A topopolis is a proposed tube-shaped
space habitat
A space habitat (also called a space settlement, space colony, spacestead, space city, orbital habitat, orbital settlement, orbital colony, orbital stead or orbital city) is a more advanced form of living quarters than a space station or habit ...
, rotating to produce
artificial gravity
Artificial gravity is the creation of an inertial force that mimics the effects of a gravitational force, usually by rotation.
Artificial gravity, or rotational gravity, is thus the appearance of a centrifugal force in a rotating frame of r ...
via
centrifugal force
In Newtonian mechanics, the centrifugal force is an inertial force (also called a "fictitious" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It is directed away from an axis which is paralle ...
on the inner surface, which is extended into a loop around the local planet or star. The concept was invented by writer
Patrick Gunkel.
Varieties of topopolises and similar fictional structures
A topopolis has been compared to an
O'Neill cylinder
An O'Neill cylinder (also called an O'Neill colony) is a space settlement concept proposed by American physicist Gerard K. O'Neill in his 1976 book '' The High Frontier: Human Colonies in Space''. O'Neill proposed the colonization of space for th ...
, or a
McKendree cylinder
A McKendree cylinder is a type of hypothetical rotating space habitat originally proposed at NASA's Turning Goals into Reality conference in 2000 by NASA engineer Tom McKendree. As with other space habitat designs, the cylinder would spin to pr ...
, that has been extended in length so that it encircles a
star
A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...
.
A “normal” topopolis would be hundreds of millions of miles/kilometers long and at least several miles (kilometers) in diameter.
Topopoles can be looped several times around the local star, in a geometric figure known as a
torus knot
In knot theory, a torus knot is a special kind of knot that lies on the surface of an unknotted torus in R3. Similarly, a torus link is a link which lies on the surface of a torus in the same way. Each torus knot is specified by a pair of cop ...
. Topopolises are also called cosmic spaghetti.
A topopolis with big enough
diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for ...
could theoretically have multiple levels of concentric cylinders.
Larry Niven
Laurence van Cott Niven (; born April 30, 1938) is an American science fiction writer. His best-known works are ''Ringworld'' (1970), which received Hugo, Locus, Ditmar, and Nebula awards, and, with Jerry Pournelle, ''The Mote in God's Eye'' ...
(1974) mentioned the idea in a much-reprinted magazine article "
Bigger Than Worlds
"Bigger Than Worlds" is an essay by the American science fiction writer Larry Niven (born 1938). It was first published in March 1974 in Analog magazine, and has been anthologized in ''A Hole in Space'' (1974) and in '' Playgrounds of the Mind'' ( ...
".
[
]
Examples in novels
Iain M. Banks (2008)[ depicts a topopolis that loops its system star many times in various braidings, and houses trillions of sapient residents. The topopolis was so massive that stray gases from the system collected within the major spacing within the braids by gravitation alone, producing a slight atmosphere between the strands, that the author describes as a "haze".
]Dennis E. Taylor
Dennis E. Taylor is a Canadians, Canadian novelist and former programmer, computer programmer known for his large scale hard science fiction stories exploring the interaction between artificial intelligence and the human condition.
Wr ...
(2020)[ in the book ''Heaven’s River'' features an alien civilization inhabiting a topopolis.
]
See also
* Big dumb object
In discussion of science fiction, a Big Dumb Object (BDO) is any mysterious object, usually of extraterrestrial or unknown origin and immense power, in a story which generates an intense sense of wonder by its mere existence. To a certain extent, ...
* Ringworld
''Ringworld'' is a 1970 science fiction novel by Larry Niven, set in his Known Space universe and considered a classic of science fiction literature. ''Ringworld'' tells the story of Louis Wu and his companions on a mission to the Ringworld, a ...
References
External links
*
* {{cite web , url=http://www.orionsarm.com/eg-article/48ac37b0e82ba , title=Cableville, a fictional topopolis at Orion's Arm , website=OrionsArm.com
Megastructures
Fictional space stations