Is there a fundamental flaw in why we have not received a signal from an advanced alien civilization? How do we decode an alien message –alien is alien so it might be impossible. What if they communicate chemically? Will they use the language of math and science signaling at 1420 megahertz? What if we are too primitive to comprehend a message or the technology of its signal that may exist in a form beyond matter? What if it’s a message from an extinct civilization astrophysicist such as Harvard’s Avi Loeb believes exist in our galaxy? Or, as John Gertz suggests for Scientific American, maybe the aliens are already in our solar system, probably in the form of robotic probes.