Megastructures
Info
All text is from Wikipedia.
Planetary scale
A Bishop Ring , Halo, or Orbital is a space habitat similar to but much smaller than a Niven Ring. Instead of being centered on a star, it is in orbit around the star and its diameter is typically on the order of magnitude of a planet. By tilting the ring relative to its orbit, the inner surface would experience a nearly conventional day and night cycle. Due to its enormous scale, the habitat would not need to be fully enclosed like the Stanford Torus , instead its atmosphere would be retained solely by centripetal gravity and side walls, allowing an open sky.
Stellar scale
Dyson Sphere
A Dyson sphere (also known as a Dyson shell) refers to a structure or mass of orbiting objects that completely surrounds a star to make full use of its solar energy.
Dyson swarm
A Dyson swarm is a Dyson sphere made up of separately orbiting elements (including large habitats) rather than a single continuous shell.
Dyson bubble
A Dyson bubble is a Dyson sphere in which the individual elements are statites, non-orbital objects held aloft by the pressure of sunlight.
Matrioshka brain
A Matrioshka brain is a collection of multiple Concentric Dyson Spheres which make use of star’s energy for computing.
Alderson disk
The Alderson disk is a theoretical structure in the shape of a disk, whose outer radius is equivalent to the orbit of Mars or Jupiter and whose thickness is several thousand miles. A civilization could live on either side, held by the gravity of the disk and still receive sunlight from a star bobbing up and down in the middle of the disk.
Stellar engine
A Stellar engine either uses the temperature difference between a star and interstellar space to extract energy or serves as a Shkadov thruster.
Shkadov thruster
Topopolis
Topopolis (also known as Cosmic Spaghetti) is a large tube that rotates to provide artificial gravity.
Ringworld
A Ringworld (or Niven Ring) is an artificial ring encircling a star, rotating faster than orbital velocity to create artificial gravity on its inner surface. A non-rotating variant is a transparent ring of breathable gas, creating a continuous microgravity environment around the star, as in the eponymous Smoke Ring.