main index




Topical Tropes

Other Categories

TV Tropes Org
Mohs: 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.


Anime and Manga
  • 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.
  • Gundam falls somewhere between this and "One Big Lie" depending on which incarnation of the franchise you're talking about. Some, like the original Mobile Suit Gundam and Gundam00, use vaguely plausible ideas with huge deviances, like Minovsky physics and Newtypes, having their own rules. Then there's G Gundam...

  • 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 far harder than the second, which ventures into much more fantastical science 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.
  • 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.
  • 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 of Conservation of Momentum and the Law of Conservation of Angular Momentum.
  • First Contact Is Bad for You takes place in 2051, so most technology in the book was at least emerging or theoretically plausible at the time of writing. However, there are signs of a long-extinct alien race and their leftover technology - little effort is made to explain them in scientific purposes.
  • The Honor Harrington book series: Space Is an Ocean, but the series demonstrates internal consistency, relies on only a couple pieces of "new" technology (gravity control methods and hyperspace bands; three, if you also include Treecats' telepathic abilities), mostly merely extending other pieces of current technology (medical science, nuclear fusion containment, lasers). Additionally, space combat is very three-dimensional and ship-to-ship engagements are often fought at fractional light-second distances (contrast the traditional Star Trek Starship Standoff).

Tabletop Game

  • 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.
  • 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.

Video Games
  • Since Command & Conquer has three different universes, each has a different place on the scale. Overall it can be placed here as it features time travel, portal-based FTL, electro guns and visible laser technology, stealth fields and many a Cool Tank as far as the humans are concerned (the alien Scrin are a little weirder). None the less it always explains its technologies with All There in the Manual material and never gives technologies additional abilities that are implausible, all the while drawing a lot from Zee Rust concepts and mid 20th century ideas.
  • 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 Precursor-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 kilometer mark common to many other series' capital craft, and definitely are far from the multi-kilometer 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.
  • Homeworld (excepting Cataclysm) fits in here as well, disregarding scale issues: while Faster-Than-Light Travel via hyperspace jumps is possible (treated as time-delayed quantum teleportation requiring massive amounts of energy) the technology is stated as reverse-engineered from Progenitor ships and not completely understood by most current galactic civlisations. Most other devices are either explained fully, suggested to be based on Real Life principles, or treated consistently.
    • Artificial gravity does exist without further explanation, however appears to require capital ship-sized systems to the extent that gravitic weapons and defenses are built with entire vessels around them.
    • Old School Dogfighting and Space Friction are justified as secondary plasma exhaust jets located in several locations on the ships' hulls.
    • Cryonics require extensive genetic modification to work properly and still do not guarantee success.
    • Weaponry is mostly based on mass-driver technology, be it Magnetic Weapons capable of firing metal and plasma or firearms using space-worthy propellant mixtures. Ion Beam Cannons are hinted to be stream-firing plasma armature railguns, ejecting ionised gas at relativistic speeds. Lasers are an exception, being visible pulse beams mounted as point defenses on larger vessels or projectile interception weapons on specialised fighter craft.
  • FTL: Faster Than Light has FTL (jumps only between set beacons, much more like a Portal Network), artificial gravity, Deflector Shields and teleporters. They have their own internally consistent set of rules that are sometimes exploited (teleporters work through shields, so there are weapons that teleport explosives to the enemy ship) and the other weapons are fairly realistic.


Back to Mohs Scale of Science Fiction Hardness.
World Of PhlebotinumMohs Scale of Science Fiction HardnessOne Big Lie

TV Tropes by TV Tropes Foundation, LLC is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
Permissions beyond the scope of this license may be available from
Privacy Policy