Null Set Blogging

By Matthew Yglesias
Nullset.png Sure, Mitt Romney is crazy wrong about Iraq, but that's normal for a Republican. I'm more interested in his weird use of the term "null set." While researching that topic, I learned something interesting. It turns out that the thing I was taught to call either "null set" or "empty set" is now supposed to be the empty set exclusively. The purpose of this is to avoid confusion with a different concept, also called that comes to us from measure theory:
In measure theory, a null set is a set that is negligible for the purposes of the measure in question. Which sets are null will depend on the measure considered. Thus one may speak of "m-null sets" for a given measure m.
In neither sense, however, does what Mitt Romney said make sense.

This article available online at:

http://www.theatlantic.com/politics/archive/2007/06/null-set-blogging/42327/