This is not a joke, it's an excellent article by Michio Kaku. Appropriately, Jay Manifold of A Voyage to Arcturus has the link, and some thoughts of his own as well. As Michio's article notes:

"Although any conjecture about such advanced civilizations is a matter of sheer speculation, one can still use the laws of physics to place upper and lower limits on these civilizations. In particular, now that the laws of quantum field theory, general relativity, thermodynamics, etc. are fairly well-established, physics can impose broad physical bounds which constrain the parameters of these civilizations. This question is no longer a matter of idle speculation...."

Especially when new telescopes may be able to start finding other solar systems that could theoretically support life. Michio talks about different levels of advanced civilization (it's a function of their energy usage level), why SETI may not find any messages even if they're out there, how a really advanced civilization would explore the galaxy, and more. Fascinating read.