Chapter 10 introduces us to Phillip Morrison the professor at Cornell University who thought of using radio waves to search for Extra-terrestrial life. He was listeningto Bach music at a concert there when a number or events congealed in his mind to come up with using radio waves instead of gamma waves as a signal to other universes.
They then discuss some of the other ideas people had to contact other "people"- planting trees in right triangles, flaming ditches, etc.
One of these people was Precival Lowell who built the Lowell Observatory in Arizona . Pretty cool huh?