I've primarily studied physics of the 19th-21st century, so I can't provide a detailed accounting of the history of this subject for the period before. The records before circa 1800 are less complete, less common, and more difficult to decipher due to the unique terminology employed by every single discoverer of this physical phenomena. Suffice it to say that this phenomena has been harnessed for a long time and observed for a very long time. Any time you see ball lightning in ancient artwork: you are seeing the record of an observation of a huge macroscopic plasmoid/exotic vacuum object/etc (hereafter referred to mostly as plasmoids for simplicity). Plasmoids are as natural as sunshine and lightning. They mostly exist at the microscopic scale beyond our ability to directly perceive. Occasionally the environment is ripe for mother nature to generate ball lightning as in the Hessdalen lights of Norway. In extreme situations ball lightning can be a yard/meter in diameter. During earthquakes and volcanic eruptions in particular, the forces at play are so intense as to be difficult to comprehend. When the right elements are moving relative to one another with the right dynamics, you get ball lightning. Unfortunately ball lightning isn't so common as to be readily studied in nature. Until recent decades it was often considered an urban legend or myth. Thankfully the advancement of mobile camera technology has dramatically increased the documentation of natural ball lightning. Once you accept that nature produces such a phenomenon rarely it's only a small step from there to accept that it's possible for humans to engineer the conditions that produces such a phenomenon on command. Just as we see nature produces light and lightning and we humans also make our own (smaller!) light and lightning. Ball lightning is what plasmoids are called when you find them in nature. Plasmoids are what you call ball lightning that's made in a lab.
Let's start with John Ernst Worrell Keely. By today's standards he's regarded as a quack inventor at best and a fraudster at worst. By 1872 he had created a sort of steam engine that you need only crank to start, then it would be self-powered by water. Modern debunkers assert he secretly employed air compressors to drive the apparatus and thus was a complete fraud. Though a closer look at what he built reveals that he created engines which generated a lot of water cavitation using multiple methods (clever geometry, resonant effects, etc), which means he was definitely making plasmoids.
Any time you're generating a large quantity of water cavitation some fraction of those cavitation bubbles will collapse forming Rayleigh jets with a very fine tip which experiences immense pressures and temperatures and voltage over a infinitesimal area. Any type of hard sharp punch (including a powerful laser pulse) will produce in electromagnetism what is called a toroidal moment where the electric and magnetic fields bend back into each other, forming a closed tube shape that connects to itself: a hollow doughnut. This is a semi-stable field configuration that can last from mere moments to at least months depending on the environment. Macroscopic plasmoids intentionally created in a lab typically last on the order the 2 seconds to 2 minutes. Plasmoids are readily trapped and kept stable at lower powers in metal lattices for long periods, at least months.
John Keely used a steam engine type design to drive pistons to do work. In recent years there have been numerous much simpler systems working on the same principle. Some call them "nuclear siphons" because the cavitation is driving a tiny nuclear reaction by the use of short-lived plasmoids. This nuclear reaction manifests as anomalous pressure and temperature at the site of the water cavitation. Using clever geometry it's possible to connect together some mundane PVC water pipes together such that they'll cavitate in a way that pushes water uphill. Water cavitation is perhaps the simplest low-tech way of generating (tiny) plasmoids and its effects have probably been rediscovered many times by many people.
Nikola Tesla independently discovered plasmoids by circa 1890 when experimenting with high power disruptive electric discharges (not resonating, not oscillating, but just unidirectional periodic sharp pulses of high voltage). When he placed a single-turn copper helix by the spark gap that coil “[…] become ensheathed in an envelope of white sparks. Undulating from the crown of this coil were very long fluidic silvery white streamers, soft discharges which appeared to have been considerably raised in voltage.”
The sparks surrounding the coil (and the plasma streamers) is a very strong sign that in that configuration he was making plasmoids. This same effect is documented by Takaaki Matsumoto and Ken Shoulders. Some describe the sparks as forming a kind of Pearl necklace, beads on a string, etc. Closer examination of these “sparks” shows they’re super-tightly-wound plasma structures in the fractal toroidal shape. It was precisely this "Tesla Impulse" technology that he was designing as the enabling basis for his "Radiant Energy" that he wished to broadcast to all homes without wires. Pulsed Tesla Impulses are capable of generating very high power radio waves, orders of magnitude stronger than any similarly-powered radio transmitter.
In the 1940s the German's were experimenting with various high-power radar technology (high power continuous radio waves). There are reports that crossing of two such radar beams (such as when two radar stations track the same enemy plane) would occasionally create macroscopic ball lightning that the allied pilots called "foo fighters."
