Mohs Scale of Science Fiction Hardness/Physics Plus
Physics Plus: Stories in this class once again have multiple forms of Applied Phlebotinum, but in contrast to the prior class, the author aims to justify these creations with real and invented natural laws -- and these creations and others from the same laws will turn up again and again in new contexts.
- Schlock Mercenary is almost entirely plausible scientifically, although little of the theory appears in the work. Its placement is primarily due to limiting its Applied Phlebotinum to gravity manipulation(but not generation — ships are built around spheres of neutronium as sources of gravity to manipulate), taking it for granted that the process is as well developed as electronics, and playing the result to its natural conclusions; ubiquitous Flight, Deflector Shields, traversable wormholes (one example which justifies a Time Travel storyline), and quantum teleportation.
- The Uplift series, by David Brin: Hard science mixed with a lot of Imported Alien Phlebotinum to make one of the 'hardest' of the Space Operas, a sub-genre that is usually very 'soft'. Although, in fairness, there are really two Uplift series. The first trilogy is vastly harder than the second, which degenerates into pure magic alien squishiness by the end -- including aliens wishing their enemies out of existence through reality warping.
- The Pentagon War has the Quantum Confinement-and-Constriction field, the Magnetic Focuser, Hyper Holes, and a gizmo whose very existence flies in the face of Einsteinian relativity. It tries to apply these consistently, however, and is careful not to break established laws like Conservation of Momentum or the Laws of Thermodynamics.
- The 2003 reboot Battlestar Galactica series seems to fall in this category. Cylon resurrection is never really explained, but spacecraft movement seems to follow Real Life physics and the FTL jump drive's limitations are applied more-or-less consistently.
- Arguably Sword of the Stars. FTL methods are based on esoteric if not outright fictional scientific theories like the so-called "Menisceal Principle", high-end techs include weaponized sub-atomic particle beams and there are bevies of Precursors-leftover tech that defies current scientific understanding, but much is also feasibly extended from existing scientific knowledge. To its credit, ships are much more modestly sized than in most other series; even the ~800m Leviathans, monstrous by the series's standards, fail to break the kilometre mark common to many other series' capital craft, and definitely are far from the multi-kilometre hulks of higher-end/softer works. However the first game goes to the opposite extreme with FTL capable destroyers that are smaller than Real Life space shuttles.
- The Liir have no explanation for how their "stutter" drive teleports short distances every few milliseconds, until the second game where the Suul'ka are capable of psionically folding space.
- The Mass Effect series possesses mostly well-researched technology, with an in-game Codex that goes into detail about the science and technology of the setting. For the most part, the technology is presented consistently, and the physics are kept very close to reality, barring the use of element zero, which produces the eponymous "mass effect" which allows for the increase or decrease of mass, and subsequently allows for the creation and manipulation of gravity fields. Most of the fantastic elements of the setting stem from the use of mass effect fields, i.e. Faster-Than-Light Travel, Artificial Gravity, Deflector Shields, and Stealth in Space. There are also the trappings of more fanciful and softer elements of science fiction, like Hard Light, or psionics which are either outgrowths of mass effect technology (i.e. illuminated mass effect fields for Hard Light, naturally developing element zero nodes growing in living tissue due to pre-natal exposure for psionics, etc.) There are examples of unusual biology that allow for mind-reading or manipulation, i.e.asari physiology allows for them to "meld" their nervous systems with others', and in the rachni case they emit sound waves to communicate and their queens can puppet bodies that are close to death by manipulating their nervous system. The only technologies that are not fully explained and explored are those of the Reapers, be it indoctrination, their "huskification" process, their ability to "assume direct control", or how they construct other Reapers from the "processed" bodies of organics. Because of the Lovecraftian elements of the setting, this is likely deliberate. In addition, both the Reapers and Collectors possess energy weapons, which are impractical on a personal scale for any other species and only used as point defences on starships and large installations, but this is another point that can be put down to Sufficiently Advanced Aliens since nothing about them is impossible with current physics, just current power sources and reliability issues.
- As an addendum to the above: The ingame Codex clearly points out that Hard Light isn't actually hard - it's just a holographic user interface, offering no resistance and interacted with using special gloves or finger implants, which simulate the resistance that would be present if the display were not just a hologram. Mass Effect 3 has an "omniblade" which appears to be a holographic blade, but is in reality a transparent and disposable monomolecular knife created by a wrist-mounted omnitool's micro-manufacturing plant.
- Another addendum, the "energy weapon" used by Sovereign at the end of Mass Effect was revealed (via the codex in Mass Effect 2) to be a high tech fire hose. It used a mass effect field to shoot out liquid of iron, uranium and other heavy metals out at speeds similar to other main ship guns.
- The harder end of the scale within Star Trek may fall in here (primarily Star Trek: The Next Generation), with the rest being one point lower.
- Andromeda, a series based on one of Gene Roddenberry's ideas that he never used, is a bit harder than "Trek", there's no transporters and most of the Andromeda Ascendant's weapons are fairly plausible (relativistic missiles, anti-proton cannons, point-defense lasers...), but its maneuverability and acceleration require extensive use of Artificial Gravity and the only method of Faster-Than-Light Travel is slipstream drive. A form of hyperdrive where the ship uses antigravity to reduce its mass to near zero and then travels along "strings" connecting different solar systems, along the way navigators have to intuit what paths they take and organic pilots are right about 99.7% of the time due to the "ability of organic observers to collapse wave function probabilities."
- The later seasons border on fantasy with sapient stars and aliens who can fold space at will.
- Starship Troopers features FTL travel, but this is handwaved as an excuse to allow for the main Bug War plotline. Other elements (such as the famous Powered Armor) are speculative, but certainly within the realm of possibility. The book is also vague on whether humans can survive on alien planets without protective measures of some kind. The main purpose of the work is to be didactic, not to get the science 100% right.
- Divergence Eve features FTL Travel, but isn't the main feature of the story. The main feature is about the wormholes allowing for FTL Travel (a second kind) via an alternative dimension, the fact that a now extinct alien race has overused said wormholes and caused a planet to internally collapse. Not only this, there's various DNA experiments with are more or less hand-waved away (compared to the two versions of FTL Travel, that are explained with detail) and the ability to download data from an alternative universe/dimension straight into a human's brain.
- The Five Star Stories goes to great lengths to justify its Mortar Headds, but besides that, it has a lot of imaginary biological laws for both the 'evolved' Jokerians and the synthetic Fatimas
- The Whateley Universe has superheroes, but explains everything through the science of 'pattern theory'. There's occasional diversions to explain things like Giant-man style giants and why they don't have problems with the square-cube law and why they don't overheat (in fact, they overcool and Matterhorn accrues 'snow' on his shoulders as he stays big) and why they have trouble interacting with our 3-D world as they get larger and larger. Giant humanoid robots don't work, for all the real-world reasons, although inventors at Whateley Academy are still trying. The implications of Phase's density-changing (actually, moving through other dimensions of our reality) power keep being revealed, and he still has troubles caused by the Law od Conservation of Momentum and the Law of Conservation of Angular Momentum.