At the time of To Sleep in a Sea of Stars, humans had not yet found a way to directly manipulate gravity (although the possibility was theorized by physicists). Instead, they created pseudo-gravity by spinning their space stations and sections of their spaceships.
In comparison, the Jellies—using tech scavenged from the Old Ones—were able to increase or decrease the inertial resistance of mass by increasing or decreasing the energy potential of the spacetime fluid around their spaceships and space stations. This not only allowed their ships to accelerate far faster than human ships for a given amount of thrust, it also allowed them to create true artificial gravity. This, plus the fact that Jellies were used to an aquatic environment, meant that the interior of their spaceships tended to be laid out completely differently than those of human spaceships.
When communicating slower-than-light, humans in the time of To Sleep in a Sea of Stars used radios, lasers, and of course, sound. However, in order to send information between stars, the most common technology used were FTL transmissions, which could be broadcast from deeper in a gravity well than a Markov Bubble could be sustained. Of course, for the fastest possible (and thus the weakest) FTL transmissions, the signals need to be broadcast from an area of relatively flat space-time fabric, which in practical terms usually means somewhere in the outer parts of a solar system, far from any planet, star, or other significant source of gravity.
Jellies evolved in a watery environment, and what they called nearscent was their normal means of up-close, in-person communication. For longer-range communication, they would often combine scent with sound, and this was known as lowsound farscent. Later, this became their term for electromagnetic signals, such as radio waves or lasers. Just as humans converted electromagnetic signals into sound, Jellies converted them into scent.
As name implies, gecko pads helped the wearer cling to surfaces. They were commonly used on the bottom of skinsuits and boots intended for climbing or maneuvering in zero-g. The pads were covered with bristles around 5 μm in diameter and depended on van der Waals force for adhesion. Shear force was the limiting factor for maximal load but also provided the mechanism for release.
The psycho-mechanical joining of two or more brains accomplished by continual-beam synchronization of subject implants, which ensured agreement between intero-, extero-, and proprioceptive stimuli. Total exchange of prior sense memory was a common (though not required) part of establishing a hive mind. The effective range depended on signaling bandwidth and tolerance for lag. Many Entropists were joined to others with this tech. The largest recorded hive mind was forty-nine, but the experiment was short-lived, as participants experienced debilitating sensory overload.
Type of 3-D printer that utilized nanobots to produce complex shapes, machines, and—given the appropriate stock—biological structures such as muscles, organs, and seeds.
Nest of Transference
Jellies used this device to copy memories and basic brain structures from one body to another. It was also used to imprint stored personalities/memories onto a new body after the original individual died.
Pseudo-intelligences were programs capable of limited executive function. They seemed lifelike but lacked self-awareness, creativity, and the human ability for introspection. Despite their limitations, they proved immensely helpful in nearly every realm of human endeavor, from piloting ships to managing cities.
Hi-tech, general-purpose, skin-tight protective clothing that—with a helmet—could act as a spacesuit, diving equipment, and cold-weather gear. Skinsuits were standard human equipment for anyone in a hostile environment.