Lets use http://en.wikipedia.org/wiki/SI SI units, shall we? 40 Gigagrams of uranium.

PS: I couldn’t figure out how to create proper links, and I am too tired to keep on looking...

I have tried using the Britannica site a few times in the past, and I just tried again now. It isn't very good, is it? I mean sure maybe it's all accurate, but on Wikipedia I find what I am looking for within a few minutes, mostly within seconds. Once you get there, the pages are relatively easy to read.

Go on, have a look at Britannica.com... Tell me what you think... What do you think most non-geeks will go back to, Wikipedia or Britannica?