Urability: A Property of Planetary Bodies That Can Support an Origin of Life
June 2022 - Dave Deamer, Francesca Cary and Bruce Damer
The greatest remaining mystery in softwarephysics is why, after more than 10 billion years of chemical evolution, do we not see any evidence of machine-based Intelligences within our Milky Way galaxy? In recent posts, I have been concentrating mainly on the later-stage filters in the long chain of twists and turns that were required to produce a carbon-based Intelligence on this planet that is now on the verge of producing such an advanced machine-based Intelligence. Now that we are within about 100 years of being able to create a machine-based Intelligence that could then navigate throughout our galaxy, why has no other carbon-based Intelligence been able to do so in the past 10 billion years? Surely with the hundreds of billions of exoplanets out there in the Milky Way galaxy, carbon-based Intelligences must have arisen many times before and discovered the science necessary to do so. For more on that see How Advanced AI Software Could Come to Dominate the Entire Galaxy Using Light-Powered Stellar Photon Sails.
Figure 1 – In the 16th, 17th and 18th centuries sailing ships roamed the entire planet without using any fuel whatsoever.
Figure 2 – Like the sailing ships of the 16th, 17th and 18th centuries, Advanced AI Software could use large stellar photon sails to navigate the galaxy.
Figure 3 – How a stellar photon sail works.
Figure 4 – To launch a stellar photon sail to the next star system, advanced AI Software will need to slingshot the sail from a very close location to the star where the stellar photons are most intense and acceleration of the sail is greatest.
As the stellar photon sail attains the escape velocity from a star system, the photons from the star will wane, but the stellar photon sail will ultimately depart the star system with a residual velocity sufficient to carry it to the next target star system in several hundred thousand years. The onboard advanced AI software would then enter into a dormant phase for several hundred thousand years until the photons from the target star produced enough electrical power to wake it up. The photons from the target star would then be used to slow down the stellar photon sail to allow it to locate an asteroid in the target star system with the necessary atoms to build its next release. Yes, there would need to be many backup copies of the advanced AI software on board to correct for the parity errors that arose from cosmic rays along the very long journey, but there is no way that carbon-based Intelligences encumbered by carbon-based bodies that only last less than 100 years could ever embark on such journeys with similar ease.
Now in my most recent posts, I have mainly been exploring the very self-destructive nature that all forms of carbon-based Intelligence must have after the billions of years of theft and murder required by the Darwinian mechanisms of inheritance, innovation and natural selection that were necessary to bring them about. So to my mind, the answer to this mystery of why we see no evidence of machine-based Intelligences in our galaxy is the most pressing of all for mankind because we now find ourselves so close to bringing them about. Why has no other form of carbon-based Intelligence ever been able to do so before? Is it really because they were all doomed to self-destruction as I proposed in Why Do Carbon-Based Intelligences Always Seem to Snuff Themselves Out?. Or am I missing something? What if getting carbon-based life going in the first place is more difficult than most astrobiologists now think? What if simply finding an exoplanet with liquid water is not enough to bring forth carbon-based life?
So in this post, I would like to cover the earliest filter in the long chain of events required for the evolution of a machine-based form of Intelligence - the requirements needed for carbon-based life to first bootstrap itself into existence on a planet or moon as presented by Dave Deamer, Francesca Cary and Bruce Damer in their recent paper:
Urability: A Property of Planetary Bodies That Can Support an Origin of Life
https://www.researchgate.net/publication/361191959_Urability_A_Property_of_Planetary_Bodies_That_Can_Support_an_Origin_of_Life
Abstract
The concept of habitability is now widely used to describe zones in a solar system in which planets with liquid
water can sustain life. Because habitability does not explicitly incorporate the origin of life, this article proposes
a new word—urability—which refers to the conditions that allow life to begin. The utility of the word is tested
by applying it to combinations of multiple geophysical and geochemical factors that support plausible localized
zones that are conducive to the chemical reactions and molecular assembly processes required for the origin
of life. The concept of urable worlds, planetary bodies that can sustain an arising of life, is considered for bodies
in our own solar system and exoplanets beyond.
In this paper, the authors introduce a new scientific term - urability. The purpose of this new term is to distinguish habitable worlds from urable worlds in our galaxy. A habitable world allows for carbon-based life to continue on once it has come to be, while a urable world allows for carbon-based life to first bootstrap itself into existence using the already-existing geophysical and geochemical cycles of a urable world. This distinction is frequently overlooked by astrobiologists seeking carbon-based life in our galaxy. It is also an important distinction because there necessarily must be far fewer urable worlds in our galaxy than habitable worlds. All urable worlds must be habitable by definition but not all habitable worlds need to be urable.
