If you are interested in hearing more expert commentary, NPR Science Friday did a piece on this in July:<p><a href="http:&#x2F;&#x2F;www.sciencefriday.com&#x2F;segment&#x2F;07&#x2F;17&#x2F;2015&#x2F;redefining-the-kilogram.html" rel="nofollow">http:&#x2F;&#x2F;www.sciencefriday.com&#x2F;segment&#x2F;07&#x2F;17&#x2F;2015&#x2F;redefining-t...</a>