A technology that can't be spoken of in the outside world... surely it must be one of Gensokyo's technologies, mustn't--Wait a minute.I don't have any idea what you're talking about, but...But in the outside world, "cold fusion"......is a prohibited topic, and to even speak of it is social suicide.Just as its name implies, it's nuclear fusion that occurs at low temperatures.It's a technology that would allow fusion without the high temperatures and pressures required by today's fusion technologies.Even now, the prominent physicists who worked on it remain consigned to dark obscurity.Even a winner of the Nobel Prize in Physics, Julian Schwinger, is said to have been shunned among the physics community just for expressing a genuine interest in such experiments.