I have been interested in the story of halo lately. I have trying to come up with a way to theoretically create a mechanism that kills all life via radiation in a 25,000 ly radius. (The function of a halo ring). This is what I have so far, using millions of lasers focusing on one point. Using stefans law, all the lasers fire at this perfect black body with all length dimensions of one and raises its temperature up to the planck temperature (highest possible temp ~10^32) P = (10^-8)(10^32)^4 = 10^120 J/S Since, I am a beginner at physics I don't know where to go from here. I need it to be enough energy to kill all life within a radius of 25,000 ly.