It is not true that fusion packs the highest punch of any known energy-generating process (“Ignition failed,” SN: 4/20/13, p. 26). Matter-antimatter annihilation far exceeds it (Star Trek had it right back in the 1960s). I believe that under certain conditions, matter falling into a black hole can also yield more energy than fusion.
Bobby Baum, Bethesda, Md.
The reader is right on both counts. But those approaches are impractical. Scientists have harnessed energy from fusion, even if it has not produced net energy. Energy has never been harnessed from matter-antimatter, and certainly never from a black hole. — Andrew Grant