29. Prospects of Nonhuman Intelligences

Transcript: In terms of life beyond Earth and life beyond the solar system, what are the prospects? Astronomers have learned that long-lived stars, planets, and carbon chemistry seem to be universal phenomenon. We know that planets exist around many nearby stars. We know that carbon is readily produced by many stars throughout the Milky Way galaxy and in all the hundred billion galaxies beyond the Milky Way. In drawing conclusions from the history of life on Earth, scientists may surmise that primitive life or microbial life forms may be common in the universe whereas complex life and intelligence may be rare. However, the possible modes of life are essentially unknown. Although the traditional debate is framed in terms of biochemistry, if the minimum requirement for life is only thermal disequilibrium and information storage, then there are other possible modes for life that we have not yet discovered. Either way, the next few decades will probably show us the answer to the question, “Is there life in the universe?” and the new knowledge we gain will change us forever.

Transcript: In terms of our speculation about life in the universe, what can we conclude with all the information we have learned about the history of life on Earth. We have learned that life formed very early in extreme conditions. We’ve learned that carbon chemistry offers many different pathways for life processes. We’ve learned that the energy sources and chemical natures of life can be varied even though the biological basis of all organisms has a single common ancestor. We’ve learned that life radiated into many environments and that extremophiles have taken up conditions that match the extreme conditions on some of the planets in the solar system. We’ve learned that intelligence has been rare and slow to develop on Earth and that intelligence and technology are a rare outcome of natural selection.

Transcript: The Multiverse concept seeks to explain the unusual conditions in our universe by hypothesizing a multitude of universes with different physical properties. In only a tiny fraction of those universes are the physical conditions or the laws of nature suitable to the formation of stars and carbon and life, but is this falling into a logical trap? It’s called the inverse gambler’s fallacy. It says that rare or improbable events are more likely to occur somewhere or other in a long trial of runs than in a short one. Imagine you role a pair of dice many times. You are clearly more likely to throw a double six at some point than if you had only rolled them once, but this does not mean that after a long run of throws without a double six the next throw is any more likely to be a double six. In terms of this gambler’s analogy, it would be false to infer a long run of throws from the fact that someone has just thrown a double six. It’s always a one in thirty six shot, so the supposition does not explain it. Equally, the idea that there have been randomly many universes either in series or in parallel does not make this particular universe any less improbable, and so it does not explain it.

Transcript: Scientists tend to think in traditional and anthropocentric ways about the possibilities of life in the universe. The Drake equation is a deductive framework, the multiplication sequentially of several probabilities. It works in terms of the possibility of Sun-like stars and Earth-like planets around those stars, under a premise of carbon chemistry, and a strong assumption that intelligence and technology are related to communication through space, but we should think inductively about life in the universe. We may not have the answers to the questions raised in an inductive framework, but they are probably more revealing about the possibilities of life elsewhere in the universe. In terms of sites for life, we should consider the full range of sites, illuminated by extremophiles on Earth, the possibility of life around stars that are quite different from the Sun, or perhaps even in gaseous environments in the universe. In terms of the nature of life, we should consider the possibility of non-carbon based biochemical life and even of artificial life, of the fact that intelligence might exist without technology, and of the heavy role of contingency in evolution and natural selection. In terms of communication, we should consider the possibility of non-electromagnetic communication and the role that culture plays in the attempt at communication. And finally, we should consider what might happen with large advances in life and a long span in the possibility of interstellar networks and robots.

Transcript: Chaotic inflation and the concept of the multiverse are an extraordinary potential insight into our role in the universe. These theories say that at the time of quantum genesis, only one space time seed inflated to become the large and old universe that we live in. Many other possible space time fluctuations could have lead to other universes with physical properties utterly different from ours. However, in the huge range of possible physical properties or laws of nature, only very specific and narrow ranges accommodate the existence of carbon and chemistry and biology and life. So we live in one of the very small fraction of those huge number of potential universes in which life could exist. This is an attempt to explain the anthropic principle in terms of a huge number of universes. It violates the historical idea and the scientific method of Occam’s razor, but the simplest explanation is best. We’ve hypothesized a huge number of universes that are in principle unobservable because they are outside our space-time continuum and use it as an explanation for the particular properties of our universe. It has some attractions, but it’s not clear this is standard science because how could we test such an idea.

