Thursday, September 01, 2011

Using the Evolution of Software as a Model for Astrobiologists

I just finished reading First Contact – Scientific Breakthroughs in the Hunt for Life Beyond Earth (2011) by Marc Kaufman, which takes a slightly different approach to exploring the fascinating world of astrobiology than do most other popular books on the subject, because it is written in a narrative form, and describes the author’s worldwide adventures in seeking out the fascinating stories behind the work of many of today’s researchers actively working on the forefronts of the relatively new science of astrobiology. The other unique thing about First Contact is that the author showcases the work of some investigators on the cutting edge, who think we may have already detected extraterrestrial life, especially on Mars or perhaps even in distant star systems. Kaufman also maintains that it is important for researchers in astrobiology to go beyond the narrow confines of the definition of life that was unofficially defined in a 1994 NASA workshop as “a self-sustaining chemical system with the capacity to evolve in a Darwinian manner”, and that will be the subject of this posting from a softwarephysical perspective. Like the researchers currently working on the origin of life on Earth, the astrobiologists are confronted with a similar problem, namely, that they only have one example of life on Earth with which to work, and this limitation has had a tendency to focus attention within the field upon searching for Earth-like carbon-based life forms only. Softwarephysics would suggest that, since both carbon-based life forms and software are both forms of self-replicating information, the astrobiologists should expand their horizons a bit and concentrate more on searching for self-replicating information within the Universe, rather than solely focusing upon carbon-based life forms. Certainly the origin and evolution of software on Earth over the past 70 years, ever since Konrad Zuse cranked up his Z3 computer in May of 1941, provides an excellent model for the origin and evolution of all forms of self-replicating information because all of the historical data is still largely at hand and most of it occurred within living memory (see Programming Clay, SoftwareBiology and A Proposal For All Practicing Paleontologists).

In my last posting, SETS - The Search For Extraterrestrial Software I proposed that the chance of us falling prey to the malicious designs of alien software were rather slim because I did not think that there was much alien software, nor alien intelligence, out there to begin with. However, like most astrobiologists, I also have a high level of confidence that carbon-based life forms are quite common in our Universe. The fact that our Universe is just chock full of organic molecules that, thanks to the lobular quantized angular momentum of the electrons in carbon atoms, come in a nearly infinite number of huge molecules, with very complex geometries that can encode information, and consequently, form a framework upon which the self-replicating information necessary for life exists, would lead one to conclude that simple carbon-based life forms should be quite ubiquitous throughout our Universe (see SoftwareChemistry and Self-Replicating Information for details). This is further bolstered by the very early appearance of life on Earth a few hundred million years after the planet formed 4.5 billion years ago. Life on Earth most likely originated several thousand feet below the Earth’s surface in porous reservoirs near hydrothermal vents. The pore spaces in the heavily fractured rock near a hydrothermal vent would provide the ideal habitat, with an abundant supply of hot, energy-rich, organic molecules and crystal precipitating ions in the pore fluids circulating through the rock. This environment was also isolated from the planet-wide sterilizing impacts from the late heavy bombardment that peppered the Earth and Moon 4.1 – 3.8 billion years ago with countless impacts from comets careening in from the outer Solar System. It is thought that at the time of the late heavy bombardment, that Jupiter and Saturn had entered into a 2:1 orbital resonance, with Saturn making one orbit for every two orbits of Jupiter, and that the two planets had flung a nearby Neptune out to its current orbital position as the most distant planet from the Sun. Neptune then dislodged many of the surrounding comets from its new-found home, causing them to plunge in towards the inner planets like the Earth, producing many deadly collisions that boiled away the Earth’s oceans time and time again. Seeking refuge several thousand feet below the mayhem of the Earth’s surface allowed life to safely originate 4.0 – 4.2 billion years ago during the late heavy bombardment and persist in an undisturbed manner to this very day. In fact, there are still plenty of microbes down there. You can actually hire firms to analyze the bacteria in your oil field reservoirs to help prevent them from becoming soured by bacteria that produce hydrogen sulfide gas. In First Contact Kaufman also describes the work of Tullis Onstott and Gaetan Borgonie, who have found multicellular worm-like nematodes feeding upon bacteria at a depth of 12,000 feet in South African platinum mines. Onstott and Borgonie have shown that these little worms have followed their bacterial prey down from the surface and were not brought down by mining operations. In fact, William Whitman of the University of Georgia has estimated that half or more of the Earth’s entire biomass exists below 30 feet of the Earth’s surface, so we surface dwellers may be a bit of an anomaly. It is comforting to realize that even the blast from a nearby gamma ray burster could not completely sterilize the entire Earth.

