Mention ‘fusion’ and most people will first think you are talking about a new restaurant. Only a few techy types who read scientific journals will pick up on a cutting-edge technology for power generation. Fusion is a type of nuclear reaction, but unlike the nuclear power already in use wherein atoms are broken apart, through fusion reaction energy is created by smashing together two atoms at high speed. Triggering such atom collisions requires tremendous heat. Thus far, scientists have had difficulty finding a heat process that generates more energy from the fusion reaction than it takes to spark it. The challenge is called ‘energy gain.’
It is not like mankind does not already have a perfect fusion example to use as a model. Fusion reactions can be found naturally in the core of stars. Indeed, at the core of our own Sun hydrogen atoms combine to make heavier elements like helium with the resulting power bathes Earth and its neighboring planets in light and heat. Duplicating that in a controlled process is proving a tough nut to crack.