Transcript: The anthropic principle can be connected to modern cosmological theories in a fascinating way. In current big bang theories, the universe had a quantum genesis. It emerged from a tiny seed of space-time, much smaller than the nucleus of an atom. This was called the Planck era, when the four forces of nature melted together. The birth of the universe was a quantum fluctuation event that led to a rapid expansion and inflation to the universe as large and old as we see now. Hypothetically, out of this original quantum state other universes could have been created and then maybe even destroyed. Some universes may have been long lived like ours and filled with matter and radiation. Others may have been temporary and evanescent. Some may have had radiation but no matter. Others may have had equal amounts of matter and antimatter. Others could have had the forces of nature different. Still others could have had such a value of entropy as to lead to no arrow of time. This panoply of possible universes is called the multiverse, and in this version of hypothetical quantum creation, only a small fraction of these universes would have had the properties suitable for life to evolve. In this sense, we do live in the best of all possible worlds.

Transcript: The cosmological anthropic principle connects the existence of life in the universe to the global geometry of the universe. The universe we live in has a spatial geometry very close to flat, and has a matter density within a factor of three of the critical density at which the cosmic expansion is slowly decelerated over cosmic time. The universe could have any value of the mass density. For hypothetical universes with much larger values of the matter density, these universes would have closed and re-collapsed a long time ago. In most of these hypothetical universes, there would not have been time for stars to form, evolve, and create carbon; they would have re-collapsed after millions of years. So, these would have been universes without biological life. In another set of hypothetical universes with much lower values of the mass density than the universe we live in, the early expansion would have been so rapid that stars and galaxies could not have formed out of the rapidly expanding material. Once again, with no stars, no carbon could have been created, and so no biological life would have been possible. Thus, out of the vast range of possible and physically plausible universes, only those with matter density in a particular narrow life could have biological life as we understand it. This is a fine-tuning argument on a cosmological scale.

Transcript: The anthropic principle has been and can be criticized on purely logical grounds. Obviously one of the grounds is the fact that it doesn’t necessarily make predictions. It just seeks to retroactively explain why the universe has properties that would allow life to exist. It’s subject to a more fundamental fallacy as well called the observer’s fallacy. The first point, people should not be surprised that they do not observe features of the universe which are incompatible with their own existence, and the second point that people should not be surprised that they do observe features of the universe which are compatible with their own existence. The first statement is obviously true, but logically the second does not follow from it.

Transcript: The weak form of the anthropic principle in essence states that we can only live in a universe that has the properties such that we can exist. In other words, we can only exist in the universe and should not be surprised that the universe has the properties to allow long-lived stars to exist and carbon to have been created. This sounds like a truism or a tautology, but the anthropic principle elevates it to a level of a scientific theory with hopefully predictive powers. It may not have predictive powers due to the prospect of observational selection. Consider an example of a fish story. You catch a fish that is 23.2576 inches long, exactly that long, in a lake. Then, afterwards, you test your apparatus and discover that it could only have caught a fish this length to within one part in a million. This is the analog of the fine tuning that the universe exhibits in its fundamental properties. From this information do you conclude a) that the lake has many fish of different lengths and you eventually found the one that you could catch, or b) that there is only one fish created by a deity who wanted you to catch it? These are the two possible ways you can look at the anthropic principle.

Transcript: The strong version of the anthropic principle in essence states that the observed values of physical and cosmological quantities are not accidents but are connected somehow with our existence as observers of the universe. The universe was built for us. This sounds like an extraordinary statement, yet at the level of microscopic physics there is a clear tradition in quantum mechanics of a relationship between the observer and the thing being observed. Our best microscopic theories of nature state that it is impossible to observe physical systems without disturbing them. In other words, the observer and the universe are entwined and intimately connected at the level of microscopic physics. How this might play out on larger scales is utterly unclear, but it is not true that the universe in every essence exists independent of our observation.

