Going Public with a Theory: What is Libel?

I'd like to ask a question of anyone reading this who possesses any
legal knowledge. I have a theory concerning a current event, and I'm
thinking I might as well go public with that theory. I have no proof for
the theory, nor do I wish to pretend to have any of that proof, but to
me it does fit the facts as I understand them. While I'd like to go
public with this theory, I don'g want to be guilty of libel, slander,
defamation, or anything else like that. I would like to know what, in
general terms, would constitute libel and where the line is drawn
between libel and opinion/conjecture. Anyone want to take this question?

Bleh

Well I just saw the computer from Tiger Direct that I should've gotten
instead of that Dell desktop that I chose. Only five hundred bucks, too,
as opposed to what I paid. But I was looking for the fastest processor I
could find, and I take full responsibility for my mistake. Too late now.