The simple question asked by the physicist Enrico Fermi concerning the search for extraterrestrial intelligence (SETI) which has come to be known as the Fermi Paradox. It is: “Where are they?”

It's not as stupid a question as it seems since there is no evidence that our galaxy, which contains over a hundred billion stars, has been altered in any manner that can be attributed to intelligence in all the billions of years of its existence. Nor is there any convincing evidence of extraterrestrial visitation of Earth either in prehistory or now, despite what some people may claim. As we have seen, the idea that UFOs are spaceships from another star system is probably the least plausible explanation of the phenomena. If intelligent life is common throughout the galaxy why has not the Earth been exposed to waves of colonization? In less than a century we will have the capability to begin our colonization of the galaxy using self-replicating starships. Even at a relatively low rate of expansion we should have a presence throughout the galaxy in less than ten million years, and probably quite a bit sooner given a mature starship technology. Now, ten million years might seem a long time but it is less than a tenth of one percent of the age of the galaxy. Even the dinosaurs lasted more than ten times longer than this.


The Fermi Paradox is essentially the question that if we can do this why has nobody else given that the conditions for life have been suitable elsewhere for billions of years even before the Earth formed? Why isn't our solar system strewn with artifacts and mining operations from dozens, or even hundreds, of waves of such colonization across billions of years?



Where are they?


This question has become even more pointed in the past couple of decades with the rise of Transhumanism and the realization that our previous science fiction type scenarios grossly underestimate the damage an expanding civilization would do to the apparent existing cosmic environment. Indeed, a good case can, and has, been made for the logic of expansion to be one of effectively strip mining the entire universe and turning it into Computronium – lifeless matter into mind. One can imagine such a civilization arising several billion years ago and doing just that. By now, everything should be gone, but obviously it is all still here. When we look at the night sky we see a pristine environment – no radio noise from other civilizations, no anomalous radiations of any kind, no Dyson Spheres or their associated infra-red signatures, no Matrioshka Brains and a local solar system that appears untouched. A paradox.


There are of course quite a few possibilities that have been discussed and the major ones are listed below. They generally fall into a few categories:

• We are the first intelligent technological race in the galaxy, or even universe. Given that there are approximately as many stars in the universe [3] as grains of sand on every beach in the world this seems unlikely.

• All technological races, without exception, destroy themselves before they reach the starship building stage

• Everyone, without exception and across billions of years, stays home for some unknown reason or becomes ecologically enlightened on a cosmic scale and never indulges in cosmic engineering

• The Zoo Hypothesis – that our solar system has been shielded from these colonization waves for hundreds of millions of years, and still is. Additionally, that this involves presenting a false view of the universe we see around us.

• The universe is not what we assume it to be – we are missing something important

The problem is that apart from the last option all the others seem extremely improbable. Naturally, one might view that last option as being self-evident as far as a modern scientific understanding of the universe is concerned. The question then becomes one as to whether there are any clues as to what is going on. Which brings us to a series of peculiar statistical arguments concerning reality and our place in it here and now. The first is called the Doomsday Argument and it indicates that almost certainly we are nearing the end of Human existence. Of course, given the previous chapter on The Great Work and Transhumanism this will probably not come as much of a shock as it might, unless you are reading the book out of sequence!

The Doomsday Argument [2]


Suppose someone presented you with a bag of marbles and claimed that they contained a million blacks and one white, and then asked you to put your hand in and pick one of them. Which, of course, you do and amazingly you discover that it is white. Now this is an incredible piece of luck akin to winning the national lottery – in fact, a million to one probability. Then the person tells you that they have lied about the number of black marbles in the bag, although they do not actually tell you what the real number might be. So, you start thinking... how many black marbles are likely to be in the bag – what's a plausible number? One hundred perhaps? But picking a white marble from that would still be a one in a hundred chance. So perhaps ten might be more plausible, or even less.