Transcript: When astronomers and physicists are trying to explain coincidences in nature with the anthropic principle they must be aware of a fundamental argument in the field of philosophy. It’s called the argument from design, and it was best put in this quote by Bertrand Russell. “You all know the argument from design. Everything in the world is made just so that we can manage to live in the world, and if the world were ever so little different, we could not manage to live in it. This is the argument from design.” Bertrand Russell’s comment is that there is no logical proof of any hypothesis such as the anthropic principle just by arguing that the world had to be the way it is so that we could exist in it. In complex situations in nature, there’s often a strong connection between function, design, and form. For example, why are mountains the size they are on the Earth? Simply, if they were any bigger, the pressure at the base of the mountain would melt the rock, so there is a natural limit. Why are animals the size they are on Earth and no bigger? Because if they were any bigger, they would break. Size of an animal increases roughly as the cube of the dimension, but the bone strength only increases as a cross sectional area, or the square of the dimension. So an animal that gets too big will in fact break. Thus there are often physical reasons why things are the way they are in the natural world, but we must uncover them.

Transcript: Miss Marbles, Agatha Christie’s fictional detective hero once said, “A coincidence is always worth noticing. You can always discard it later if it proves to be only a coincidence.” What are we to make of the coincidences that exist in nature, by which we mean not any coincidence but coincidences of physical constants or fundamental properties of matter that seem to be conducive to the creation of chemistry, biology, and life itself? It’s hard to know what to do with this information. Perhaps the first anthropic argument was provided by Sir Fred Hoyle, a famous cosmologist, when over fifty years ago he realized that the particular level of an energy transition in the carbon atom facilitated the creation of carbon in massive stars. If this energy level were slightly different, by less than a percent, carbon could not be created in the standard cycle in massive stars. Carbon could not exist, and so biology could not exist as we understand it. Is this a coincidence? How are we supposed to interpret this very specific property of nature that makes the universe conducive to life?

Transcript: The existence of life in the universe also depends fairly sensitively on the ratios of certain fundamental particle masses. If the ratio of the proton to the neutron mass was not approximately one, in the early big bang the fusion processes would have created almost all neutrons or all almost protons, with the result being that there could have been no stable nucleides and no chemistry, and therefore no biology. If the proton to electron ratio were not roughly as large as it is, almost a factor of 2,000, once again the physics of the universe would have been such as to allow no chemistry or no solid matter. Gravity could be different and life could arise in a scaled-up or a scaled-down universe, but the general principle is that many of the fundamental ratios of particle masses in nature, and the strengths of the fundamental forces could, in principle, take a variety of values. Such universes would have different physics from our universe, but it would be plausible physics, realistic physics, and reasonable physics. The only difference would be that chemistry, biology, and life would not be possible.

Transcript: The existence of life in the universe is also very sensitive to the electromagnetic force and its absolute strength. If the electromagnetic force were slightly stronger than it is now, stellar luminosities would be sharply lower then they are in the present day universe. Stars would be too cold to have any kind of extensive habitable zones, and no elements beyond iron would have been created in the history of the universe. If the electromagnetic force were much weaker than it is now, all stars would be very hot and have very short lives. With stellar lifetimes typically a million years or less for stars of any mass, as compared to billions of years or more for current day stars of low mass, there wouldn’t have been long enough for complex biological life to have developed even if there had been habitable planets. Thus, the existence of life on Earth and life elsewhere in the universe is fairly finely tuned to one of the strengths of a fundamental force of nature.

Transcript: As examples of fine tuning in nature, consider the strength of the nuclear forces that hold the atom and the nucleus together. If the weak nuclear force were much stronger than it is, the big bang would have cooked all the hydrogen into helium rather than just a fraction of it with the result that in the present day universe there could be no water and no long-lived stable stars. If the weak nuclear force had been much weaker, early neutrons would not decay into protons and there would be no hydrogen at all. The strong nuclear force that binds the atom’s nucleus, if it were only two percent stronger, no protons would have formed early in the universe. Diprotons would have formed instead. There would therefore have been no stable atoms, and stars with diprotons in them would have burned a billion times faster than stars in our universe. If the strong nuclear force had been five percent weaker, the deuteron would not be bound, and stellar fusion would have been impossible. What all this means is that if either of the nuclear forces had been slightly different, the universe would have been physically reasonable but not a place where long-lived stars, biology, or life would have been possible.

