Gravity

Gravity, or gravitation, is a natural phenomenon by which all things with mass or energy experience an attraction (or "gravitate" ) toward one another.

• A "Gravity", or "gee", is also the name of a standard Imperial metric measuring the force due to gravitation in terms of the acceleration it produces.
• G, the gravitational constant, is a physical constant related to the strength of the Force of Gravitation.

Description (Specifications)

Gravitation is a phenomenon caused by the presence of mass or energy within the structure of spacetime. Mass-energy will cause spacetime itself to bend, which in turn determines how that mass-energy will move along its worldline trajectory into the future. A mass in motion will give rise to a secondary gravitomagnetic field, and an accelerating mass will emit gravitomagnetic radiation. The basic Theory of Gravitation is described by the Theory of General Relativity.

Measurement

Planetary gravity measurements have used a number of different metrics, but those listed below have become increasingly standard. The Standard Imperial Unit of Acceleration is the "Gee", which was originally derived from the gravitational acceleration of Terra at sea level with a value of 9.81 m/s², but has since been metrically standardized by the Imperium with a value defined as exactly 10 m/s² = 1.0 kGal.

• The common Imperial abbreviation is g, g_n, or g₀ (note the italicization to distinguish it from "g", for "gram").
• The colloquialism "gee" is sometimes used for clarity as a unit abbreviation and also as a term for experienced gravitational acceleration forces.
• The symbol "G" is used for the Universal Gravitational Coupling Constant, as well as one of two unit-abbreviations for the Gauss, a measure of small magnetic flux. It is occasionally used (incorrectly) as a unit abbreviation for acceleration or gravities.
• The Eotvos (E) is an older measure of small Gravitational Gradient or Tidal Forces in Δg/unit-length.

Gravity Benchmarks & Metrics

Gravity
Category	gs
No Gravity	0.0
Microgravity:	0.01 g or less
Very Low Gravity:	0.02 to 0.10 g
Low Gravity:	0.011 to 0.49 g
Standard or Average Gravity:	0.50 to 1.49 g
High Gravity:	1.5 to 1.89 g
Very High Gravity:	1.90 to 2.00 g
Macrogravity:	2.01 g or higher (2.01-g+)
Black Hole	A Black Hole is an intense source of gravity.

Sophont Gravity Tolerance

All sophonts have an accustomed gravity based on their homeworld or the environment that they have spent the last year or more. Most can function with only minor difficulties at accustomed gravity plus ½ g, and major difficulty between additional ½ and 1g. Several technologies assist in gravity tolerance: Inertial Compensator, G-Suits, Acceleration Couches and deck orientation. Examples:

• Working crew (standing crew). Deck orientation: parallel to thrust, Inertial Compensator rating only.
• Working crew (standing crew).. Deck orientation: perpendicular to thrust, No Difficulty: Inertial Compensator plus accustomed gravity. Minor difficulty: Inertial Compensator plus accustomed gravity plus ½ g. Major difficulty: Inertial Compensator plus accustomed gravity plus 1g.
• Seated crew (Workstation or Acceleration Couch) Deck orientation: parallel to thrust, Inertial Compensator rating plus 2g. Minor difficulty: Inertial Compensator plus 3g. Major difficulty: Inertial Compensator plus 5g.
• Seated crew (Workstation or Acceleration Couch). Deck orientation: perpendicular to thrust, No Difficulty: Inertial Compensator plus accustomed gravity plus 2g. Minor difficulty: Inertial Compensator plus accustomed gravity plus 3Gs. Major difficulty: Inertial Compensator plus accustomed gravity plus 5g.
• Seated crew (Workstation or Acceleration Couch) and G-suit. Deck orientation: parallel to thrust, Inertial Compensator rating plus 3g. Minor difficulty: Inertial Compensator plus 4g. Major difficulty: Inertial Compensator plus 8g.
• Seated crew (Workstation or Acceleration Couch) and G-suit. Deck orientation: perpendicular to thrust, No Difficulty: Inertial Compensator plus accustomed gravity plus 3g. Minor difficulty: Inertial Compensator plus accustomed gravity plus 4g. Major difficulty: Inertial Compensator plus accustomed gravity plus 8g.