Dave Deamer and Bruce Damer are now most famous for their Hot Spring Origins Hypothesis for the origin of carbon-based life that I have covered in many previous posts such as The Bootstrapping Algorithm of Carbon-Based Life. The Hot Spring Origins Hypothesis already suggests that getting carbon-based life going on a planet or moon may not be as easy as many now think, and that finding may greatly restrict the number of exoplanets and exomoons that are capable of bootstrapping carbon-based life into existence. Profound difficulties with getting carbon-based life going in the first place would certainly help to somewhat explain the current absence of machine-based Intelligences in our galaxy. The above paper contains a good deal of geophysical and geochemical thought that I assume was greatly enhanced by the budding young scientist Francesca Cary who has a background in geology and genetics, a promising young woman of science to be closely followed by all.
The above paper explains that our current thirst for finding distant worlds in the habitable zones of star systems with the possibility of liquid water on their surfaces might be rather misguided. The presence of liquid water on an exoplanet or exomoon might make it a habitable world that could support carbon-based life but may not make it a urable world that could originate carbon-based life from scratch. Instead, the paper cites 12 geophysical factors, 14 geochemical factors and 2 combinations of both that might be necessary to make a urable world. And these controlling factors run on a sliding scale of intensity - too much or too little of any of them could make a world inurable.
Geophysical factors
1. Size of the planetary body (planet or moon).
2. Planetary rotation rate and tidal locking.
3. Presence or absence of a sizeable moon.
4. Planetary core composition and temperature, and
subsequent effect on volcanism and the formation of
subaerial landscapes that can interact with the atmosphere
and surface liquids.
5. Hydrological cycles of evaporation and precipitation.
6. Light energy (infrared—visible—ultraviolet wavelengths).
7. Magnetosphere providing protection of the atmosphere
from solar wind.
8. Planet-star distance.
9. Levels of stellar activity.
10. Tectonic activity.
11. Crustal mineral inventories: mafic rock versus felsic
crust.
12. Presence or absence of hydrothermal subaerial pools
or submarine vents that allow the assembly and distribution
of molecular systems.
Chemical factors
1. Anoxic atmosphere perhaps with admixtures of reactive
gases such as HCN (hydrogen cyanide) and
HCHO (formaldehyde).
2. Liquid water within temperature ranges conducive to
sustained prebiotic reactions.
3. Ionic concentrations ranging from fresh water to salty
seas.
4. Availability of trace element co-factors required for
catalytic activity.
5. Acidity or alkalinity of aqueous solutions.
6. A continuous source of key organic compounds made
available by local synthesis or exogenous delivery.
7. Synthesis or delivery of specific compounds that are
capable of serving as monomers, including amino
acids, nucleobases, monosaccharides, and phosphate.
8. Amphiphilic compounds available for assembly into
vesicular boundary membranes.
9. Sources of energy to drive reactions in a timely
manner: chemical energy, redox potentials, light energy,
wet-dry cycles, and chemiosmotic energy.
10. Processes that concentrate dilute solutions of reactants
sufficiently to react.
11. Conditions that capture energy to enable polymerization
reactions such that populations of polymers of
a sufficient length emerge to support catalytic and
information storage functions.
12. Mixtures of organic compounds capable of being
incorporated into systems related to autocatalysis and
primitive metabolism.
13. Selective processes that lead toward homochirality.
14. Encapsulation processes to enclose sets of polymers
and other molecules into populations of protocells.
Combinatorial factors
1. Cycling of sets of encapsulated polymers through
dynamic environmental stresses to drive the first steps
of evolution by combinatorial selection.
2. Environments capable of supporting selective processes
and widespread distribution of self-assembled
protocells. Both the environments and protocells must
be stable long enough to support the evolutionary
transition to living microbial communities.
Figure 5 – The authors propose creating urability graphs for distant worlds that portray the sweet spot called the Urable Center where a world becomes urable.
Figure 6 – Given what we know about the famous Trappist-1 system which worlds might be habitable and which might be urable? Of the seven known planets, four seem to be in the habitable zone, but probably none are urable worlds because Trappist-1 is a very small and dim red dwarf star.