Transcript: Nature exhibits certain coincidences that physical scientists have to take note of. Even if the physical laws of nature are described by an as yet unknown fundamental physical theory, we have to be able to understand why the forces of nature are the way they are, why they masses of fundamental particles are the way they are. Normally, this would not be a cause for interest when considering life in the universe, but it turns out that many of the physical properties of the universe we live in are finely tuned and in such a way as to be propitious for the existence of biological life. Is this a coincidence, or was this built into nature somehow? The second possibility is called the argument from design. It’s actually been criticized by philosophers as famous as Bertrand Russell, but still we are left with the fact of we have to explain the properties of our universe and the fact that they happen to be propitious for life.

Transcript: The anthropic principle is an extraordinary idea that is somewhat controversial even amongst scientists. It’s possible that the existence of life in the universe is not an accident, that the role of life in the universe is more central than we might imagine. The anthropic principle postulates that the presence of life in the universe is intimately connected with the properties and structure of the universe itself. There are several forms of the principle. The weak form of the principle is almost a tautology, saying only that we must observe properties of the universe that are consistent with the presence of life. The strong form is far more dramatic, saying essentially that the universe is built for life and must have had life because it contains us. Notice that this idea, the anthropic principle, completely subversed the Copernican principle of mediocrity where there is nothing special about us, our star, our planet, our galaxy, or our biology. It says that we are central to creation and existence. The primary criticism against the anthropic principle is that it’s not predictive in a standard scientific way, but it’s provocative enough to have stirred up debate amongst philosophers, scientists, and even theologians.

Transcript: Why do people so strongly believe in aliens despite no evidence for their existence? When Orson Wells’ radio War of the Worlds episode was broadcast, it caused widespread panic on the east coast because people were ready to believe that Martians could attack us. When Star Wars and Star Trek and the X-Files moved from the status of simple movies or TV shows to widespread cultural phenomena, it’s because the idea of aliens resonates with something deep in our psyche. The idea of aliens, intelligent aliens, embodies our deepest hopes, fears, and longings. In the pessimistic view, such as movies like Alien and Independence Day, they could destroy us. In the optimistic view, represented by the movie Contact, they could inform and rescue us. Many movies and TV shows illustrate a strict biblical or religious metaphor. The best example is Spielberg’s movie E.T. where E.T. follows a direct analog of the Christ story. This thing, this phenomenon of the aliens embodying our hopes and fears and longings raises a different question than, are we alone? Perhaps the real question is why are we so lonely?

Transcript: It may or may not be reassuring to know that SETI researchers have protocols in place for what to do if we finally detect evidence of intelligent aliens in space. Protocols have been set up to contact the United Nations and the world leaders and to avoid the widespread panic that might ensue. The truth is, we have no idea of the likelihood of SETI experiments being successful. We are compelled to do such experiments, and almost all that we know is that the idea and the reality of finding intelligence elsewhere will change us forever. Since our lifetime of a civilization and of the human species is so much less than the age of the Milky Way, it’s most likely that anyone we contact is likely to be far more advanced than us which is a sobering thought. The discovery of life or intelligence in the universe would be the final step in the Copernican Revolution with dramatic impacts on human culture and religion.

Transcript: While scientists conduct, on a modest scale, the search for extraterrestrial intelligence, a significant number of people think we already know the answer. The majority of the American public believes that UFOs exist, that contact has already been made with aliens, that perhaps the government is hiding such information from us. Also, many people believe that there are biblical references to aliens or that alien visitations are encoded in many ancient human cultural artifacts like the pyramids or lines drawn on the plains of Mexico. The evidence for alien visitation is slim to none. Scientists raised a very high bar for deciding whether aliens have visited. As Carl Sagan said, extraordinary claims require extraordinary evidence. That evidence is not present in the case of UFOs and alien visitations. Virtually every scientist believes that there is no good evidence of alien visitations. It’s also clear there’s anthropocentric thinking involved. Ancient UFO sightings of course used to look like galleons in space in a time before there were spacecrafts. UFOs only started to look like rocket engines and spacecraft when we had that technology ourselves. If people want to believe, they will believe, but the scientific evidence does not favor any previous contact.

