Tuesday, January 24, 2017

Early Steps in the Climb to Asymptotic Technology

A species which evolves to the beginnings of intelligence and tool use is on the pathway to having a civilization and to developing asymptotic technology, which is the final state of technical knowledge and capability. There are some huge changes in the civilization as it advances, and these stages have been separated by great alterations in the civilization, which we have termed grand transitions. These include the transition to hunting from gathering, to agriculture, to industrial capability, to robotics, and lastly to genetic technology. These should occur more and more rapidly, and be finished before the civilization took to the stars, if it chose to do so.

On the other end, the changes are slow. There is little communication of new ideas, and few involved in devising them. There is a question as to whether there are some barriers to technological growth that occur very early in the technology sequence, and also as to whether there are planetary conditions which would be involved in these barriers. If there were, and we on Earth developed large enough observatories to detect these planetary details, we might be able to filter out some worlds as capable of originating life but not of supporting its climb all the way to asymptotic technology.

Having grasping appendages is the key and final evolutionary change that kicks off the climb in technology. This could evolve as one of the side-steps that evolution can do, where there is one reason that leads to an evolutionary mutation, but then that mutation proves to be useful in a different task. Tree-climbing to escape predators or obtain food can be the driver for grasping appendages, and then they can enable tool use, where the tool is a stick or a stone or a vine. Once this side-step happens, the road to improved tools is opened up, and that is all that a species needs to grow its brain and dexterity together.

Obviously, the planet would have had to developed in such a way that these very primitive tools were available in the area where the species emerged. Sticks can be found which are already pointed, but if a point can be developed, it can be a much better hunting tool. This requires trees with long straight trunks and hard wood, plus some exposed smooth stone surfaces for grinding the points. There does not have to be many of this type of tree, as the stick can be re-used many times. Such a tool would make a difference in the type of animal that could be killed for food. On Earth, hardwood grows in many different forests around the world, meaning that it is not climate-dependent. Outcroppings happen everywhere, so this requirement would not be a barrier on any world with tectonics similar to this planet. It would not happen on a planet without continental formation, where the only surfaces were sand and dirt.

In the hundreds of millions of years it takes for land surfaces to have photosynthetic plants and mobile creatures to use their energy, if there is no vulcanism or continental formation, there would be little chance for the co-location of forests and exposed rock surfaces. Soil would form a covering layer, except where sand was brought in by ocean activity. Theories have not yet been developed about exo-planet continental formation, so it is not clear at this point if planets of Earth size would necessarily have tectonics. It is certainly possible to imagine a more homogeneous mantle and crust where vulcanism doesn’t occur, and where there is much less vertical variation. Alternatively, vulcanism could be confined to the polar regions.

One signature of large variations in vertical extent would be the existence of large oceans, as opposed to only multitudes of lakes and rivers over the whole planet. An ocean would be observable, clouds excepted, on a planet out to a hundred light years or so by a space-borne telescope of a kilometer diameter, and this might be Earth’s only clue as to the status of a found origin planet.

The next steps in tool-using might involve clubs, which are simply found objects, and sharp stones, which might originate as found objects, but might have to be made. Sharp stones serve as cutting tools, although shells are also thought to have been used for that purpose on Earth. Large, hard shells pretty much need an ocean to form and exposed rocks to be sharpened, so we are back to needing an ocean. Sharp stones also required exposed rocks, but of a particular type. Basalt can be given an edge, as can quartz, and obsidian. These rock can be naturally exposed, such as by running water. Flint can also be used. Flint is a sedimentary rock, meaning oceans once again. There seems to be no avoidance of the necessity for continental upthrust and oceans on any world which gives rise to an alien technological civilization. Without these, it doesn’t get started.

Non-human primates have been observed using stones as tools, so there is no requirement for the development of any human skills, such as speech, prior to the use of stone tools, and this means that brains can co-develop with stone tools, rather than having to precede them. On Earth, stone tools with manufactured cutting edges have been excavated from sites dated over two million years ago, which is another confirmation that creatures that get started on stone tool-using do not have to be developed to the degree of homo sapiens. It must be the opposite, that homo sapiens, and similarly capable alien species, develop via the use of stone tools.

The list of necessary geology does not stop with the need for certain types of stones being available. After stone tools, almost in recent times, pottery developed, needing clay. Clay is weathered rock of certain types, with particle sizes of the order of a micrometer or smaller. It is widely available, and again simply requires exposed rock and weathering by water. If stones for stone tools are available on an alien exo-planet, clay should also be, leading to the first manufactured products. There does not seem to be any obvious requirements other than continental upthrust and oceans necessary to allow a species to step over from pre-civilization to civilization.

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