This may seem like a departure, but bear with me. This will be explained in a later posting. In the search for extraterrestrial intelligence (commonly known by its acronym SETI), the several programs around the world, including at U.S. National Aeronautic and Space Agency (NASA), must have criteria for declaring the discovery of ETI. Our One Signal In 1977, a radio telescope at Ohio State University received a very strong radio signal. Astronomer Jerry R. Ehman, reviewing the