Transcript: The issue of what message to send if we want to communicate with extraterrestrial intelligences is a very interesting one. If the message is too simple, it may be understood but will convey little information. If it’s too complex, it can carry more information, but it’s unlikely to be able to be decoded. So we must avoid anthropocentric thinking. Most of the previous experiments, the Pioneer plaque, the Voyager record, even the Arecibo message, are highly anthropocentric involving the visual sense or anthropocentric views of human artifacts and culture. Other people have looked at a more universal language. Hans Freudenthal developed what he called Lincos or the lingua cosmica, a language that could be digitized based entirely on logic. Other people have speculated that sending complex mathematics ideas in space would be the best way to show that we understood how the universe works. Roger Penrose has extended these ideas to the idea of digitizing and sending into space a universal touring machine which is a binary coded message that shows we know how to construct universal computing engines.

Transcript: As a follow up to the Pioneer Plaque, the Voyager 1 and 2 spacecraft, which have also left the solar system, carried a phonograph record, a twelve-inch gold disc containing samples of the world’s music, spoken greetings in many of the world’s languages, and images of various kinds digitized and placed on the record. The arbitrary selection of musical choices was of course the selection of a small set of people. Some people might argue. For instance, the record was made before rap even existed. So, it’s an arbitrary cultural selection to decide which part of human endeavors to represent. Maybe more fundamentally, it’s an illustration of the transience of technology. The record that was attached to the leg of the voyager spacecraft is of course an old style LP, a technology that is obsolete even on Earth, so we must view both the Pioneer and the Voyager experiments not as realistic attempts to communicate with aliens but as representations of our own culture, maybe to make us feel better about ourselves.

Transcript: The first message to leave the solar system from humans towards aliens was attached to the leg of the Pioneer 10 spacecraft. It was a plaque designed, amongst others, by Carl Sagan and Frank Drake. This gold plaque contained graphics indicating aspects of human culture and indicating their intelligence. There were two naked human silhouettes, a map of the solar system showing the path of the Pioneer spacecraft, a schematic of the hydrogen molecule, a silhouette of the spacecraft itself, and most importantly a pulsar map showing aliens how to triangulate the distance of the Earth in terms of eighteen different pulsars whose frequencies were marked out in binary tick marks along the line of each pulsar. It’s again highly debatable whether anyone could understand or make sense of such a map. We would have to assume the visual sense and that they could understand or interpret the graphics that were represented on the plaque. Realistically, the Pioneer plaque should not be seen as an attempt to communicate but more as a message in a bottle thrown out into the depths of interstellar space to tell someone potentially far in the future that we exist, that we had a technology, and we were intelligent.

Transcript: Rather than simply theorize or speculate, astronomers have been conducting modest experiments in interstellar communication. One of the first and most famous was done in 1974 using the Arecibo Radio Telescope, a thousand-foot radio dish in Puerto Rico. A pulsed set of messages was sent out sequentially to the M13 globular cluster. The sequence of signals consisted of one thousand six hundred and seventy-nine bits of information, that is on-off radio pulses. An intelligent civilization receiving such a message would presumably realize that sixteen seventy-nine has only two factors, seventy-three and twenty-three, suggesting hopefully two ways to arrange the information in a grid. One way produces a meaningless picture but the other way clearly indicates graphics if you also understand that you are to turn the bright or on signals into dark and the light into off, thus converting on-off signals into light and dark, or a picture. When shown this way, the Arecibo signal consists of a graphic of the solar system, of the Arecibo Radio Telescope, a little stick man, a schematic of the DNA molecule, and eight of the primary amino acids involved in life, but it’s just a schematic. There is no language involved and a civilization would have to understand what it means. It’s all very hypothetical anyway because M13 is twenty-five thousand lightyears away, so we will have to wait nearly fifty thousand years for a response if any is coming.

