In 1066, William the Conqueror invaded Britain and brought with him fancy French words to add to the English language.

Over the course of human history, thousands of languages have developed from what was once a much smaller number. How did we end up with so many? And how do we keep track of them all? Alex Gendler explains how linguists group languages into language families, demonstrating how these linguistic trees give us crucial insights into the past.

What does the Holocaust have to do with us, anyway? In part four, Roderick Miller, the chair of the nonprofit organization Tracing the Past, gives a talk at TEDxVienna about the Holocaust and contemporary Europeans' perception of the space they live in.

What does the Holocaust have to do with us, anyway? In part three, Roderick Miller, the chair of the nonprofit organization Tracing the Past, gives a talk at TEDxVienna about the Holocaust and contemporary Europeans' perception of the space they live in.

What does the Holocaust have to do with us, anyway? In part two, Roderick Miller, the chair of the nonprofit organization Tracing the Past, gives a talk at TEDxVienna about the Holocaust and contemporary Europeans' perception of the space they live in.

What does the Holocaust have to do with us, anyway? In part one, Roderick Miller, the chair of the nonprofit organization Tracing the Past, gives a talk at TEDxVienna about the Holocaust and contemporary Europeans' perception of the space they live in.

In this historical speech, Barack Obama speaks of the greatness of the multiculturalism of the United States of America, and how it is a tool that will help us overcome all difficulties.

We take you to the front row of this historical speech. Let’s listen to Barack Obama’s words of wisdom as he becomes the 44th President of the United States of America.

January 20th of 2009 was an important day in American history. The words “change” and “hope” were heard that afternoon in Washington, D.C., as Barack Obama became the 44th President of the United States. Don’t miss a word of his speech!