I was thinking about the (modified) Kardashev scale recently, the implications and problems with it.
The original Kardashev scale basically classifies civilizations according to their energy consumption; type 1 uses all the energy of their planet, type 2 uses all the energy of their solar system, and type 3 uses all the energy of their own galaxy. The extended scale goes further, to multiple galaxies, universe and multiverse.
The issues I’m seeing with this are, first, that advancement and energy use don’t necessarily have to be directly correlated. An example of this problem is the original SETI assumption that an advanced civilization will emit radio waves into the universe, which is how we can detect them. The basis for this assumption was the fact that our own civilization at that time used land-based radio and TV emitters that radiated most of their output into space, and, of course, the assumption was that any self-respecting civilization will emit at least as much as we do. However, within several decades that changed; first we shifted to satellite relayed TV, which uses focused low-energy signals relayed from orbit, and doesn’t disperse anything into space. Soon thereafter, we shifted to the Internet, which transmits either through the wires or through satellite relays, and also doesn’t disperse anything into space. Basically, the window in which we had an EM signature detectable from space was 50 years. Furthermore, I remember an analysis saying that our type of unfocused emissions becomes undetectable past 1 lightyear, because it drops below background noise. You would have to use very strong lasers or nukes to be detectable from greater distances. So, this shows us how narrow-minded the assumptions of people such as Carl Sagan can be; they think they are smart and they have it all figured out, but their assumptions don’t really age well. Expecting an advanced civilization to keep requiring more energy, which it would obtain by capturing natural resources, is about as smart as someone from the Victorian era expecting that an advanced civilization would have to keep burning coal.
The second issue continues along this line: why would an advanced civilization harvest energy from its planet, or its star? Why wouldn’t it, for instance, learn to create its own? There’s only as much energy you can get by trying to tap the planet’s core, and at that point it might make more sense to use nuclear energy to produce heat directly and in a more controlled manner. Also, instead of building a Dyson sphere to capture the entire solar output, with extreme expenditure of resources wasted on building it, wouldn’t it be better to just learn how to, I don’t know, tap into vacuum energy, or, even better, learn how to do things so efficiently that you don’t have to use so much energy, and still produce better results? I’m thinking cars and computers: what we have today is much better than what we had 50 years ago, and uses much less energy. If we extend this line of thought, as a civilization gets more advanced, it first learns how to do something at all, and then learns how to do it better and more efficiently. Advancement isn’t in using “more coal”, it’s in using coal first, and then learning how to use electricity, and using nuclear energy to produce electricity. More powerful computers don’t use faster hard disks; they use NVMe solid state storage. They don’t use a CPU clocked to 10 GHz, they use 32 cores each clocked at 3GHz. As we can see, expectations of linear evolution of technology don’t really match what we are seeing in reality. Our more advanced technology didn’t require more radio/TV broadcasting towers to encompass the globe; it required many local cell towers and their connection to the Internet. I’ve seen experimental technology that uses LED lights to transmit data, and I use Ethernet over powerline devices to create LAN connections in my home without requiring additional infrastructure, which means that, theoretically, the information carrier can blend into the background so completely, it would be completely undetectable unless you know exactly what you’re looking for. Also, a well insulated modern passive home can use less energy than a 20th century home, creating a false impression of a civilization going backwards on Kardashev scale. Also, a civilization that uses nuclear energy to produce electricity will have a drastic reduction in need for fossil fuels, and consequently a reduction in CO2 output. If someone measures technological advancement by CO2 output, on the assumption that more oxidative processes prove greater energy use and thus more advanced civilization, he will conclude that a nuclear civilization is going backwards. In fact, what if the need to tap into the natural resources doesn’t universally signify advancement, but only its initial stage where we haven’t yet figured out how to do it better? If we, theoretically speaking, learned how to convert any kind of matter into energy (I don’t know, by producing some kind of particle or a field that neutralizes the quark-gluon connections and results instant breakdown of nucleons into quark-gluon plasma, and almost immediately thereafter into energy), we could theoretically speaking obtain more energy, more efficiently, from a bag of dirt, than a Kardashev type 3 civilization from tapping all the stars in the Galaxy. The way into greater power isn’t, therefore, through linear expansion of less advanced technology, but through intellectual breakthroughs that make it possible for us to create more advanced technology, that does things better but differently. Also, space travel doesn’t really work by linearly expanding the Apollo programme, by building bigger chemical rockets. A breakthrough is needed, something along the lines of folding space, or the stars will remain forever out of our reach, and there’s nothing really interesting in the solar system anyway, which is why we didn’t really bother with it all that much.
So, it is my opinion that the Kardashev scale reflects the old 20th century way of thinking, and needs to be not expanded, but abandoned completely and replaced with something that actually reflects our present understanding of technological advancement.
For instance, Type 1 civilization learns to grow its own food, not relying on hunting and gathering, and produces its own materials, not relying on sticks, stones, leather and whatever is found in nature. We had Type 1 civilizations since early Holocene, with bronze age, agriculture and what not.
Type 2 civilization learns how to use scientific method and learns how to produce technology that uses physical laws in new ways, independent on what’s found in nature. Electromagnetic and nuclear energy, and using electricity and radio waves for long distance communication are examples of a type 2 civilization. We became a type 2 civilization somewhere in the 19th century.
Type 3 civilization goes further than that, into producing artificial thought, and artificial life. This means computers that perform logical operations and data processing, and genetic engineering that goes further than mere selection of desirable traits and cross-breeding, into designing life forms that are engineered to perform pre-defined tasks in pre-defined ways. We are at this point an early type 3 civilization.
Type 4 civilization is beyond our understanding at this point, because if we could actually understand it, we would be a type 4. I would guess that parting ways completely with anything that’s found in nature would be type 4, to the point where a type 4 civilization can rebuild the universe from the basic building blocks to its own physical body, erasing the distinction between physics, biology and technology.