I found it in Crash Course World History. It is at around 1minute and 44 second. Here is the context:
Another change in psychology: many historians of the now note that globalization has also led to a celebration of individualism.
I have checked a few dictionaries, and I could not find any example where the noun now was used with the definite article. Could you pleasd tell me why the host used it. Does the bear any additional meaning in the sentence?