: : How can gravity waves exist if gravity requires some body of mass??

: They don't require mass as a medium of propagation.

: :Any good articles out there on the web? Look for "gravitational waves" with your search engine. I found these.

http://www.letsfindout.com/subjects/space/ligoin.html

http://www.ligo.caltech.edu

You also might read a book "Black Holes and Time Warps" by Kip Thorne, et al. It is a great non-technical (little math) discussion of General Relativity and all its ramifications, including gravity waves.