Informative conversation with K. David Harrison, assistant professor of linguistics at Swarthmore College near Philadelphia and the author of the new book "When Languages Die: The Extinction of the World's Languages and the Erosion of Human Knowledge". He is the Director of Research at the Living Tongues Institute and was recently featured in the documentary called "The Linguists" which followed hands-on linguistic field work in countries around the world. In this fascinating interview, Harrison discusses the critical importance of the world's many threatened languages and the vital knowledge that each language uniquely packages and holds for all of us. Harrison also discusses the need for more trained linguistic personnel to go out into some of the remotest parts of the world to document these nearly extinct languages before they are lost to humanity forever.