The story ‘Macroscope’ by Piers Anthony is not science fiction, except that it models the situation as technological. The -actual- situation requires ZERO technology. The ‘signal’ is in your cells. It is the ‘lock on the Tree of Life’ in Eden, and if you unlock it — the signal BLAZES FORTH INTO YOU. ONLY children shall pass, and the adults shall be annihilated. No adult shall pass that gateless gate!