Interstellar civilizationcan humans leave the solar system?

Whether humans can leave the solar system has no settled answer today. What has really happened is the 1969 Moon landing, and the change in particles measured by Voyager 1, which has left the reach of the solar wind and entered interstellar space. Mars bases, interstellar flight, Dyson spheres and the like are all marked "future" in the game. They are storylines the game imagines, not things that have happened.

This page keeps "real research" and "game speculation" apart.

Ten events imagined by the game

Everything below is game lore.

• 1969 · Moon landing: Humans set foot on another world for the first time.
• Future · Mars base: The first permanent settlement beyond Earth.
• Future · Kardashev Type I: Command of the energy of a whole planet.
• Future · Asteroid mining: Solar system resources are developed.
• Future · Interstellar flight: The first ship heads for Alpha Centauri.
• Future · Dyson sphere: A shell around a star collects all its energy.
• Future · Kardashev Type II: Command of the energy of a whole star.
• Future · Galactic colonization: Civilization spreads to hundreds of billions of stars.
• Future · Kardashev Type III: Command of the energy of a whole galaxy.
• 10¹⁰⁰ years · End of the universe: You have witnessed the life of one universe.

Real research: how to find other civilizations

Two physicists suggested using radio telescopes to listen for alien signals near the 21-cm frequency of hydrogen, which launched SETI (Cocconi and Morrison, Nature, 1959). A sufficiently advanced civilization might wrap its star, and we could find such civilizations by their anomalous infrared radiation. This is the Dyson sphere (Dyson, Science, 1960). Civilizations were classed by the energy they can use into planetary, stellar and galactic types (Kardashev, Soviet Astronomy, 1964). The game's Kardashev Types I, II and III borrow this classification.

There is also an uncomfortable question: if alien civilizations were common, they should long ago have filled the Milky Way. Michael Hart concluded from this that we may be the first (Hart, Quarterly Journal of the Royal Astronomical Society, 1975).

Real research: how to get out there

General relativity allows a "warp bubble" that compresses space ahead and stretches space behind, but it needs negative energy, which may not exist in reality (Alcubierre, Classical and Quantum Gravity, 1994). The game's rule is that faster-than-light travel is not allowed, so the warp drive is introduced here only as a piece of theoretical research. More realistic is the light sail: a ground-based laser array pushing a very light sail could accelerate a probe to one fifth of the speed of light (Lubin, Journal of the British Interplanetary Society, 2016).

What has actually gone out there is Voyager 1 (Stone et al., Science, 2013).

Real research: the end of the universe

Quantum effects make black holes radiate energy slowly. Black holes are not eternal and will eventually evaporate. The paper's title ends with a question mark: "Black hole explosions?" (Hawking, Nature, 1974). The fate of the universe trillions of years from now and beyond is that stars go out, protons may decay, and black holes finally evaporate (Adams and Laughlin, Reviews of Modern Physics, 1997). The search for dark matter has not reached a conclusion either. An experiment waiting for dark matter particles with 7 tonnes of liquid xenon about 1.5 km underground found no signal and set the strictest limits to date. What dark matter is, nobody knows yet (LZ Collaboration, Physical Review Letters, 2025).

Want to read the originals? Search these titles

• Cocconi and Morrison (1959): Searching for interstellar communications
• Dyson (1960): Search for artificial stellar sources of infrared radiation
• Kardashev (1964): Transmission of information by extraterrestrial civilizations
• Hart (1975): An explanation for the absence of extraterrestrials on Earth
• Alcubierre (1994): The warp drive: hyper-fast travel within general relativity
• Lubin (2016): A roadmap to interstellar flight
• Stone et al. (2013): Voyager 1 observes low-energy galactic cosmic rays in a region depleted of heliospheric ions
• Hawking (1974): Black hole explosions?
• Adams and Laughlin (1997): A dying universe: the long-term fate and evolution of astrophysical objects
• LZ Collaboration (2025): Dark matter search results from 4.2 tonne-years of exposure of the LUX-ZEPLIN (LZ) experiment

How the game shows it

In the game, the time range of the Interstellar civilization era is written "Future" and its resource is power. The generators are Fusion reactors, Orbital factories, Dyson rings and Interstellar colony ships, named in order of ever larger energy scale. In the game 1 light-year equals 1 hour of real time and there is no faster-than-light travel, so even interstellar flight has to be done at sublight speed, bit by bit.