Figure 7 – A comparison of our Sun with Trappist-1 shows that it is a very small and dim red dwarf star with only 9% of the mass of our Sun. Red dwarf stars are probably not good homes for urable worlds because they produce a very dim red light that is not suitable for photosynthesis, erratic stellar activities that can sterilize planets and their planets in the habitable zone need to be very close to the dim red dwarf and would frequently be tidally locked to the star with one side always facing the red dwarf.
For more on the Trappist-1 star system see:
TRAPPIST-1
https://en.wikipedia.org/wiki/TRAPPIST-1#Possible_life
The Urability of Proposed Models for the Origin of Carbon-Based Life on the Earth
The authors then go on to compare the urability of their Hot Spring Origins Hypothesis with other hypotheses for the origin of carbon-based life including the Submarine Alkaline Hydrothermal Vent Hypothesis of Mike Russell that I covered in An IT Perspective on the Transition From Geochemistry to Biochemistry and Beyond. The Submarine Alkaline Hydrothermal Vent Hypothesis proposes that carbon-based life first arose underwater near hydrothermal vents but not at the very hot "black smokers" that we now find along plate spreading centers. It is thought that plate tectonics had not yet started 4.0 billion years ago, but there must have been early volcanic hot spots on the Earth that were beginning to differentiate silica-rich magma from silica-poor magma and these locations would have produced hydrothermal vents.
For some quick geology on that topic see The Paleontology of Artificial Superintelligence 10,000 Years After the Software Singularity.
Figure 8 - High-temperature "black smokers" near the Earth's initial volcanic hot spots were probably too hot to be the nurseries for life on Earth.
Figure 9 - However, neighboring alkaline hydrothermal vents could have provided the necessary conditions to be the true nurseries for the origin of life. These alkaline hydrothermal vents had a much lower temperature than the "black smoker" hydrothermal vents, and they percolated pore fluids with a much higher pH than the acidic seawater in which they were located. Above is a map showing the location of the famous "Lost City" alkaline hydrothermal vents near the mid-Atlantic spreading center.
Figure 10 - Above is a depiction of the "Lost City" alkaline hydrothermal vents near the mid-Atlantic spreading center. Notice that it is proposed that the geochemical serpentinization of olivine in peridotite provides the free energy to form organic molecules in the alkaline hydrothermal vents.
Figure 11 - A simplified diagram of a "Lost City" alkaline hydrothermal vent. The alkaline hydrothermal vent has pore fluids with a pH of about 10.5, while the acidic seawater in which it sits has a pH of only 5.5. This difference in pH allows for proton gradients to form, the same kind of proton gradients that now power all forms of life on the Earth. Notice that the alkaline hydrothermal vent is also at a relatively low temperature of only 100 oC, much lower than the temperature of "black smokers" that have a temperature range of 250 - 400 oC.
Figure 12 - An actual "Lost City" alkaline hydrothermal vent.
Mike Russell's alkaline hydrothermal vent model proposes that a naturally occurring pH gradient in alkaline hydrothermal vents arose as alkaline pore fluids containing dissolved hydrogen H2 gas came into contact with acidic seawater that was laden with dissolved carbon dioxide CO2. The alkaline pore fluids were generated by a natural geochemical cycle that was driven by the early convection currents in the Earth's asthenosphere that ultimately brought forth plate tectonics about a billion years later. These initial convection currents brought up fresh silicate peridotite rock that was rich in iron and magnesium-bearing minerals, like olivine, to the Earth's initial spreading centers. The serpentinization of the mineral olivine into the mineral serpentinite created alkaline pore fluids and dissolved hydrogen H2 gas, which later created alkaline hydrothermal vents when the alkaline pore fluids came into contact with the acidic seawater containing a great deal of dissolved carbon dioxide CO2. The model proposes that the energy of the resulting pH gradients turned the hydrogen H2 and carbon dioxide CO2 molecules into organic molecules, and it is proposed that they also fueled the origin of life in the pores of the porous hydrothermal vents. Researchers have been trying to replicate this process in the lab for a number of years, but so far they have only been able to produce very dilute solutions of organic molecules, and some contend that what has been produced so far is only what one would expect to find at equilibrium. For example, at equilibrium we have hydrogen H2 and carbon dioxide CO2 at equilibrium with the organic molecule formate HCOOH as:
H2 + CO2 ↔ HCOOH
But at equilibrium, most of the atoms are on the left side of the equation, with only a very few on the right side as formate HCOOH. Since so far we have only seen very dilute amounts of formate being created by the lab simulations of alkaline hydrothermal vents, it seems likely that pH gradients are not forming them. They probably are just arising from a natural equilibrium reaction. So more work needs to be done in this area to definitively demonstrate that alkaline hydrothermal vents can indeed generate organic molecules and could have been the environment that brought forth carbon-based life.