In the 1950s the US federal government was spending many billions of dollars on nuclear weapons technology and nuclear technology more generally. They had achieved nuclear fission. They had also achieved limited nuclear fusion in the form of hydrogen bombs. There was considerable effort advanced by Truman in 1953 to use "atoms for peace." This meant in part that money previously spent exclusively on nuclear bombs and their enabling technology would be expanded to include energy-generation technology of both the fission and fusion types. At the early part of the atomic age many scientists were optimistic they would quickly find a way to do controlled fusion which can provide unlimited clean energy almost for free.
One scientist working on "atoms for peace" projects was Winston Bostick. Among other things by 1956 Bostick had created a z-pinch plasma gun that would produce plasmoids on command. More than any other scientists mentioned in this list, Bostick was an insider to the US nuclear regime. He was an Chicago-trained nuclear physicist that worked at MIT, Los Alamos, Lawrence Livermore, etc.
Bostick published several papers and some of his work was discussed in mainstream press. His line of research into fusion via plasma confinement then goes dark. It appears likely that his fundamental research successfully led to nuclear energy and nuclear bomb applications. All knowledge related to high-end weapons and energy systems are tightly controlled by the US federal government. Remember that scientists made nuclear bombs with pencils and slide rules in the 1940s, so clearly it has to be the case that the key relevant engineering dynamics aren't that complex. This is why you can't let the information be shared too broadly: you want to maintain a monopoly on advanced weapons and energy technology that gives you an edge over rival nations. The most advanced technology will be held back as secret for as long as possible, only shown publicly and admitted when forced by events.
In the 1960s engineer inventor Josef Papp created his "Noble Gas Engine." Papp did not disclose theories for it's mechanism of action and kept key aspects of his design secret. He was an engineer, not physicist. The main technical mechanism was a powerful sharp electric arc discharge into a rarified ionized noble gas. These are the exact conditions that create plasmoids reliably. Papp had created an engine using thorium sand and noble gases to drive pistons via the force of a coulombic explosion resulting from the quick destruction of a plasmoid created moments earlier. His engine produced hundreds of horsepower. John Keely had a century earlier invented essentially a steampunk version of the Papp engine: both derive their motive force from exploding plasmoids.
In the 1970's hobby electronics enthusiast John Hutchison undertook efforts to reproduce Tesla's Impulse experiments. John had created his own Tesla disruptive discharge devices and had acquired numerous pieces of surplus military radio equipment. Using a combination of the two John could rarely (at most once after a full day of trying) produce what he called the "Hutchison Effect". This effect was able to make aluminum glow and bend like putty without being hot. This effect allowed dissimilar materials to be welded together. This Hutchinson Effect is one manifestation of the creation of plasmoids inside metals.
Kenneth R. Shoulders was an experimental physicist who worked at MIT, Stanford, and the CIA. He was an early pioneer of electron beam lithography and inventor of numerous patents. He's widely recognized as a founder of microelectronic field emission devices. In the 1980's he committed himself to the study of the "Hutchinson Effect" after urging by Hal Putoff of SRI. He initially called the phenomena "Electrum Validum" (EV) and later "Exotic Vacuum Objects" (EVOs) when he realized the underlying electromagnetic toroidal moment driving the key aspects of the unusual properties and effects. He was an excellent experimentalist and successfully designed an apparatus to generate plasmoids on command and vary their intensity. He wished to disclosed what he learned though was under CIA contract at the time and knew his research would be suppressed if he brought it to them. To side-step this problem he wrote a book called "EV: A Tale of Discovery" and distributed copies to numerous people. Since "the cat was out of the bag" it was not possible for his findings to be completely suppressed. This enabled Ken to file several patents describing apparatus for creating plasmoids. Even so, Ken's plasmoids remained just as undiscussed outside of fringe circles as Hutchinson, Papp, Bostick, Tesla, and Keely before him.
In 1989 Martin Fleischmann and Stanley Pons reported detecting excess heat during electrolysis experiments using deuterium-droped palladium electrodes. This was then reported was "cold fusion". Their apparatus only produced this effect infrequently. The specific microstructure of the palladium mattered. Although unreliable, this method occasionally produced plasmoids though they didn't know it.
In the 1990s Stanley Meyer invented a "water fuel cell" (WFC) that generated HHO gas by using high-voltage low-current pulsed disruptive electric discharges through pure water contained in a space between two steel plates. The rate of the electric pulses varies the HHO production rate. While Tesla used relatively much larger and more powerful mechanisms, Meyer used the smallest weakest mechanism that could get the job done. Meyer's mechanism makes lots of microscopic plasmoids which quickly explode, splitting water as a side effect.
Also in the 1990's Japanese nuclear physicist Takaaki Matusmoto undertook to study the work of Pons and Fleischmann, trying to reproduce and make reliable their discovery. Takaaki eventually succeeded at producing plasmoids reliably, which he at first called "itonic clusters" and later accepted was the same thing as "ball lightning." Takaaki's efforts are well-documented in published scientific papers which are reprinted in a book titled "Steps to the Discovery of Electro-Nuclear Collapse: Collected Papers (1989-1999)."
