In the 21st century historians have increasingly portrayed the decade as a "pivot of change" in world history focusing especially on the political and economic upheavals. Check your 70s knowledge.
If you want to put your video files online using HTML5 then it's recommended to have three different formats for a full browser support. Those formats are mp4, ogv and webm.
Truly amazing work by the NYC Grid guys creating images composed of two images at the exactly same location only decades or sometimes even century apart.
