large numbers of subatomic particles are popping into existence out of Nothingness, persisting for a tiny fraction of a second and then vanishing again, back into the Nothingness from whence they came. They are known as "virtual particles," and they normally pop into existence in pairs—a matter particle accompanied by an anti-matter particle. Every type of elementary particle that can possibly exist is a member of the set of virtual particles, popping/persisting/vanishing. This includes electrons, protons, neutrons, gluons, quarks, and of course pions, among many others. It happens that the pions that are involved in the strong force, holding nucleons together or causing nuclear fusion to occur, are always virtual pions. A peculiar fact about virtual particles is that no way exists to directly detect them during their moments-of-persistence. We can only detect side-effects of their having been there (such as the fact that lots of protons do stably exist together in the average complex atomic nucleus, or the observed energy that is released as a result of nuclear fusion). An even more peculiar fact is that, despite the inability (not-possible-even-in-theory) to directly detect virtual particles, while they exist, they are identical in every way to ordinary non-virtual particles. That is one of the keys to the hypothesis described in Part Eight of this document.
Another key is the fact that QM often describes a particle in an inexact or "uncertain" way. Statistics are a huge part of QM, and this most especially applies to the position or location of a particle. In general, the less mass/energy that a particle possesses, the less exactly its location can be specified. For a very light particle like the electron, the total amount of uncertainty in specifying its location gives us the impression it might be anywhere within a rather volumous region, rather like a cloud. Indeed, QM can give us the impression that sometimes the electron should be considered as existing simultaneously at every single point within that cloud.
3. Background: Deuterons and Nuclear Fusion
The "deuteron" is a particle that consists of just one proton and one neutron locked together by the strong nuclear force. It is typically found associated with an electron, and together they qualify as a member of the set of hydrogen atoms. On Earth about one hydrogen atom out of every 6500 is deuterium-hydrogen, with a deuteron as its nucleus. (Deuterium is sometimes called "heavy hydrogen," since a deuteron has twice the mass of the more-common hydrogen nucleus, and thus water made from pure deuterium is known as "heavy water.")
For it to be possible for two deuterons to fuse together, two things must have already happened to prepare the way. First, the electron normally associated with each deuteron must be stripped off. This is normal at extremely high temperatures, but that is not the only way it can happen, as described in Part Five. Second, the two deuterons must closely approach each other, despite the mutual repulsion they experience due to electromagnetic interactions. Extreme temperatures and/or pressures can make that happen, too, and thus do the stars shine as a result of many individual fusion reactions in their cores. It is obvious that if cold fusion can actually happen at ordinary temperatures and pressures, there must be another way to do this thing—and at least one such is known, as described in Part Four.
Before getting to that, though, it is necessary to describe something known as the "interaction cross-section." This is basically a measure of the volume of space surrounding a particle, in which it can significantly interact with a second particle. For the strong nuclear force, this range is pretty limited, but two deuterons must get within that range before they have any significant chance of fusing.
One way to describe the limits of the range of the interaction cross-section is to discuss virtual pions a bit more. It has already been mentioned that they can basically pop into temporary existence everywhere and all the time, but it needs to be said that while they exist, they can move a short distance before they vanish again. (This is normally highly related to the "cloudiness" of the particles. The less mass that virtual particles possess, the greater is the size of their cloud of possible locations, meaning the farther they can travel before they must vanish.) For the strong force, the distance that virtual pions can traverse (and pions are middling-weight particles) is closely linked to the range of the interaction cross-section. (For different nuclei there are other complicating factors that can affect the range, which don't concern us here.)
The simplest interaction between virtual pions and two adjacent deuterons goes something like this: In the space between the deuterons, a pair of pions pops into temporary existence. These are electrically charged (not all pions are neutral, and while every pion consists of one quark and one anti-quark, the charged pions do not contain mutually-annihilatable quarks). The negatively charged pion approaches the positively charged proton in one deuteron, while the positively charged pion approaches the neutron in the other deuteron. If the deuterons are close enough, the two pions will both be absorbed and vanish (ending their temporary existence) and the strong force (via plenty more virtual pions) will now be affecting the two deuterons, working to make them approach even more closely, against their mutual electrostatic repulsion, for final merging/fusing.
4. Background: Fusion by Muon Catalysis
This phenomenon was originally observed in liquid-hydrogen bubble-tanks at various particle-accelerator facilities in the 1950s. "Cold fusion" it most certainly is!
The muon was discovered by physicists while they were searching to find the predicted pion. It is almost identical to an electron, except that it is 206 times as massive as an electron and it has a natural lifespan of about 2 microseconds (while electrons seem able to persist forever). Neither electrons nor muons are able to "feel" the strong nuclear force; they mostly interact with other particles via electromagnetic effects.
During its short lifespan a muon is able to do quite a bit. For starters, it can replace the electron in orbit around a hydrogen nucleus, and because it has 206 times more mass than the electron, it orbits 206 times closer. A "muonic" hydrogen atom is quite a tiny thing, compared to a normal hydrogen atom. It also might be called "electrically dense." The electric charge of the muon is concentrated at the surface of the small volume of space which is a muonic hydrogen atom, while the charge of an electron in an ordinary atom is spread out over a much greater area. This fact allows the muonic atom to pass right through the electron shell of a neighboring hydrogen atom, simply because the electrostatic repulsion of that shell isn't concentrated/dense enough, to make the muonic atom bounce off (as it can easily do for other and ordinary atoms).
Next, inside the electron shell there is an electrostatic
