What is the total population in India?

Comparing India and China, why are there so many more languages spoken in India compared to China, and what explains the mass adoption of a single language (Mandarin) in China among a population as large in size as India and spread over a large land mass?

• It seems like India evolved many many languages that are considered truly independent and mutually incomprehensible (not considering dialects as separate languages), but the same did not happen in China at the scale that it happened in India, although the countries are somewhat similar in size and population. Going by memory, 80% of Chinese speak Mandarin (or its dialects) as a first language, while only 40% of Indians speak Hindi (or its dialects) as a first language.

• Answer:

  I don't know if this is a proper reason, but the concept of India is relatively new. The Indian subcontinent has been ruled by several kings, but only the British rule covered India as well as the current territorial boundaries of India. There might have been bigger kingdoms, like Chola or Maurya, etc, but they never lasted long enough or were wide spread over different nations. So India was never a monolithic culture. Before the British, it was the Marathas who almost got hold of the entire country but they too didn't last long. Mughals controlled the north for an extended period of time, so that region is somewhat homogenized. They only made inroads to the south during Aurangzeb's reign and quickly collapsed after his death. In contrast, China (at least the eastern part) has been completely under control of a single dynasty for most part of the history, since the Han Dynasty. The ruling dynasty changed, but the region controlled remained the same. This was interrupted by the http://en.wikipedia.org/wiki/Three_Kingdoms period (60 years), the http://en.wikipedia.org/wiki/Southern_and_Northern_Dynasties period (~170 years) and http://en.wikipedia.org/wiki/Five_Dynasties_and_Ten_Kingdoms_period (~70 years). So a total of 300 years of different rulers out of a 2200 year old Chinese history since the Han dynasty. That sort of a thing is rare indeed. It allows homogenization of language and people. Even then, we have multiple languages spoken there. The Tibetan region speaks a different language since it was a independent kingdom for a significant amount of time. The western parts of China also speak a different language. Also most Chinese people you would meet are ethnic Han so they would be either speaking Mandarin or Cantonese. You rarely interact with Tibetan Chinese (maybe more in India) or Xinjiang Uyghur who are ethnically different from Han Chinese. So, a combination of homogenization and confirmation bias, is the answer to this question.