A researcher in Genetics, from Harvard University, asked
If the texts are the same, and the movement of the planets deterministic, why are there widely varying ranges for the astrological dates for the Rig Veda?
This is indeed a pertinent question and a frequently asked question (FAQ). Of course, the issue is not limited to the text of Rigveda.
First, let’s clarify – there is no decisive astronomy evidence within Rigveda, that by itself allows dating of Rigveda.
We are talking about ‘astronomy’ and NOT ‘astrology’.
Like any other field of research, ‘chronology research based on astronomy’ has its own charlatans. Of course, at times, these are genuine errors and not intentional frauds (we all are prone to err).
Interpretations of evidence
Anyone working in genetics & statistics would know why the same set of data can lead to different interpretations, inferences, conclusions. There is indeed an element of this in determining the chronology of Mahabharata, Ramayana, Rigveda and such.
Thought experiments, technology & objective testing
The multiple theories/claims proposed can also be due to the complexity of the problem and inability of technology to not keep up with what scientists want to test (theories, conjectures, thought experiments, etc.)
Quantum mechanics results and our technological ability to test multiple theories in QM is a good illustration.
The reason for widely varying ranges for chronology (e.g. Mahabharata – 7300 BCE through 500 BCE) based on the same texts is due to mix of right and wrong approaches to doing research.
Multiple methods employed by over 130+ researchers can be classified – scientific, non-scientific, dogma, cognitive dissonance, ignorance of modus tollens vs modus ponens, inductive vs deductive reasoning, use of selective vs. all evidence, inference based on evidence vs. inferences that override evidence, etc.