 Welcome to the Endnotes, where I put all the fun facts I can't fit into the main videos. Today, some extra bits of information for my video about nation. And if you haven't seen that yet, click on the card. In that video, I briefly mentioned some of the linguistic arguments against an out-of-India origin for the Proto-Indo-European language and language family. Here's a little more detail on how the vowels found in Sanskrit and other Indo-European languages indicate that Sanskrit must have come from a common source with the other Indo-European languages and is not itself the source of the language family. Sanskrit has the primary vowels a, e, and u. These were originally assumed to be the original vowels in the Proto-language, and e and u in Sanskrit correspond to those same vowels consistently in the cognate words in other languages. But a in Sanskrit corresponds seemingly randomly with a, a, and o in the cognates, and coming up with a regular sound change to explain this has proved difficult. However, if we instead assume that the Proto-language had the original vowels a, a, and o, which were preserved as distinct in some of the Indo-European subbranches, but changed as they developed into the Indic branch, that would solve the problem. With the comparative reconstruction of pi, philologists further noticed evidence for a sound change of a sometimes becoming a or o. To explain this, it was proposed that there must have been laryngeal sounds, that is something like a h present in proximity to those vowels, which came in three types. h1, which was neutral and didn't change the a, h2, which was a-coloring and changed the a to a, and h3, which was o-coloring and changed the a to o. But in all cases, these laryngeals had disappeared before any Indo-European language then known was recorded, including Sanskrit, meaning that Sanskrit couldn't be the original language. The real strength of the laryngeal theory is that when the Hittite language was later deciphered and shown to be an Indo-European language, it was discovered to have preserved some of these laryngeal sounds, thus demonstrating that it must have branched off very early, preserving some of these and other archaisms. This clearly makes it relatively older than Sanskrit and the whole Indic branch of Indo-European. As always, you can hear even more etymology and history, as well as interviews with a wide range of fascinating people on the Endless Knot podcast, available on all the major podcast platforms, as well as our other YouTube channel. Thanks for watching!