It has been argued that the Kardashev scale is wrong; advanced civilizations will make progress by being more efficient or using more information or managing the entropy they produce, resulting in using less energy. Ants are more efficient as a civilization than humans. Ants as a civilization are not more advanced than Humans. The counterexample to the idea that the Kardashev scale is wrong to imply that a civilization which uses more energy is more advanced exists in every backyard on Earth. One civilization uses a lot of information and rules the solar system. The other does not.
The idea of the Kardashev scale is that a civilization will grow through three fundamental levels of energy consumption.
Level 1 is a civilization that consumes as much energy as its star would radiate onto the surface of its planet. For a planet that is habitable with water on the surface, that is going to be a broadly similar amount of energy. On this scale, humans are about 0.7, with garden ants being like a 0.001 and Beavers being a 0.01. For the sake of this scale, we are vague and broad about what we mean by civilization. A collection of creatures of the same species cooperatively living and modifying their environment in an intentional way is a civilization. So a single-celled organism called slime growing on a log is not a civilization. Yet multi-celled creatures that could shapeshift and build things using tools, while resembling a pool of organic liquid, would be. (Gif of a founder from Star Trek DS9).
Level 2 is a civilization that consumes all the energy their star produces. They have somehow fully harnessed all their star’s output. This would vary wildly between a Sun-like star and a smaller, longer-lived red dwarf. However, for any civilization, this energy source is such an obvious one. Freely available nuclear fusion is going on all the time. One way or the other, a civilization would harness this. The classic example is with a solid Dyson sphere around a single star. Reality would be swarms of space-based, solar-powered infrastructure orbiting freely around a set of nearby stars. Stars like this would appear to be anomalously dim
Level 3 is a civilization that harnesses a galaxy of stars. So level 2, copy-pasting their strategy over a whole galaxy. Hypothetically, there can be higher levels, but these are the classic ones on the Kardashev scale.
The power of this categorization is it links civilization with all its complexity to a fundamental physical quantity we can observe at a distance. Energy consumption. We can observe solar power being turned into infrared waste heat. IF we observe that going on in a way we cannot explain naturally, then it is a techno signature.
The basic assumption underlying all of this is that a civilization will use more power as it advances. The counter to this is that human civilization tends to become more efficient as it becomes more advanced.
How can we quantify efficiency? This would be hard to observe at astronomical distances, but the way we could do this is with TIME.
In physics, there exists a quantity called action. Usually denoted with an S. Action is Energy Time. Action, in terms of what an intelligent being can do, can be thought of as follows. We have a fixed lifetime. If we have more access to more energy, we can take more Action…. We can do more things.
An ant colony can only harness the muscle power it can get from the food it can gather (or in some cases farm, as some species engage in agriculture). That is. They can only do what their muscles allow them to do. They can construct impressive structures with just that amount of energy. Each ant must spend all its day on bare survival so that a few can be soldiers, and one can reproduce.
A beaver dam full of beavers working together can harness the power of water to engineer and modify their environment to their advantage. Arguably, the aquatic plants they eat, which grow in the ponds or lakes their dams create, are an agricultural product. This frees them to spend the rest of their time relaxing after improving and repairing their dam.
Meanwhile, human beings working together have made it possible for us to use crystals of silicon with electricity flowing through tiny impurities in those crystals to process information. We can do this on remote space craft, or flying through the sky, or deep under the sea. We can harness the power of fire in our cars' engines to get the fried meat of another animal to eat. Then spend the rest of our time thinking about whatever suits our fancy.
Through our machinery, and our mastery of energy, we can get a lot more done. Any species would want to be able to get more done in less time, so they can get more done during our limited life spans.
This may not be the most thermally efficient way to get things done. Taking one million years to construct a building may be the way to go if we want to save energy. This would result in less energy usage BUT less getting done and hence actually be less TIME efficient.
They can bite and sting us; we can do this to them.
It is easy to see which civilization is more advanced on balance.
