VCAA2: The Main Argument for Pingree's Theory

Now, how does Pingree know that this is what Aryabhata did some 1,400 years ago? His key argument is that if we use Ptolemaic calculations to reproduce Aryabhata's supposed steps, then we obtain Aryabhata's parameters for mean planetary motion almost exactly. Aryabhata's parameters, listed under R in Table A2.1, are in the hundreds of thousands and millions. Column (1) of this table lists the differences between Aryabhata's parameters and these parameters as reconstructed by Pingree. For example, for Jupiter, Aryabhata's rate is 364,224 revolutions per yuga cycle, and Pingree's reconstruction is larger than this by 4. Since these differences are very small, it is hard to imagine how Aryabhata could have arrived at his parameters without following the scenario that Pingree proposes. This makes it seem that Pingree's conclusion concerning Aryabhata is indisputable, and equally so his contention that nearly every aspect of Indian astronomy was imported from Greek sources without acknowledgement (PG, pp. 114-15).

An argument such as Pingree's has a great impact on the academic world. It tends to be immediately convincing to scholars, and it becomes established as a foundation stone in an imposing school of thought that cannot be easily challenged by nonprofessionals. As a result, scholars in other fields (such as comparative religion and history) accept the conclusions of such a school as a matter of course, and modify their own views in accordance with it.