Anyway, let's cut to a completely different scenario drawn from a science fiction view of the future of Humanity made popular in series like Star Trek, movies like Star Wars or any number of books over the past century. This is the one where we go on to populate the galaxy, and indeed universe, across millions of worlds and with trillions of trillions of Humans living and dying across millions of years. Now suppose we take a rather New Age view of a soul floating around in hyperspace or wherever souls waiting to incarnate reside, looking to randomly incarnate in a Human body located somewhere in space and time. So, it does this and discovers that it is now living on Earth in the early 21st Century.



Amazing! Out of all those planets and all those times it could have found itself here it is, right at the very beginning when all of this was about to start. In fact, it is even more amazing than picking one white marble from a million black ones by choosing at random. And an uneasy thought arises – perhaps our assumption about the possible choices is wrong just like it was about the bag we first thought contained a million black marbles. What would that mean – that there is no science fiction future for Humanity?


Then let's consider the alternative future where Humanity becomes extinct fairly soon. Now when we look at the probability of existing here and now it becomes extremely high, because there is no tomorrow and most of the people who will ever live are around right now. The world we see is no longer extremely improbable at all. Therefore the statistics strongly suggest that Humanity does not have much time left and there is no galaxy spanning future.


The immediate and obvious reply is that someone has to be first, which is true. It's just that it seems incredibly strange and improbable that we exist here and now since it is a very privileged position. Naturally, there is a great deal of debate over the statistics and assumptions underlying this analysis, both refuting and supporting it.


We can even put some numbers to the argument using what appear to be reasonable assumptions. I will not go into the details of the mathematics here, involving as it does Bayesian Statistics. However one set of figures suggests that Humanity has a 95% chance of extinction within the next 10,000 years. That may seem a long time, but given that our species only appeared some 100,000 years ago it means we are in the last 10% of its life. That we will not last even one thousandth as long as the dinosaurs. A rather depressing thought.


There are known to be a number of possible loopholes in the argument. For example if we assume that there are vast numbers of intelligent beings throughout the galaxy, of which we are but one, then the Doomsday Argument does not apply since our position is no longer so unusual. However, think back to the Fermi Paradox… Another possibility might be if Humanity evolved extremely rapidly into Post-Humanity, probably through genetic engineering or cybernetic symbiosis, which is something we have already examined. Even so, this might still not provide a way out of the dilemma since it is not obvious whether they too are in the same situation as us, being merely a variation on the same theme. There is also one other assumption that might not be valid, namely that all the people alive today are actually people who can be counted in the equation. For example, none of this is relevant if I live in a solipsist universe or if I am one of only a few people who are truly conscious amongst the billions around me. It is also not obvious what happens to the statistics if the Many Worlds Interpretation of Quantum Mechanics is true, and there are an infinite number of copies of me spread across the timelines. Finally there is one assumption that is made that seems so reasonable that it was not initially questioned, and that is the assumption that the universe is real. This is also tied indirectly into the other assumption made, which is that this is early 21st Century Earth. Maybe one or both of those are false, which brings us to the

The Simulation Argument [3]


Before we examine it in more detail I need to explain what is meant by the term simulation as used in a scientific or technological computing context. For example, an engineer who is designing, say, a suspension bridge will first create a mathematical model of it that runs as a computer program. The model is essentially a set of interlinked equations each of which represents the behavior of an aspect or component of the construction. Each bridge support will be defined by a list of numbers such as its dimensions, weight, material strengths in compression and tension, stiffness and so forth. All these factors are combined into a complex series of equations whose solutions provide information on what will happen to it under varying loads, and how much it will compress or deform up to and including its breaking point. There will be similar blocks of equations for each of the suspension cables and spans. The simulation of the bridge begins when various loads, representing (say) heavy trucks, are factored into the model. This can of course be represented graphically on the computer screen as a movie if need be. The idea is to make the model so accurate that it responds in exactly the same way as the real bridge when it is constructed. Of course, in this case there is no doubt that the real bridge and the simulation are utterly different. There is absolutely no chance of walking on the simulation!


However, that was a simulation of a material object whose function is to bear heavy loads. What if the simulation is of an information processing device? It could be of a pocket calculator, in which case it would have an identical functionality and identical inputs and outputs although its physical shape would obviously be different. The simulation and the “real thing” would, for all intents and purposes, be identical from a functional point of view. So, what of the current ultimate computing device, the Human brain?


