Stellar engine
A stellar engine is a megastructure that uses a star's own energy to push the star, planets and all, across the galaxy. One racing faster than nature normally manages could give itself away.
A civilisation that outlives its star has to move, and a star passing too close is a reason to move sooner. A stellar engine would take the whole system along. A curved mirror on one side of the Sun would shift it just 0.03 light-years in a million years; an active design would cover 50 light-years in the same time. At their best, engines could reach speeds nature almost never gives a star, so surveys of the fastest stars double as a search for them.
Sources
- Lingam & Loeb, Constraints on the abundance of 0.01 c stellar engines in the Milky Way (arXiv)
- Vidal, The Spider Stellar Engine (arXiv)
- Forgan, On the Possibility of Detecting Class A Stellar Engines Using Exoplanet Transit Curves (arXiv)
- Centauri Dreams, Moving a Civilization: The Caplan Thruster
- Centauri Dreams, Moving Stars: The Shkadov Thruster
Read next
- Fermi paradoxThe Fermi paradox: life elsewhere looks likely, yet the universe we observe looks empty. Enrico Fermi, whose name it carries, never published a word about it.
- Kardashev scaleThe Kardashev scale ranks civilizations by the power they control: Type I about Earth's own, Type II a star's, Type III a galaxy's. By Kardashev's own threshold, humanity is past Type I.
- XenobotsXenobots are living machines built from frog embryo cells to shapes designed by AI. Set among loose cells, they shove them into piles that grow into new xenobots.
