How do I make this RDF validate?

I'm trying to switch to RDF for metadata, and it seems that I must be missing a declaration somewhere? Can someone point me in the right direction? Or is this a problem with the validator?

Page:

http://www.pushback.com/Wattenburg/TechnicalArticles.html

Validator output:

a.. Line 25, column 19: 
  <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
                     ^
Error: there is no attribute "xmlns



RDF code:

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:dc="http://purl.org/dc/elements/1.1/">
  <rdf:Description rdf:about="http://doc"
      dc:identifier="http://www.pushback.com/"
      dc:title="[PushBack] Dr. Bill Wattenburg&#8217;s Scientific and Technical Articles"
      dc:subject="Dr. Bill, Will Harvey, Wattenburg"
      dc:description.abstract="Scientific papers and other technical articles written by Dr. Bill Wattenburg."
      dc:date="2001-10-10"
      dc:creator="Peter K. Sheerin"
      dc:contributor=""
      dc:publisher="PushBack.com"
      dc:rights="Copyright 2001 Peter K. Sheerin--All rights reserved."
      dc:language="en-us"
      dc:format="text/html"
      dc:type="article"
      />
</rdf:RDF>