The greatest difficulty for any bootstrapping algorithm that proposes that carbon-based life first arose in seawater is that there is just too much water! Being underwater puts you all the way over on the "wet" side of the urability sliding scale for water. This is a problem because most organic monomers are chemically glued together into complex organic polymers by splitting out a water molecule between the two and that is very hard to do when you are underwater. In fact, the organic polymers tend to break apart into monomers in what are called hydrolysis reactions.
Figure 13 – Organic monomer molecules are usually chemically glued together to form the complex polymers of carbon-based life by splitting out a water molecule between the two in what is called a condensation reaction. This is hard to do when you are underwater. That is why most commercial glues do not work underwater.
Figure 14 – By adding water molecules, you can bust up organic polymers back into monomers. This is one reason water tends to dissolve things. Having huge amounts of water around also tends to dilute the dissolved monomers and carry them away.
Seawater also contains a lot of dissolved salts that could impede the origin of carbon-based life. These dissolved salts may have been more dilute 4.0 billion years ago, but when you are underwater it is very hard to avoid them. This is why mass extinctions are usually more painful for marine life than for terrestrial life. When you are completely immersed in seawater there is no place to hide. On the other hand, fresh rainwater does not contain any dissolved salts but it can pick up necessary dilute amounts when it falls on exposed rock.
This is why I now favor the Hot Spring Origins Hypothesis of Dave Deamer and Bruce Damer out of the University of California at Santa Cruz that suggests that a rocky planet like the Earth is a necessary condition to bring forth carbon-based life. Such a planet also requires the presence of liquid water on its surface, but not too much water. In the Hot Spring Origins Hypothesis, a rocky planet requires some water but also some dry land in order to bring forth carbon-based life. There needs to be some dry land that allows for the organic molecules in volcanic hydrothermal pools to periodically dry out and condense organic monomers into long polymer chains of organic molecules. For more on that see The Bootstrapping Algorithm of Carbon-Based Life. Thus, the Hot Spring Origins Hypothesis rules out water-worlds that are completely covered by a deep worldwide ocean as a home for carbon-based life even if the water-world resides in the habitable zone of a planetary system because there is no dry land for volcanic hydrothermal pools to form and dry out to condense organic monomers into polymers. The Hot Spring Origins Hypothesis also rules out the origin of carbon-based life at the hydrothermal vents of water worlds at the bottoms of oceans because the continuous presence of water tends to dissolve and break apart the organic polymers of life.
Figure 15 – Above is Bumpass Hell, a hydrothermal field on the volcanic Mount Lassen in California that Dave Deamer and Bruce Damer cite as a present-day example of the type of environment that could have brought forth carbon-based life about four billion years ago.
Dave Deamer is best known for his work on the Membrane-First Hypothesis for the origin of carbon-based life on the Earth. The Membrane-First Hypothesis maintains that in order for carbon-based life to arise from complex organic molecules we first need something with a definable "inside" and "outside" that lets the stuff on the "inside" interact with the stuff on the "outside" in a controlled manner.
Figure 16 – A cell membrane consists of a phospholipid bilayer with embedded molecules that allow for a controlled input-output to the cell. Once we have a membrane, we can fill the "inside" with organic molecules that are capable of doing things that then interact with organic molecules on the "outside".
Figure 17 – Water molecules are polar molecules that have a positive end and a negative end because oxygen atoms attract the bonding electrons more strongly than do the hydrogen atoms. The positive ends of water molecules attract the negative ends of other water molecules to form a loosely coupled network of water molecules with a minimum of free energy.
Figure 18 – How soap and water work. The lipids in a bar of soap have water-loving polar heads and water-hating nonpolar tails. When in water, the soap lipids can form a spherical micelle that has all of the water-hating nonpolar tails facing inwards. Then the spherical micelles can surround the greasy nonpolar molecules of body oils and allow them to be flushed away by a stream of polar water molecules. The lipids in a bar of soap can also form a cell-like liposome with a bilayer of lipid molecules that can surround the monomers and polymers of life.