Since circa 2012 Bob Greenyer has been studying Low-Energy Nuclear Reactions (LENR) as a researcher at the non-profit Martin Fleischmann Memorial Project (MFMP) he formed. He has a degree in engineering and is a serial entrepreneur with high intuitive genius and vision. Bob Greenyer undertook empirical studies of artifacts produced in the material directly involved in "over unity" LENR devices and discovered regular shapes and kinetics that led him to intuit the shape and dynamics of the entity producing the marks. Bob subsequently learned that these shapes and these effects had been produced by many people in many ways. Bob Greenyer is arguably the most knowledgeable non-experimentalist with respect to plasmoids in the entire world. If you want to learn about plasmoids you must subscribe to his work.
Plasmoids can be used as batteries/capacitors storing more charge per unit volume than any other known method. Plasmoids charged with enough amps can be used as super compact coulomb bombs capable of producing nuclear-level explosions without requiring nuclear materials. Plasmoids can split water. Plasmoids can do fusion and fission. Plasmoids sound like magic, hence why they get associated with "over unity" device claims. Are plasmoid-driven devices "over unity" type "free energy" devices? Sort of yes, mostly no. If you only look at the input electricity vs. the output power, then yes they're very much over-unity. Though in reality plasmoids perform nuclear chemistry and are powered by this. Plasmoids are tiny little nuclear reactors with the best radiation shield ever devised surrounding them: closed-loop plasma. Plasmoids consume whatever atoms are nearby (and relic nutrinos), fissioning and fusing them into new atoms. Depending on the atoms getting fused these reactions can generate more or less energy, as in conventional fusion.
Almost all mainstream scientists accept the model of stars as being powered by fusion that was initiated by the effect of gravity on a large cloud of hydrogen. Gravity is a very weak force. If gravity can produce fusion why not the electromagnetic force that is about 40 orders stronger than gravity? This is what plasmoids do: they harness the electromagetic force to do nuclear chemistry.
Context:
http://www.rexresearch.com/evgray/1gray.htm
https://epistemology.locals.com/post/6015937/physics-book-keely-and-his-discoveries
https://epistemology.locals.com/post/6011226/physics-vladimir-pavlovoch-torchigin-nuclear-siphon
https://epistemology.locals.com/upost/5846404/physics-adrian-marsh-tesla-s-radiant-energy-and-matter
https://epistemology.locals.com/post/5273391/physics-kladov-cavitation-destruction-of-matter-lenr
https://epistemology.locals.com/upost/4926740/book-dr-john-desalvo-the-complete-pyramid-sourcebook
http://www.rexresearch.com/roschin/roschin.htm
https://epistemology.locals.com/post/5050854/physics-study-g-c-dijkhuis-a-model-for-ball-lightning
https://epistemology.locals.com/post/4950157/physics-david-fryberger-a-model-for-ball-lightning
https://epistemology.locals.com/post/4950183/physics-book-oliver-heaviside-electromagnetic-theory
https://epistemology.locals.com/post/4942359/physics-george-egely-faces-of-lenr
https://epistemology.localcom/post/4942921/physics-registration-of-high-energy-radiation-from-magnetised-water-exposed-to-scattered-sunli
https://epistemology.locals.com/post/4942990/physics-bob-greenyer-what-really-is-new-fire-fuel
https://www.nanosoft.co.nz/Fusion.php
https://epistemology.locals.com/post/4926506/physics-toroidal-models-of-electron-and-proton
Quest for zero point energy book moray b king:
https://epistemology.locals.com/post/4927907/title
https://epistemology.locals.com/post/4925433/physics-vortex-lattices
https://epistemology.locals.com/post/4926069/boyd-bushman-of-lockeed-martin-on-antigravity
https://epistemology.locals.com/post/4920922/physics-needing-more-study4
https://epistemology.locals.com/upost/4917234/physics-book-the-hutchinson-file
https://epistemology.locals.com/upost/4917242/physics-cavitational-destruction-of-matter-by-a-kladov
https://epistemology.locals.com/post/4917423/physics-v-e-zhvirblis-the-bagel-game
https://epistemology.locals.com/post/4878522/physics-needing-more-study3
https://epistemology.locals.com/upost/4873625/physics-needing-more-study2
https://epistemology.locals.com/upost/4873597/physics-needing-more-study
https://epistemology.locals.com/upost/4861830/all-salvatore-pais-papers-as-of-november-2023
https://epistemology.locals.com/upost/4810069/my-theory-on-papp-s-noble-gas-engine-physics
https://epistemology.locals.com/upost/3042392/archive-water-cavitation-info
https://epistemology.locals.com/upost/3004805/what-causes-water-cavitation