If you are interested in hearing more expert commentary, NPR Science Friday did a piece on this in July: http://www.sciencefriday.com/segment/07/17/2015/redefi

If you are interested in hearing more expert commentary, NPR Science Friday did a piece on this in July: http://www.sciencefriday.com/segment/07/17/2015/redefining-the-kilogram.html http://www.sciencefriday.com/segment/07/17/2015/redefining-t...