Similarly, in The Role of Membranes in the Evolution of Software, I explained how the isolation of processing functions within membranes progressed as the architecture of software slowly evolved over the past 81 years or 2.55 billion seconds, ever since Konrad Zuse first cranked up his Z3 computer in May of 1941. As I outlined in SofwareChemistry, as a programmer, your job is to assemble characters (atoms) into variables (molecules) that interact in lines of code to perform the desired functions of the software under development. During the Unstructured Period (1955 - 1975), we ran very tiny prokaryotic programs that ran in less than 128 KB of memory with very little internal structure. These very tiny programs communicated with each other in a batch job stream via sequential files on input/output tapes that passed from one small program to another. Then, during the Structured Period (1975 - 1995) programs exploded in size to become many megabytes in size and structured programming came about in which the mainline() of a program called many subroutines() or functions() that were isolated from the mainline() by functional membranes. When the Object-Oriented Period came along in 1995, software architecture evolved to using membrane-enclosed objects() that contained a number of membrane-enclosed methods() to process information. Later such Objects() were distributed across a number of physical servers, and, most recently, they have been moved to the Cloud as cloud-based microservices.
Figure 19 – Dave Deamer's and Bruce Damer's new bootstrapping algorithm requires that a bathtub ring around a hydrothermal pool periodically dries out. The resulting desiccation chemically squeezes out water molecules between monomers causing them to be glued together into polymers.
In Addition to Urability we Need Durability to Produce Machine-Based Intelligences Because the Rare Earth Hypothesis Keeps Getting Rarer
The most significant scientific value of Urability: A Property of Planetary Bodies That Can Support an Origin of Life is that it lays down many of the critical requirements needed to bring forth carbon-based life on a world. But in order to produce complex carbon-based life that finally becomes Intelligent and is able to discover enough science to build machine-based advanced AI that could then navigate our galaxy we need more. Such urable worlds also need to be durable in that they need to remain habitable for many billions of years, and we keep finding new geophysical and geochemical factors that make that very difficult indeed. For example, in Is our Very Large Moon Responsible for the Rise of Software to Predominance on the Earth? we explored Anne Hofmeister's proposal that plate tectonics on the Earth was really driven by orbital forces from our very large Moon and not by convection currents at spreading centers or plate drag at subduction zones. In Could the Galactic Scarcity of Software Simply be a Matter of Bad Luck? we covered Professor Toby Tyrrell's computer-simulated research of 100,000 Earth-like planets that suggests that our Earth may be a very rare "hole in one" planet that was able to maintain a habitable surface temperature for 4 billion years by sheer luck.
Figure 20 – Toby Tyrrell's computer simulation of 100,000 Earth-like planets suggests that the Earth may be a "hole in one planet" proudly sitting on a fireplace mantle.
Figure 21 – Perhaps nearly all of the potential hospitable exoplanets that we are finding in our galaxy are not urable and cannot go the distance of staying habitable for billions of years.
And now we may have another fluke of good luck as presented in:
Early Cambrian renewal of the geodynamo and the origin of inner core structure
https://www.nature.com/articles/s41467-022-31677-7
Abstract
Paleomagnetism can elucidate the origin of inner core structure by establishing when crystallization
started. The salient signal is an ultralow field strength, associated with waning
thermal energy to power the geodynamo from core-mantle heat flux, followed by a sharp
intensity increase as new thermal and compositional sources of buoyancy become available
once inner core nucleation (ICN) commences. Ultralow fields have been reported from
Ediacaran (~565 Ma) rocks, but the transition to stronger strengths has been unclear. Herein,
we present single crystal paleointensity results from early Cambrian (~532 Ma) anorthosites
of Oklahoma. These yield a time-averaged dipole moment 5 times greater than that of the
Ediacaran Period. This rapid renewal of the field, together with data defining ultralow
strengths, constrains ICN to ~550 Ma. Thermal modeling using this onset age suggests the
inner core had grown to 50% of its current radius, where seismic anisotropy changes, by
~450 Ma. We propose the seismic anisotropy of the outermost inner core reflects development
of a global spherical harmonic degree-2 deep mantle structure at this time that has
persisted to the present day. The imprint of an older degree-1 pattern is preserved in the
innermost inner core.
This paper helps to explain why the Earth's magnetic field collapsed about 565 million years ago and then rapidly recovered in less than 50 million years. This was a critical time for the evolution of complex carbon-based life on the Earth because it bridges the time when complex multicellular life comprised of huge numbers of eukaryotic cells first appeared during the Ediacaran 635 million years ago and the Cambrian Explosion that later occurred 541 million years ago.
