Gravity in 2194

Gravity is a universal phenomenon, but it is also a weak one. The entire cosmos is permeated by it and the structures it sculpts, but for humans, living in human scales of time and space, most of the universe is flat, motionless and fundamentally different from the planet they once called home.

Life without Gravity

Health

Humans weren’t designed for space. Without the need for the body to work constantly against its own weight, muscles atrophy, bones lose calcium and fluids redistribute to the upper body. The brain, used to living in a world of up and down, becomes disoriented. People adapting to microgravity environments often spend days suffering from Space Adaption Syndrome or ‘space sickness’, which ranges in symptoms from nausea and disorientation to vomiting and intense discomfort. People incapacitated by space sickness are said to have ‘gone Garn’, after US senator James Garn, one of the most severe cases on record.

Thankfully for the modern space traveller, humans have been flying in space almost as long as they have been flying in atmosphere, and the problems are largely solved. The ‘space pill’ has been cheaply available since the early days of mass space tourism in the 21st century, and a daily regime limits bodily atrophy and space sickness. Consumers are warned to take a full supply with spares, however, as ceasing to take them causes the symptoms to return with a vengeance. Frequent space travellers also own a ‘g-suit’, a set of clothing designed to counter cardiovascular problems, though unlike the fanciful future fashion of the Solar Era such articles are typically worn under more conventional clothes. However, even with all these advancements the very old, the very young and the infirm are strongly advised against frequent space travel.

The only permanent solution to the health issues of microgravity is to alter the body itself. Many transgenic templates available today contain countermeasures to muscle and bone atrophy, and are designed to adapt to different gravities quickly and without complaint. Some heavily altered communities have gone further, with such alterations as turning feet into grasping tools and optimising brain structures for directionless environments, but these endeavours are rare and beyond the scope of this article.

Artificial Gravity

Of course, the most straightforward solution to lack of gravity is to make your own.

Spin Gravity

Centrifugal force has been the dominant means of emulating gravity since the mid-21st century. However, physical and engineering realities limit its use.

Rotating systems are not completely equivalent to gravity. Even minor motion in a spin-gravitated craft can cause disorientation and nausea due to effects on fluids in the body, and current pharmacutical treatments have only a limited ability to counteract this. Ordinary humans are advised against movement under more than 1 RPM unaided. Drugs, modifications or simple grit and experience can as much as triple this figure, but it remains the limit for the majority of civilian applications.

To achieve a circumference gravity of 1g with 1 RPM requires almost a kilometre of radius, well beyond any modern human spacecraft. Most civilian ships operate at lesser gravities, as even minor gravity is enough to mitigate space sickness and keep liquids and objects under control. The usual standards are 'half standard' (1/2 g), 'Mars standard' (1/3 g) and 'lunar standard' (1/6 g), with proportionate decreases in radius. Even a lunar standard 160m ring is impractically large for ships in dock at a space station however, and most ships are built with their spin sections in two or three retractable segments, that are extended during flight. Others, especially larger craft, communicate passengers and supplies exclusively through shuttles rather than physically connecting with a dock.

Static installations are another story. Without the need to deal with changing stresses, they can be built much larger than mobile vessels, and so fully-scaled 1g rings are not uncommon to find attached to the largest star ports. Space colonies are larger still, many half a dozen kilometres from axis to edge or more.

Pseudogravity

For years, 'artificial gravity' of the more sophisticated sort, that emulates a spacecraft standing on dry ground, was the domain of science fiction, added to provide a little technological zest to stories set in the near or far future.

Independently developed by scientists from SIYAN and the People's Republic of China shortly before the War, 'Pseudogravity' as it is known allows the exertion of mass-scaled force throughout a large area, provided your projectors are anchored strongly enough to withstand the reaction force. Unfortunately for space travellers, present pseudogravity projectors are large, clumsy and extremely power hungry, making them unsuitable for anything but large space stations operated by governments or wealthy companies. Miniaturisation concepts are on paper in many universities, but expected at least 20 years away from commercial viability. Despite these obstacles, Yangtze Shipping has announced plans for the Zijin Cheng, an enormous luxury cruise liner that would incorporate pseudogravity technology as well as the entertainments it makes possible, such as a small physical golf course.

It should be noted that pseudogravity does not actually use the gravitational force, instead making use of the Waldzell effect. Gravity is an extremely weak force that has so far eluded practical application, and genuine manipulation of geometry remains the preserve of the sophisticated and almost totally opaque machinery of the Posthumans. Also important to note is that pseudogravity is as bound by conservation of energy as any other technology - accelerating objects puts a strain on the power systems, and if too much mass is in the field the acceleration will diminish and become uneven.