Definition— The Great Divergence or European miracle is the socioeconomic shift in which the Western world (i.e. Western Europe and the parts of the New World where its people became the dominant populations) overcame pre-modern growth constraints and emerged during the 19th century as the most powerful and wealthy world civilization, eclipsing Mughal India, Qing China, the Islamic World, and Tokugawa Japan.
According to Wikipedia there seems to be two conflicting viewpoints on this subject.
The traditional school of thought believes that Europe diverged from the rest of the world by the 15th or 16th century due to the commercial and scientific revolutions, mercantilism, colonialism, etc.
While the “California school” considers the Industrial Revolution in the 18th and 19th centuries to be the only “great” diverging point between Europe and Asia.
A secondary question; As subjective as academic answers to broad and complex questions like these will be, what is the “right” — to speak in extremely oversimplified terms— perspective on the Great Divergence in your own opinion?
This is one of those questions where I hate to do this, but the simple answer is to read Ken Pomeranz' The Great Divergence, which gave a name to this range of historiographical debates. It's a somewhat challenging read because Pomeranz insists that the answer lies in very fine-grained details. E.g., if you want a single simple explanation ("it's the concept of secularism in Western Europe! It's the loss of value of silver as a global currency after 1500 due to Potosi! It's the way scientific inquiry was valued after the Renaissance!" and so on) you will not find it in Pomeranz' exacting review of all the major differences between the political economies of East Asian societies and those of Western Europe between 1350 and 1900. What you will find is a complex model that takes into account information like the relative depth and ease of extraction of coal deposits, particular details of systems of taxation and administrative control, and so on.
I mention the point about coal in particular because Pomeranz thinks that's an especially important detail and one that only comes into play in the 19th Century. Ultimately Pomeranz comes down on team "it's mostly the 19th Century where the divergence happens, and it's not just a question of the existing differences between the two regions at the time but also of the specifics of the relations between them in the world economy of the time (e.g., the divergence is at least partially a consequence of relational actions)."
My own specialized knowledge leaves me unable to do anything with Pomeranz' analysis of East Asian political economy--I can only say that he sounds convincing. On the Western side, I think maybe he underrates some of the complicated prior impact of the Atlantic system on Western Europe--a topic that's also under renewed historiographical scrutiny lately. That is a kind of "well, both" answer--e.g., it makes 1700-1750 a key inflection point for divergence between these two core regions in terms of movement towards industrialization.
There's also a complicated whiff of modernization theory and its teleological assumptions hanging around the entire discussion, as if industrialization was a natural outcome towards which any wealthy or powerful society in 1750 ought to have been trending, as if history is a race towards a predetermined end, and that too takes some rethinking at this point. But that's a huge can of worms to open up that goes well beyond arbitrating the specific debate about the "great divergence".