There is a long Thread on this subject.
The advocates remind me of the Creationists who introduced Intelligent Design to disguise themselves & push their views from another direction.
What is now called LENR (Low Energy Nuclear Reactions) used to be called
Cold Fusion.
For those with little knowledge of the pertinent physics
:
Electromagnetic forces are circa 10[sup]37[/sup] greater than gravitational forces. For those who do not grok 10[sup]37[/sup], note that a small magnet can cause a steel pin to jump off the surface of the earth.
The repulsive force between positive nuclei is so strong that it is hard to visualize.
Nuclear fusion occurs in stellar cores where there are extreme temperatures & pressures.
Note that temperature is a measure of average particle speed. In stellar cores atoms & nuclei have very high speeds. The extreme pressure makes the core dense, increasing the probability of collisions.
The environment in a stellar core is required for nuclear fusion. It is not possible in other envorments. For decades there have been attempts to cause fusion by laser implosion. There has been little success, although recently the experiments have come close to breaking even (energy input close to energy output). I do not think the process is close to being commercially viable.
The notion of Cold Fusion is considered nonsense by anyone with a knowledge of nuclear physics. Advocates of it have a belief based on faith, but do not have much knowledge of nuclear physics.
Before somebody else mentions it
: There is the possibility of quantum tunneling which might result in one fusion event per century in a one kilogram mass. This is a SWAG (Sophisticated Wild Ass Guess), which is a lot better than a WAG. It is suggestive of the real frequency.