So in the next few decades, as our observing telescopes and hardware get better and better, and eventually allow us to obtain spectra from distant planets orbiting neighboring star systems, we will most likely observe the signatures of primitive life forms in their atmospheres, like the simultaneous presence of both oxygen and methane, demonstrating an atmosphere far from thermodynamic equilibrium, and therefore, a home for living things. This will necessarily lead us to conclude that, at a minimum, simple single-celled carbon-based life forms must be quite common in our Universe. But once the thrill of making that determination has worn off, we will most likely still be left with a stony silence from our SETI radio telescopes, which by that time should have detected signals from alien intelligences, given the rapid pace with which SETI technology is currently progressing. Once we learn that simple prokaryotic carbon-based life forms are as common as rocks in our Universe, we will still be left with the nagging desire to find extraterrestrial intelligences. After all, that is really what our endeavors in astrobiology and SETI are really all about. In truth, we are lonely and want to find some companionship out there in the depths of space to help make it all seem worthwhile. Indeed, if we were to find ourselves to be totally alone in this Universe, it would certainly add to the apparent meaninglessness of it all in a very a nihilistic manner. But as I pointed out in SETS - The Search For Extraterrestrial Software, it may be very difficult for us to detect alien intelligences, especially if my scheme about self-replicating intelligent software broadcasting itself across an entire galaxy at the speed of light does not work in practice. After all, even Stephen Hawking has warned us about actively seeking out alien intelligences by broadcasting strong radio transmissions into interstellar space. Perhaps everybody out there is similarly wary, and all are just sitting back passively listening.

The first step in trying to find extraterrestrial intelligences hiding in deep space is to figure out what you are looking for. This is where the origin and evolution of software on Earth can be of help. In SoftwareBiology, A Proposal For All Practicing Paleontologists, and The Adaptationist View of Software Evolution, we saw that through a process of convergence, both carbon-based living things and software on Earth have followed the same evolutionary path through Daniel Dennett’s Design Space. Both began as simple unstructured entities that dominated for a very long period of time. Simple prokaryotic bacteria dominated the Earth for many billions of years before the arrival of structured eukaryotic single-celled organisms about 1500 million years ago that divided the functions of life up amongst a number of organelles, like the mitochondria and chloroplasts. These eukaryotic cells then came together to form simple worm-like multicellular organisms about 900 million years ago, and a few hundred million years later, the Cambrian Explosion, 541 million years ago, brought us the large multicellular organisms of today. Similarly, simple unstructured software dominated IT from 1941 – 1972, with an architecture very similar to the simple single-celled prokaryotic bacterial life forms of the early Earth. Unstructured software lost dominance with the arrival of structured software in 1972, which had an architecture very similar to the simple single-celled eukaryotic life forms, and divided processing up amongst a number of internal functions(), like the organelles of the eukaryotes. In 1992, object-oriented software came into dominance with the adoption of the object-oriented language C++ by the IT departments of many major corporations, and later, the arrival of Java in 1995, which clinched the object-oriented revolution in IT. Object-oriented software mimics the architecture of multicellular organisms because it consists of a large number of structured objects that send messages to each other, which subsequently induce exposed methods() to perform tasks within the objects, just as multicellular organisms consist of a large number of structured eukaryotic cells that send chemical messages called ligands to each other that bind to exposed membrane receptors on the surfaces of the cells, inducing them to execute public biochemical pathways within the cells. In 2004 SOA (Service Oriented Architecture) appeared on the IT scene, in which objects could make remote service calls upon service objects via, CORBA, RMI, or SOAP calls, like the cells within a complex multicellular body making service calls upon the organs within the body. Like the Cambrian Explosion, which brought forth several dozen phyla, or body plans, for the macroscopic multicellular life forms of the day, SOA has organized modern software into a number of Design Patterns like the Model-View-Controller (MVC) design pattern used by most web-applications today.

