[quote]When activated, the Halo rings would wipe out all sentient life within three radii of the Milky Way's Galactic center, by sending out radiation, targeting certain cells in the nervous system, which includes, but is not limited to, neurons, by harmonizing all neurological frequencies. [/quote] they have a much better radius then 1 millimeter. Now that I read this, the Halo rings don't destroy planets, they destroy life. Which is much better for colonization and warfare purposes.