"We must remember that ET could be quite imaginative."
Am I the only one who finds this statement hillarious? Physicists today seem clueless about history. They thought they knew everything there is to know a hundred years ago and they still think so.
We may not recognize or even be capable of recognizing an alien signal.
That's one of my big gripes about the scientific community.What is unassailable now that schoolchildren will snicker at in another hundred years?
Listening for optical or radio signals may be as futile as watching for smoke-signals. Advanced alien races, and the probabilities of a large universe suggest they are out there, may use a form of communication which is even now blanketing the Earth. We just don't yet know how to receive it anymore than someone from the Middle Ages would know how to construct an AM radio receiver.