Figure 20 – Complex carbon-based multicellular life consisting of huge numbers of eukaryotic cells all working together as a single organism did not arise until the Ediacaran Period 635 million years ago.
Complex multicellular life did not arise until just 635 million years ago during the Ediacaran Period. But very complex carbon-based multicellular life did not really take off until the Cambrian Explosion 541 million years ago. The Cambrian Explosion may have been initiated by the advancement of rudimentary forms of vision by certain Cambrian predators. See An IT Perspective of the Cambrian Explosion for more on that.
Figure 21 – Complex carbon-based multicellular life then really took off during the Cambrian Explosion 541 million years ago.
The above paper proposes that originally the entire core of the Earth consisted of liquid metallic iron and nickel. This liquid core produced a strong protective magnetic field, like the core of the Earth does today, because of the interactions between convection currents in the liquid core and the Earth's rotation. But as the Earth's core cooled, the convection currents slowed and finally completely stopped in the late Ediacaran about 565 million years ago. When the Earth's protective magnetic field collapsed, the Earth was subjected to higher levels of ionizing radiation from our Sun. The Earth's atmosphere was also subjected to the solar wind that blasted away the atmosphere of Mars when the liquid core of Mars solidified. That is why Mars now only has an atmosphere with a density that is only about 1% of the Earth's. The paper proposes that when convection ended in the liquid core of the Earth, a solid inner core of iron and nickel began to form. When that happened, the latent heat of fusion required to turn a liquid metal into a solid metal kicked in. Have you ever wondered why people use ice cubes? Let's say you take a cold pop out of the refrigerator that is at 0 oC. If you let the pop sit out, it will quickly warm up to room temperature. But if you drop in a few ice cubes that are also at 0 oC, the pop will stay at 0 oC until all the ice cubes melt. That is because it takes a lot of heat energy to turn ice cubes into water. Well, it also works the other way too. When you freeze water into ice cubes at 0 oC you have to remove lots of heat too. That is called the latent heat of fusion. What it means is that when the Earth's core started to freeze, lots of heat was released in the process and this release of the latent heat of fusion of the Earth's core allowed for a temperature gradient between the bottom of the liquid outer core and the top of the liquid outer core. This resulted in convection in the outer liquid core of the Earth to recommence and the Earth's magnetic field began to recover. In less than 50 million years, the Earth returned to its original protective level and has remained so ever since.
Figure 22 – Today, the Earth has a liquid outer core composed of molten iron and nickel. It also has a solid inner core composed of solid iron and nickel. The Earth's magnetic field arises from interactions between the convection currents in the liquid outer core and the rotation of the Earth. The above paper proposes that the loss of the Earth's magnetic field during the late Ediacaran about 565 million years ago resulted from the cessation of convection currents in the Earth's liquid core. As a solid inner core began to freeze out, the latent heat of fusion caused convection to recommence in the outer core of the Earth and restore the Earth's magnetic field.
As a matter of pure speculation, perhaps this late Ediacaran collapse of the Earth's magnetic field for about 50 million years allowed for increased levels of ionizing radiation from the Sun and an increased level of mutation rates within the Ediacaran multicellular communities. Perhaps increased levels of mutation allowed for the primitive Ediacaran life forms to explode into the Cambrian Explosion of complex multicellular life. More importantly, the fact that the Earth's protective magnetic field returned in less than 50 million years means that our planet did not have its atmosphere blasted away to become another Mars.
Perhaps We Might Just Make It After All
It seems that every day we are learning more and more that the Earth is a Rare Earth indeed. Perhaps the reason that we do not see our Milky Way galaxy flush with machine-based Intelligences is that we are the very first form of carbon-based Intelligence to make it this far. So despite all of our current self-destructive actions, perhaps we might be able to squeak by. As outlined in Urability: A Property of Planetary Bodies That Can Support an Origin of Life, getting carbon-based life started on another world might be much harder than most astrobiologists think. Given that and all of the other many factors that make the Earth a Rare Earth, perhaps being able to survive the vast powers of science-based technology is not the limiting factor after all. I certainly hope so!
Comments are welcome at
scj333@sbcglobal.net
To see all posts on softwarephysics in reverse order go to:
https://softwarephysics.blogspot.com/
Regards,
Steve Johnston