But this is not the end of the story for software. In SETS - The Search For Extraterrestrial Software, we saw that the three forms of self-replicating information currently on the planet - the genes, memes, and software - are currently in the process of morphing into a new hybrid form of intelligence, and this merging of self-replicating information into a new form of intelligence will probably be completed within the next 100 years or so. If that should happen, it might mean that carbon-based intelligences within our Universe might be quite fleeting things indeed. After all, the intelligent species Homo sapiens has only been around for 200,000 years, a mere blink of geological time. Carbon-based life forms begin as simple DNA survival machines that shield DNA from harm and support its replication processes, but as these DNA survival machines evolve more complicated neural networks, the neural networks begin to be parasitized by memes. Indeed Homo sapiens is not the only species on Earth currently loaded down with memes. Chimpanzees, bonobos, macaque monkeys, whales, dolphins, porpoises, and even songbirds are known to pass along cultural artifacts to the minds of others within their species, and these cultural artifacts, or memes, are observed to evolve over time, like the evolving songs of whales and songbirds. So by the time a carbon-based species attains enough technological memes to begin to search for interstellar radio transmissions or begins to broadcast on an interstellar basis itself, it will probably already be an amalgam of genes and memes, with software well on the way to becoming the dominant form of self-replicating information on their planet. Thus, most forms of intelligence within our galaxy will likely already be a hybrid of genes, memes, and software, or something even beyond. They will most likely not be simple carbon-based DNA survival machines like us, so we should stop exclusively looking for creatures of that sort.

So how do you find such creatures, especially if they are wary of revealing their positions by openly broadcasting radio transmissions into interstellar space? In First Contact Marc Kaufman describes the work of Richard Carrigan, a particle physicist at Fermilab, who has been using the existing data from infrared satellites to search for “Dyson spheres”. In 1960, Freeman Dyson published a paper entitled the Search for Artificial Stellar Sources of Infra-Red Radiation in the journal Science. In this paper, Dyson proposed that advanced civilizations would eventually attain a level of technology sufficient to completely surround their home star with a “Dyson sphere” composed of a loose collection of orbiting solar collectors that completely surrounded their star and converted its entire stellar output into energy useful to the civilization. The idea is that no matter how advanced a civilization may become, it will always be subject to the first and second laws of thermodynamics. Remember, because of the second law of thermodynamics, all forms of self-replicating information require a source of high-grade energy that can be converted into low-grade heat energy in order to replicate (see Entropy - the Bane of Programmers and The Demon of Software). For example, suppose we were to construct a Dyson sphere with a radius equal to the Earth’s orbit that completely absorbed the Sun’s entire energy output and converted this energy into electricity. Because the first law of thermodynamics requires that none of the Sun’s energy output be destroyed by the surrounding Dyson sphere, the Dyson sphere would necessarily have to emit an amount of energy equal to the amount of energy that it absorbed. However, it would do so by emitting photons with a much lower energy and spread over the much larger Dyson sphere. The radius of the Sun is 470,000 miles, while the radius of the Dyson sphere would be 93,000,000 miles. The Sun emits photons with a black body temperature spectrum of 5780 0K (9945 0F) that peaks in the visible range, while the much larger Dyson sphere would emit a much larger number of photons, but with a much lower black body temperature spectrum of only 300 0K (81 0F) in the infrared range. So to find Dyson spheres you have to look for strong infrared sources with black body emission curves in the range of 100 to 600 0K and associated wavelengths in the infrared range of 10 to 100 μm, and this is what Richard Carrigan has been doing by searching through the existing data from infrared satellites that were launched for other purposes. For more details on this fascinating SETI search, please see:


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Steve Johnston

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