Type I · A planet
1016 watts
Uses power on the scale of everything a planet has available. Weather, tides and sunlight are all within its reach.
Part one · The Goal
Catch the whole star.
A Type II civilization uses all the energy its star gives off. We use a tiny fraction of what reaches one planet. This site is about the distance between those two, and how it gets closed.
The Kardashev scale
Three rungs, each ten billion times the last
In 1964 the astronomer Nikolai Kardashev proposed ranking civilizations by one number: how much power they use. Carl Sagan later turned the three types into a smooth scale.
Type II · A star
1026 watts
Captures the full output of its star, most likely with a vast swarm of collectors in orbit. This is the goal the site is named for.
Type III · A galaxy
1036 watts
Commands the energy of a whole galaxy of stars. Nobody has a serious plan for this one yet.
Where we are
Humanity is about a Type 0.73
We run on roughly twenty trillion watts. On Sagan's scale that puts us most of the way to Type I, but each tenth of a type is ten times more power, so the remaining climb is still large.
Drag the slider to see what a given amount of power is worth.
Kardashev type
Power used1013.3 watts
Reading
Three books that started this
One pick each, with the reason and the catch. These are ordinary links. We do not earn a commission from them. If that changes, we will say so next to the link and on our affiliate disclosure page.
Carl Sagan · 1973
The Cosmic Connection
Why this one: the book where Sagan turns Kardashev's three types into the decimal scale used on this page.
The catch: it is fifty years old, and the space science shows its age.
Find it at Open LibraryMichio Kaku · 2011
Physics of the Future
Why this one: a readable tour of how a society might climb from Type 0 to Type I this century.
The catch: it is optimistic, and some of its near-term forecasts have already slipped.
Find it at Open LibraryVaclav Smil · 2017
Energy and Civilization: A History
Why this one: a careful history of how societies grow by capturing more power, from muscle and fire to fuels and electricity.
The catch: it is dense, and it stays on Earth. It will not walk you through a star-scale collector.
Find it at Open LibraryBest of the web
Worth leaving us for
We earn nothing from these. They are simply the best places to go deeper, including primary sources and the companies doing the flying.
- Our World in Data How much energy the world uses, charted.
- International Energy Agency A clear map of the world energy system, by source and use.
- SETI Institute The search for other civilizations on the scale.
- NASA Civil space flight, science missions, and public domain imagery.
- NASASpaceflight Independent reporting on launch vehicles, pads, and flight tests.
- ESA Europe's civil space agency.
- JPL NASA's jet propulsion laboratory, home to many robotic missions.
- SpaceX A commercial launch provider working on reusable rockets.
- Blue Origin A commercial launch provider, including heavy-lift plans.
- arXiv Open research papers, including astrophysics and energy.
Guides
Longer reads
Plain-language pages that go further than the sketches on this home page.
Guide
Capturing a star's energy
A Type II civilization would collect the energy of its star, most likely with a growing swarm of collectors. The physics, in plain language.
Guide
How the Kardashev scale works
The Kardashev scale ranks civilizations by the power they use. Here is the original three-rung idea, Sagan's decimal formula, and what a tenth of a type means.
Guide
What is a Type II civilization?
A Type II civilization uses the energy of its star. Here is what that means, where the idea came from, and why it is a goal rather than a schedule.
Guide
Where humanity sits on the scale
Humanity is about a Type 0.73, using roughly twenty trillion watts. Here is what that number is based on, and why the remaining climb is still large.
The bigger story
Five things it takes to get there
Each part of the climb has its own site. Start with whichever you care about most.
01 · You are hereThe GoalEnergy and the Kardashev scale
02 · Robot MotionThe HandsRobots that do the building
03 · Sentient CloudThe MindArtificial intelligence that runs it
04 · ComingThe PlaceLaunch, the Moon and beyond
05 · ComingThe PeopleLiving long enough to see it
Kardashev IIThe ScoreLive numbers and milestonesA couple of shops
Places to start, if you want them
These are ordinary links, not a storefront. We do not earn a commission from them. If that changes, we will say so next to the link and on our affiliate disclosure page. These are shops, not reviews, and not a claim that we bought or tested the goods.
- High Point Scientific A large U.S. retailer of telescopes and astronomy gear.
- Official SpaceX Store The company store for shirts, models, and mission merch.