Part 2/9:
At its core, nuclear fusion occurs when two small atomic nuclei combine to form a larger one, releasing vast amounts of energy in the process. This reaction is the same one that powers the sun, and it typically requires extreme heat and pressure to overcome the strong electrostatic repulsion between positively charged nuclei, known as the Coulomb barrier.
In the realm of cold fusion, the premise is that it might be possible to facilitate this process at significantly lower temperatures and pressures by using solid-state materials. In this approach, isotopes of hydrogen, such as deuterium, are placed within a solid metal matrix—often palladium—with the hope that these conditions could lower the electrostatic repulsion enough to allow for fusion to occur.