another five centuries. In the end European explorers confirmed his hypotheses and vindicated his bold proposals.

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