User blog comment:Elseweyr/Mass Effect bubble soon punctured?/@comment-8419211-20130725213545/@comment-9753034-20130730153348

No problem, I did struggle to see the connection there... But yeah, dark energy (and matter, though it's not clear whether these are different concepts and if so, to which extent) is just a term for that missing chunk of the universe we can't detect. So far we've had no luck in determining exactly what it is or what it does. (Or why, but let's not go there.)