Transcript: If we want to communicate through interstellar space with intelligent civilizations, we’ll have to decide on what message we want to send and how to code it. This is highly complex. How do we turn a subtle and complicated idea into a simple set of signals or bits of information? We have to reduce complexity to simple form, ones and zeroes, on and off, light and dark. This is a difficult process. We presume that a successful SETI signal will have to be pulsed to distinguish it from cosmic noise or other astrophysical sources of radiation. We presume that a successful signal that carries meaning will have to have a pattern. In other words it is neither random, nor completely regular. A completely regular periodic signal carries only one bit of information, the frequency of the pulsed source. These are the principles, but in practice it is likely to be far easier to decide that any signal that we might receive is nonrandom than to actually decode what it means. This is one of the fundamental lessons of cryptology.

Transcript: Even if we accept the premise of SETI, that intelligent civilizations exist, and we accept the methodology of using radio waves to communicate across large distances of space and time, we are still left with a profound question. What should we say, and how should we say it? The idea of communication involves the idea of a message, but how do we encapsulate human intelligence and civilization in a message that can be coded and transmitted across regions of space? The danger, obviously, is anthropocentric thinking, couching our message too much in terms of human specific intelligence and culture. The specificity of culture and language should not be exaggerated. Remember that we share the planet with great apes like gorillas with whom we share ninety-nine percent of our DNA, yet we cannot communicate with them. We also have orcas and dolphins which may be intelligent, but we can communicate with them. So imagine now how difficult it might be to communicate with aliens of utterly different function and form.

Transcript: Although traditional SETI is conducted in terms of radio waves and their communication, it’s worth considering the possibility of optical SETI, using light waves to communicate through interstellar space. This has become possible due to current and modern technologies. For example, we have lasers which in a pulsed mode can outshine the Sun by a factor of ten thousand, if only for a microsecond or less. If such lasers existed on planets around nearby stars and were being pulsed in a meaningful way, these pulses would outshine the stars, and so the pulses would be visible from a very large distance. So in principle, optical intelligent signals could be seen. An even more sophisticated technique would involve a civilization aligning its signals with an intervening star or planet and using gravitational lensing to magnify, focus, and amplify the starlight, thus boosting the signal across large regions of space.

Transcript: Why has the SETI strategy focused so heavily on radio waves for communication? There are simple reasons to do with fundamental physics. Radio photons are preferred over optical photons because they have low energy and so are less costly to produce in energetic terms, and they travel unimpeded through space, being unaffected by dust and gas. Also, there are regions of the electromagnetic spectrum where there are minimum amount of cosmic noise from other energy sources, and the radio part of the spectrum from one to a hundred gigahertz is just such a range. Also the sensitivity of our technology to radio detection is extraordinary. The Pioneer 10 satellite, currently at a distance of more than six billion miles from the Earth was detected by the Arecibo Radio Telescope when it was five billion miles from the Earth, yet it had the equivalent energy in its transmitter of a one Watt radio light bulb. The Arecibo dish itself, a thousand feet across, is the world’s largest radio telescope. In an interesting thought experiment, the Arecibo radio dish can not only listen but can send pulsed microwaves. If Arecibo-type radio technology existed anywhere else in the Milky Way galaxy, we could detect it if it were transmitting pulsed signals. Presumably the converse is true, and they could detect us. Thus radio waves, in principle, allow communication across the entire Milky Way galaxy.

Transcript: Why has the SETI strategy focused so heavily on radio waves for communication? There are simple reasons to do with fundamental physics. Radio photons are preferred over optical photons because they have low energy and so are less costly to produce in energetic terms, and they travel unimpeded through space, being unaffected by dust and gas. Also, there are regions of the electromagnetic spectrum where there are minimum amount of cosmic noise from other energy sources, and the radio part of the spectrum from one to a hundred gigahertz is just such a range. Also the sensitivity of our technology to radio detection is extraordinary. The Pioneer 10 satellite, currently at a distance of more than six billion miles from the Earth was detected by the Arecibo Radio Telescope when it was five billion miles from the Earth, yet it had the equivalent energy in its transmitter of a one Watt radio light bulb. The Arecibo dish itself, a thousand feet across, is the world’s largest radio telescope. In an interesting thought experiment, the Arecibo radio dish can not only listen but can send pulsed microwaves. If Arecibo-type radio technology existed anywhere else in the Milky Way galaxy, we could detect it if it were transmitting pulsed signals. Presumably the converse is true, and they could detect us. Thus radio waves, in principle, allow communication across the entire Milky Way galaxy.