Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A great book, but much is written as theory.

I really enjoyed this book, Ann Moura has done a great deal of research throughout her life on this subject and has come up with a very believable theory backed up by a great many known historical events. Most of what she says is believable and based truly, but some parts, like the Dravidian culture's advancements aren't backed up by any evidence, she just claims that these people understood the atomic structure, light speed, and other things our culture has only "discovered" in the past 100 years. While it is possible that this happened... I would like some examples.