Shield technology in various soft sci-fi settings is often pretty unexplained or inconsistent in it's capabilities, being left to fan-theories and other explanations, which even then are inconsistent or don't fit every circumstance. I intend to avoid this in the Felneyverse, so this page explains how shields in my science fiction settings work.

The "Shields" referred to are those in Rocket Redferne, Galactic Conquest and Teddy Bear World (invented entirely independently, but based on the same principles). In Insanity Please, the "barriers" they use are magical in nature and thus work differently. In less-serious superhero stories, heroes may also have "energy fields" etc that work in a different way.

What are shields?

Shields are used on various vehicles, but usually spaceships, to provide an extra layer of protection against impacts or energy weapons, preventing hull breaches or damage to vital systems. Shields can be "bubble shaped", but more often conform to the hull shape of a vessel, half a metre or so "above" the surface of the hull. Shields are usually seperated into multiple flat planes, and are generated by shield emitters. The earliest models of these were large domes that projected an ill-defined, circular shield that was thicker at the centre and thinned out at the edges. These are the kinds that will be seen in Teddy Bear Wars, as they are invented during the course of the story. Later shield generators, seen in Galactic Conquest, are much smaller and more numerous "dimples". Many of them combine to generate shields in hexagonal-shaped sections that fit together. These sections are usually combined into a larger "screen". Ships have multiple "screens" covering different angles of approach. Captains of large space combat vessels are trained to quickly turn their ships to present an undamaged screen to the enemy, if they lose one.

What shields protect against.

Shields act, essentially, as a wall of water, though with more density (or under more pressure). The harder something hits the "water", the more strongly it is resisted against. This allows slow-moving shuttles, fighters or other craft to dock with, or enter the hangars of, larger ships without those ships lowering their shields. Fast-moving objects, from single subatomic particles up to asteroids, railgun slugs or attacking enemy ships, are strongly resisted by the shields, and usually destroyed, or repelled.

Even the weakest shields on civilian spacecraft give near-total protection against gamma radiation, as the energy waves, travelling at the speed of light, completely anniahlate or repel themselves from the shield, causing it only negligible damage. This allows long-term space travel with complete safety from radiation. The more substantial (but still microscopic) micrometeroites are likewise no threat at all.

The larger and faster an obect is, the more damage it does to the shield as it anniahlates itself. The "water" of the shield is "boiled away", in effect, and needs to be replaced by the emitters. The more damage done to a shield, the longer the regeneration takes. If a shield collapses completely, a follow-up shot may destroy the emitters, and then a ship is in trouble! Railgun slugs, being made of a few kilogrammes of metal and travelling at a high percentage of the speed of light, can cause plenty of damage to a shield section, but as they are small and focus all their energy inwards, extremely accurate shooting is needed to get a follow-up shot to penetrate a ship's hull.

The main weapons used against shielded ships are referred to as "lasers". Actually they are more like a focused, narrow "cloud" of super-energetic plasma "packaged" among a synchronised burst of several laser beams. When these hit a shield segment, the lasers damage the one section, but the plasma spreads out in a large, incandescent blast and damages several other segments nearby too. Once a shield has collapsed this plasma can be used to incinerate a large number of shield emitters, whilst the lasers do more focused damage. They also have the advantage of travelling at only just under the speed of light, but the disadvantage of disspating as they travel.

Properties of Shields

Shields are essentially highly-focused, invisible, dense "clouds" of highly-charged particles. Numerous rare gases, found in only a few gas giants (which are, naturally, guarded strategic resources) are fed into shield systems, which charge and then emit them into a shield segment. This energy-intensive process is the second most power-hungry operation on combat vessels, the other being the main and FTL engines themselves. Any compromise or sabotage to a ship's core fusion reactors usually neccesitates a severe weakening of it's shields, to mere "navigational" (protection against only gamma rays and micrometeorites) status.

Within each shield itself, the particles are constantly flowing "upwards", away from the emitter, and then dropping back down to the bottom of the cloud more slowly, where they are pushed up again by transmitted energy from the emitter. Particles are gradually lost in this way, even if the shield has not been hit by anything, so the shield has to be constantly recharged at a low level. This high-energy "flow" in the direction of particles makes their protection almost entirely "one way". This allows for laser beams, plasma, railgun shots, missiles or fast-launching fighters to travel out from the ship with negligible interference from the shields at all. Only incoming objects get the full force of the shield.

Shields also have a frequency. These frequencies, a vitally-guarded intelligence secret, allow for shields on ships to "combine". Friendly fighters and shuttles with shields can synchronise themselves, the fighter or shuttle, approaching slowly enough, will actually "bud on" to the shields of the ship it is docking with, passing through them without harm. Other approaching ships or objects simply need to go very slowly, and the shield will allow them through without much resistance. Many attempts are, naturally, being made at methods of creating slow-moving weapons which will pass through an enemy ship's shield and detonate against it's hull. Such slow-moving weapons are usually easily countered by point-defence, though. Electronic countermeasures are also raised to near-perfection. Slow-moving "drones", attempting to pass through a ship's shields, are often just hijacked and turned back against their masters. Sneaky ways to negate shields usually rely on good old fashioned deception and pretending to be friendly.

History

Shields in the Gamma Universe were invented in 1984 by a race called the Olazons. When humanity first makes contact with the Galactic Government, in XX2175XX shields are already pretty much perfected. The ones seen in Galactic Conquest, despite it being over a century later, are not greatly improved in protective power, though are more compact and energy efficient. Think of lightbulbs - improvements made in lightbulbs haven't really made them brighter, they just waste less energy

In Teddy Bear World, shields are invented circa 8027, and only adopted on a few advanced and experimental military ships.

Advanced Shields

Quantum Shielding was referred to in Planet Felney once. It is some sort of improved version which allows a ship to fly through a star at FTL speeds... but has the unfortunate effect of causing unpredictable backwards time travel.

In the 24th century, the Humans have invented both double-layer and triple-layer shielding. This allows banks of emitters to emit multiple shields "through" one another. They share double-layer technology with other factions they are allied to, it is "synchronised" at high speed, much like the interrupter gear on First World War biplanes. Attempts by these factions to replicate the triple-layer shielding are unsuccessful, however, and it remains a closely-guarded secret, only employed on the Earth Emperors' flagship and a few other fleet command vessels.