Almost all the high technology of the Gundam world derives from one underlying scientific miracle - the wondrous discipline of Minovsky physics. This wide-ranging field of study is named after its pioneer, whose name has been variously given as Doctor T.Y. or Y.T. Minovsky. Though at first glance you might be inclined to write off the entire subject as a bunch of hokum, twenty years of earnest effort by Gundam creators and fans have given us a surprisingly coherent theory to account for the manifold mysteries of Minovsky physics.
The discoveries that lead to the field of Minovsky physics begin with an ambitious project to develop a practical nuclear fusion reactor. This effort is launched in UC 0047 by Side 3's Minovsky Physics Society, and after years of research Dr. Minovsky and his colleagues complete the Minovsky-Ionesco reactor. Unlike traditional fusion reactions, which emit neutron radiation that can only be shielded by several feet of concrete, the Minovsky-Ionesco reactor uses a "clean" fusion reaction that emits no neutrons:
2He3 + 1H2 -> 2He4 + p (energy released: 18.35 MeV)
The reaction uses a rare isotope of helium known as helium-3, which fuses with deuterium atoms to form normal helium. The reaction also emits a proton, a charged particle than can be easily contained with magnetic fields. The one problem with this process is that helium-3 is extremely rare; Earth has very little helium in its atmosphere, and helium-3 makes up only 1/700,000 of this amount. Though lunar soil has been found to contain large amounts of helium deposited by the solar wind, the Gundam world's fusion reactors rely on the constant supply of helium imported from the outer solar system by the Jupiter Energy Fleet.
In UC 0065, the researchers of the Minovsky Physics Society notice a strange electromagnetic wave effect within the Minovsky-Ionesco reactor that cannot be explained by conventional physics. Within a few years, they've identified the cause: a new elementary particle generated by the helium-3 reaction, which is named the Minovsky particle.
The Minovsky particle has near-zero rest mass - though, like any particle, its mass increases to reflect its potential or kinetic energy - and can carry either a positive or negative electrical charge. When scattered in open space or in the air, the repulsive forces between charged Minovsky particles cause them to spontaneously align into a regular lattice structure called an I-field. The I-field creates an interference effect, called the Minovsky effect, that blocks low-frequency electromagnetic waves such as radio and microwave transmissions - even infrared radiation is affected, though not blocked entirely. The I-field itself is invisible, and can be detected only by its effects.
With the rise to power of Sovereign Degwin Zabi and the creation of the Principality of Zeon, the Zeon military immediately seizes on the military applications of this discovery. In UC 0070, Zeon military researchers confirm that, by scattering large quantities of Minovsky particles, they can temporarily nullify radar and radio communications and reduce combat to visual range. Minovsky particle scattering is a standard feature of the Gundam world's space warships, though most mobile suits lack this capability.
In UC 0071, Zeon researchers create the super-compact Minovsky fusion reactor. Instead of the conventional magnetic field, this improved version of the Minovsky-Ionesco reactor uses an I-field to confine and compress the reactor fuel, triggering a fusion reaction. The Minovsky particles produced as a byproduct of the helium-3 fusion reaction are thus recycled to keep that reaction going. The Minovsky particles that form the I-field lattice also help catalyze the fusion reaction, in a process similar to the muon-catalyzed fusion investigated by real-world scientists during the 1950s. This super-efficient design is only a fifth as large as an equivalently powerful Minovsky-Ionesco reactor.
Other I-field Applications
Since it's made up of charged particles, the I-field is unable to permeate through metal, water, the Earth's surface, or other electrically conductive materials. Thus, at low altitudes it's possible to generate an I-field cushion between the underside of a vessel and the ground, yielding a gravity-countering buoyancy. This principle is used in the Minovsky craft system introduced during the One Year War and eventually made standard on all space warships, though it's not until decades later that the Minovsky craft system is miniaturized enough to be installed in mobile suits.
Another application of the I-field, and probably the one most familiar to the viewer, is the I-field barrier. This generates a dense I-field in the space surrounding the barrier generator, which can deflect the beam weapons derived from Minovsky physics. The barrier has no effect against lasers or against physical attacks such as missiles, and within the barrier's radius beam weapons function with their usual lethality.
Though the high power requirements and immense heat of the I-field barrier rule out its use on all but the most exceptional mobile suits, it's used by mobile armors such as the MA-08 Big Zam and the MRX-009 Psyco Gundam. Even in a full-sized mobile armor, the heat factor is still problematic, and the Big Zam is able to sustain the barrier for only 15 to 20 minutes. Since the basic principle of the I-field barrier is similar to that of the Minovsky craft system, it's relatively easy to combine the two systems, and a mobile armor with one of these gimmicks often has the other.
The magical art of Minovsky physics has one more trick up its sleeve. Due to the repulsive forces between positive and negative Minovsky particles, large amounts of energy are required to compress an I-field lattice. If enough energy is applied, and the I-field sufficiently compressed, the Minovsky particles ultimately fuse into massive, electrically neutral mega particles.
The energy used to create the mega particles is expressed as both mass and velocity. No longer subject to the electrical forces that maintain the I-field lattice, the particles burst out of the I-field. This stream of heavy, fast-moving particles, unlike a conventional charged-particle beam, cannot be deflected with magnetic fields. In UC 0070, Zeon researchers exploit this phenomenon to create the fearsome mega particle cannon.