“However given the laws of physics its a virtual certainty that no biological alien has ever visited the earth ...” Well that answers my immediate question regarding how idiotic a statement ... and the poster doesn’t even comprehend how stupid the assertion is that we know ALL the laws of Physics. In fact, we are discovering that we poorly comporehend the laws we’ve discovered! Even Maxwell’s equations ahd solutions which call into question the Einstein theory of general relativity being the end all of Physics laws!
It’s settled science. They have consensus. See? simple! /s