Think back to a previous chapter and the example of Einstein's Brain, where each cell was replaced by a microcomputer that exactly simulated the biological counterpart. We left him functioning just as well with his mind running on silicon as it did originally using an organic substrate. From that point it is only a very short logical step to consolidate all those billions of microcomputers into one piece of software running on a single computer. We can even make a rough guess as to how much computing power is required, and it comes out at around ten thousand trillion instructions per second, that is, one followed by sixteen zeros. At the time of writing this corresponds to the equivalent of about ten thousand PCs, or ten top-of-the-range supercomputers.



Given Moore's Law, which is an observation that computing power doubles approximately every eighteen months as it has done for the past 50 years, we can see that Human equivalent computing power should be available in supercomputer form before the year 2012CE. And that it should be available on the average PC before 2030CE. Although it may require fundamental changes in technology, as it has done in the past, there is no reason why the increases in computing power should stop there. If we extrapolate to the year 2050CE, still within the lifetime of most people reading this, a PC would have the raw power capable of simulating a hundred thousand such brains. A supercomputer of that era would be capable of simulating the brain of every person on Earth simultaneously. So it is probably a fair assumption that if we have a long and prosperous future ahead of us, as a species, our computing power in (say) the year 3000CE will be vast beyond imagining.


Even now simulated realities are a big business with games constantly taking advantage of the latest increases in computing power to render ever more realistic environments in games, and Hollywood using supercomputers to create photo-realistic special effects. It will not be too long before the simulation one sees on a screen is indistinguishable from a camera pointed at a real scene, and the game will also implement physical laws and so behave like the real world. If one were to drop a simulated Human mind into that environment it may well be impossible for it to discover that it was not in the “real” reality, especially if it was surrounded by other Human, or Human level, intellects.


Bearing this in mind, the Simulation Argument runs something like this: One part of this trilemma must be true according to Bostrom:

• Almost no civilization will reach a technological level capable of producing simulated realities.

• Almost no civilization reaching aforementioned technological status will produce a simulated reality, for any of a number of reasons, such as diversion of computational processing power for other tasks, ethical considerations of holding entities captive in simulated realities, etc.

• Almost all entities with our general set of experiences are living in a simulation.

More simply stated, if someone somewhere sometime is running real-world simulations what are the chances that this reality, where I am writing this and you are reading it, is one of them? The answer depends purely on the number of such simulations. If there are none, ever, then what we see around us is certainly real. If a million such simulations are run over the lifetime of the universe, the chances of this being the real world is a million to one against.

There is a particular image conjured up in the mind when reading about realities simulated on a computer, namely that of someone sitting at a futuristic PC simulating a universe of Beings like a video game. For those of us who are older it might be a more impressive picture of some technician wearing a white lab coat supervising a giant supercomputer in a sterile air conditioned room. For those who are younger, some bored teenager playing The Sims – 2200AD in their bedroom. This will most definitely not be the case. It is ludicrous for one simple reason – that the computer itself will likely be vastly smarter than any Human alive today.

There is not going to be a future where you pop down to the local computer store and buy one of those for the kids, or to do your word processing and browse the Net. Long before that point has arisen we will have either merged with our technology and achieved some kind of apotheosis or simply been superseded by it and have become extinct, as elucidated in the Great Work (and Doomsday Argument). The only get-out would be if such simulations will never, ever, happen and the only (im)plausible reason would be if the Human mind could not be run on a computer of any type, even a synthetic biological one.

So, given a belief that such simulations will be run and that we are likely living inside one of them, only two questions remains – who and why? To examine the possibilities further we need to decide what type of simulation this world really is.

Notes

1. An estimated 1021 stars, or a billion trillion
2. The Doomsday Argument, Adam & Eve, UN++ and Quantum Joe; Nick Bostrom, Yale University
3. Bostrom, N. , 2003, Are You Living in a Simulation?, Philosophical Quarterly (2003), Vol. 53, No. 211, pp. 243-255.