For accustomed gravity see Minor Non-Human Race and Minor Human Race, and for Major Races look to persons birth world.

• Solomani Humans: Accustomed gravity is 1g. Acceleration couch and G-suit 10 minutes at 6g. Acceleration couch and G-suit 1 minute at 10g.

History & Background (Dossier)

The history of the development of both the understanding and manipulation of the phenomenon of Gravitation and its spinoff pseudo-gravitational forces and effects is best understood through the development of its underlying basic Theory by the Ancient Solomani Physicist, Albert Einstein.

Gravity is typically conceptualized and understood by most sophont species by the end of the TL:1-3 technological epoch. By TL:4-6, gravity research becomes more theoretical culminating in prototype Gravity Control Technology by the end of TL:7-9 technological epoch.

Technological Overview of Gravity Control Technology

• Theoretical Gravity Control (TL:7-9) → Gravity Control Technology (TL:10-12) → Advanced Gravity Control Technology (TL:13-15) → Very Advanced Gravity Control Technology (TL:16-18)

Technological Stages of Gravity Control Technology

• TL:7-9: Gravity control is mostly theoretical at this stage although some societies are able to create large, unwieldy gravcraft, which nevertheless work. Starcraft G-Drives become more and more capable.
• TL:10-12: Gravity Control Technology is a foundation of interstellar period societies, which use it in large cities, for everyday transportation, in starships as Z-Drives, as scientific densitometers, and in a variety of other applications. This control of the force of gravity allows construction of vehicles, like the Air/Raft and G-Carrier, mapping of object mass through Densitometers, and safety equipment like the Grav Parachute.
  • While not often correlated by most people, historians have noted that the advent of practical fusion power plants is the result of applied gravitic compression of the fusionable fuels. Some mass-thrusters also rely on the gravitic compression of hydrogen to a near-fusion energy level. The ability to warp space-time and induce a jump is directly related to the control and understanding of gravitics. The Terran system failed to comprehend and use gravitics for many years, which delayed the Solomani expansion.
• TL:13-15: By TL:13-15, grav vehicles merge with orbital spacecraft, making for G-Drive Vehicles with near interplanetary capabilities, a step towards becoming true system craft. Gravity assisted material technologies yield Superdense Armor and Bonded Superdense Armor materials with protective qualities beyond anything previously imagined.
• TL:16-18: Projections from collapsed matter research suggest that Coherent Superdense Armor may be achievable. It is expected that Gravitic Control Technology will continue to advance in the near future becoming more efficient and miniaturized or possibly granting exponentially greater output.

See also

Universal world profile

§ == ( Please refer to the following AAB Library Data for more information: ) == §

• Main world
• Hex Number
• Universal World Profile
  • Starport (Sp)
  • Planetary Size (S)
  • Atmosphere (A)
  • Hydrosphere (H)
  • Population (P)
  • Government (G)
  • Law Level (L)
  • Tech Level (TL)
• Trade classification & Sophont Codes
• Importance Extension (Ix)
• Economic Extension (Ex)
• Cultural Extension (Cx)
• Nobility
• Bases
• Travel Zone
• PBG - Population, Belts, Giants
  • P: Population Multiplier
  • B: Belts
  • G: Gas Giants
• Worlds
• Allegiance Code
• Stellar Data

• COG Sequence
  • C: Climate
  • O: Orbit
  • G: Gravity

References

This list of sources was used by the Traveller Wiki Editorial Team and individual contributors to compose this article. Copyrighted material is used under license from Mongoose Publishing or by permission of the author. The page history lists all of the contributions.

• Frank Chadwick. Striker (Game Designers Workshop, 1981), B3-5,8,22.
• Frank Chadwick, Dave Nilsen. Fire, Fusion, & Steel (Game Designers Workshop, 1994), 75.
• Don Perrin. Starships (Imperium Games, 1996), 71.
• Martin Dougherty, Hunter Gordon. The Traveller's Handbook (QuikLink Interactive, 2002), 154.
• Robert O'Connor. Gravity and Acceleration at Freelance Traveller
• Marc Miller, Robert Eaglestone, Don McKinney. Worlds and Adventures (Far Future Enterprises, 2019), 251,287.
• Contributor: Master Scout and Former Naval Architect CRHensley of the Ministry of Science