Wednesday, July 29, 2015

Solo Planets

Colonizing a planet probably costs an alien civilization a lot of money, in whatever measure they use to regulate their economy. It means a commitment of valuable resources that will leave the recycling loop, probably permanently, as if a ship is built, stripping it down and reusing the parts might well be done in space, rather than by dropping them down to the planet’s surface. It means energy will be expended in addition to the energy used to power the civilization. People or robots or intellos will devote their time to the task, instead of to the tasks of running the cities.

Both category 0 and category 1 alien civilizations have as one of their memes to colonize the galaxy, and both are looking for planets that are suitable. Both of them would like to do as many planets as possible within some time frame and with the minimum amount of resources needed. Alien civilizations learn early, within a few millennia, how to be efficient and how important it is to minimize waste and unrecyclable consumption. Otherwise they go out of business. Thus, a colonizer is trying to do the colonization of a planet as inexpensively as possible.

Some planets obviously will need much more expense than others. We call planets, sweet spot planets, if they are very close to the desired attributes of the final design for a colony. Some attributes are unchangeable, such as surface gravity, others are malleable, such as the ecology. Of the malleable ones, some take aeons to fix, which is no problem, others may take a comparatively short time, such as cleaning out an area of a hundred or so asteroids which have the potential to impact the target planet within a million years or so.

There is one other unique case that the colonizers will notice. What do they do when they find a planet which will indisputably evolve into a home world with creatures just like the colonizers, or rather, just like the colonizers were before they doctored up their own genes to improve themselves. They don’t have to do anything to it, as it will already become what they would have wanted it to. For zero expense, they achieve the same result.

They could look at their knowledge of the evolution of planets, just like their home world or very similar, and state when the various transitions will occur in the unassisted evolution of the planet. They know what will happen, and probabilistically speaking when it will, as probabilistic events are outside their omniscience. They would know a distribution of times for each of them to happen. They have a choice to make: try and speed up the stages of evolution on the planet, or use their resources on another planet that probably wouldn’t develop life or intelligent life, and make it happen there. If they can cut a hundred million years out of the evolutionary process, perhaps their decision will go one way. If they can cut only 10 million years out, perhaps another way. If they can cut a billion years out, yet a third way. Since we have not invested enough resources in the origin of life question, we cannot yet form an idea of how much time might be saved, nor of how much effort it is to change this time. If the effort is as simple as sending a small probe there with some cells that would be self-sufficient on the planet, and then dropping them into the ocean at some propitious spot, perhaps they would do it to speed up evolution even by a small amount.

For the purpose of discussing this type of planet more easily, let’s call any planet which will, with high probability, develop life and intelligent life on its own, if left unaided, a solo planet. This definition is broad, and is not exactly what some of the colonizers are looking for. Recall that category 0 and category 1a colonizers, those with the Columbus and the heritage memes, are interested in replicating their own ecology, that of their home planet, on their colonies. Category 1b on the other hand, with the warden meme, is interested in promoting life throughout the galaxy. Civilizations in the category 1b would look upon any solo planet and probably let it alone. Civiliztions in category 0 will eliminate any ecology that does not match theirs, unless it is a well-defended planet. Category 1a home planets will make the decision economically. They are interested in multiplying their home world through the galaxy, and if it is easier to find a sweet spot world elsewhere, without life or with a very early stage of life that is easily supplanted by their own, it is better that trying to eradicate life on a solo planet in a later stage of evolution.

This raises two more detailed questions. One is the question raised before: is there only one form of life that can evolve intelligent life-forms? If so, there would be no question of eradication. If it has life, it has life like the home world’s. The decisions that colonizers make are somewhat simpler. They have a speed-up question to ask, and that is all. They do not disturb what will happen as there is only one pathway to intelligent life, and a solo world, by definition, will develop it, barring some catastrophe. The colonizers might do something about potential catastrophes, but not to change the order of evolution that is already occurring on the solo planet.

The second question needs only be asked if the answer to the first one is no. If it is true that other forms of life can occur, that there are two of them at least, then the colonizers' decisions are more complex, and the categories split apart on some possible habitable worlds. When we say forms of life, we do not mean that butterflies have different colors on the new world, or that there are fish with different gill patterns, or any one of the more or less random details of particular species or genus’s are different. What constitutes a different life-form would be something drastic, such as the use of a chemical other than DNA for coding of control of cellular development, or the use of different amino acids for the four bases of the coding, or the coding scheme being with six bases per gene, instead of four. Alternatively, it might be using DNA as we know it, but life being solely chemotrophs, who somehow develop intelligence. It is not that the colonizers will eventually see the same large land animals as on their home planet, but that they may never see animals at all, only sea creatures.

Now it gets interesting. If there are different pathways to intelligent life, meaning different types of intelligent creatures, tool-using ones that can create a civilization and try for the stars, what causes the difference? Is it random chance, that during the time of the first batch of Great Filters, the unlikely event that occurred was of the fourth type, which led to chemotrophs, rather than the first type, which led to primates? If it is not random chance, was it some condition on the planet, either permanently or at some time in the evolutionary cycle? Was it the star type, being the luminosity and the metallicity? Here the higher or lower energy photons might have an effect, such as on the development of chlorophyll or a surrogate for photosynthesis? Was it the edge of the habitable zone that the planet was on, with near-boiling waters leading to a different form of more stable coding language, and cold waters leading to our kind? What it the amount of gravity on the planet, which affects what is in the atmosphere and also how hard the ocean to land transition might be? Was it the exposure of certain minerals under the sea, leading to the possibility of incorporating them in natural chemosynthesis? The list could certainly be expanded.

If there is a strong correlation between physical characteristics of the star and the planet with the type of life that develops, this colors the choices that a colonizer would have to make. A colonizer coming from a low-gravity planet around an M star might simply give up on a higher gravity planet around a G8 star. Their forms of life would simply not work. If this correlation is the case, category 0 and category 1a colonizers would be forced to form layers of colonies. Two completely separate life-forms might form and colonize the galaxy, but one only does their sweet spot planets, which are G8/high gravity planets, and the other does their sweet spot planets, which are M/low gravity planets. They might even talk to each other but not interfere with the other life-form’s activities in the least. It is like they are in two different galaxies, as far as colonization would go.

This means a lot for observables here on Earth. Communication might be happening between planets of each of the home worlds, but the communications would be of longer range, as the habitable planets are fewer and farther between. They would likely also be on different channels, meaning frequency band and encoding, although with completely separate agendas, it is conceivable they could form a pact to cut down on the number of channels. It looks like a lot of excitement for Earthlings in the next century or so when we develop the right listening apparatus.

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