The four ages of sand January 10, 2013 General http://www.douglasadams.se/stuff/sand.html Ed Dowding Founder, strategist, writer, gadfly, TED talker, world-record holder, and (foolishly) reality-TV farmer. DOES: Innovation, Product, Advocacy THINKS: Regenerative Systems, Institution design, 300 year horizons Post navigation PreviousPrevious post:The Generals by Shel SilversteinNext Next post:The world is on track for disaster. Who wants to buy a farm? Leave a Reply Cancel replyYou must be logged in to post a comment. This site uses Akismet to reduce spam. Learn how your comment data is processed.