Energy Emissions and Civilization Types

Galaxy HEEC map
Image from Dagon
High energy emission civilisations in the Milky Way galaxy

The concept of the Kardaschev scale dates back to the Information Age of Old Earth. This scale classifies civilisations by the amount of energy consumed compared to the energy emitted by the local star, and the amount intercepted by the local planet. In fact this classification has not been found to be very useful in practice, as most civilisations so far discovered have been lower than Kardaschev Type I. What is more, those civilisations which do have energy budgets exceeding the entire available energy of a single planet seldom use that amount in a single location but gather and use it across a number of worlds and habitats. Likewise, civilizations that employ energies equal to the output of a single star are usually distributed across dozens or hundreds of star systems rather than employing the energies of a single source.

A comprehensive catalog of distant civilisations has been drawn up over many millennia during the on-going Search for Non-terragen Intelligence. There are no Type III civilisations yet known in the local Supercluster, apart front the Leviathan (as described in the Triangulum Transmission) which seems to be an example of a civilisation which has converted its entire galaxy into an intergalactic vessel. In an effort to classify the known and detected civilisations purely on their observed emissions the Energy Emission Scale has been devised.

Null Energy Emission Civilizations (NEECs)

Civilizations without an energy output sufficient to be detectable above the background emissions of their native habitat. Agricultural Age or early Industrial Age civilizations on Old Earth or To'ul'h would be considered NEECs by modern experts. A great many have already been found inside the Terragen sphere. By definition none are known outside the Terragen sphere due to the difficulty of detection, but it is considered likely that they outnumber energy emitting civilizations by two or more orders of magnitude. Possibly this category is extremely diverse. Sophonts or even transapient civilizations might emit no detectable energy for a wide variety of reasons. They may be non-technological, low technological, or post-technological species. They might, on the other hand, be Hiders, using advanced sophont-level technologies or even clarketech devices to conceal their energy signatures. Some Muuh informants have implied that many advanced civilizations have taken this path. The motivations for such a strategy are a matter for conjecture, and in practice there are likely several explanations rather than just one. A large segment of the galaxy counterspinward of the Terragen sphere is either empty of sophont life or occupied solely by NEECs.

Low Energy Emission Civilizations (LEECs)

Energy emissions well above those of the natural environment, but difficult to detect at any great distance. Information Age civilization on Old Earth would have been a LEEC by modern standards; the Cthonids were a LEEC at the time of contact. LEECs are very numerous; their projected total for the galaxy is some thousands or tens of thousands based on those discovered within the Terragen sphere at close range or by careful analysis of Argus Array data. As with null emission civilizations, it is believed that this is a very diverse group.

Medium Energy Emission Civilizations (MEECs)

Of these, more than 140 have been discovered in the Milky Way galaxy, although around a quarter of these have disappeared over the last ten thousand years. Several thousand have been detected in other galaxies. There has been indirect contact by e-m transmissions with five of the closest examples outside the Terragen Sphere.

Interplanetary Age Terragens would have been classified as equal to a MEEC. These civilisations are generally somewhere between Kardaschev type I and II levels, sometimes using less, and sometimes considerably more than all the energy available on a single planet. The total detectable emission by such a civilisation can be considerable, but generally quite diffuse. Extensive though they are, the Muuh and Soft One civilizations are MEECs, as the emissions from any one system are not particularly strong.

High Energy Emission Civilizations (HEECs)

Extreme emissions such as those associated with the modern Terragen Sphere. There are seven such sources in the Milky Way, and Meistersingers may be associated with three of them. The Triangulum Transmission describes an extragalactic HEEC. None but the Meistersingers have made contact, and possibly no others have yet received the wave front of Terragen transmissions and emissions. These civilisations all control and emit much more energy than a hypothetical Kardaschev type II civilisation, but each is distributed over thousands of stars. Once a civilisation starts to colonise nearby stars successfully, it may exceed the energy use of a Kardashev type II civilisation quite rapidly, even if the inhabitants do not build Dyson swarms.

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Development Notes
Text by Stephen Inniss and Steve Bowers
Initially published on 26 June 2006.