An uplifting message as we enter the new year, quoted from Edge.org:
We're Not Insignificant After All
Max Tegmark, Physicist, MIT
When gazing up on a clear night, it's easy to feel insignificant. Since our earliest ancestors admired the stars, our human egos have suffered a series of blows. For starters, we're smaller than we thought. Eratosthenes showed that Earth was larger than millions of humans, and his Hellenic compatriots realized that the solar system was thousands of times larger still. Yet for all its grandeur, our Sun turned out to be merely one rather ordinary star among hundreds of billions in a galaxy that in turn is merely one of billions in our observable universe, the spherical region from which light has had time to reach us during the 14 billion years since our big bang. Then there are probably more (perhaps infinitely many) such regions. Our lives are small temporally as well as spatially: if this 14 billion year cosmic history were scaled to one year, then 100,000 years of human history would be 4 minutes and a 100 year life would be 0.2 seconds. Further deflating our hubris, we've learned that we're not that special either. Darwin taught us that we're animals, Freud taught us that we're irrational, machines now outpower us, and just last month, Deep Fritz outsmarted our Chess champion Vladimir Kramnik. Adding insult to injury, cosmologists have found that we're not even made out of the majority substance.The more I learned about this, the less significant I felt. Yet in recent years, I've suddenly turned more optimistic about our cosmic significance. I've come to believe that advanced evolved life is very rare, yet has huge growth potential, making our place in space and time remarkably significant.
The nature of life and consciousness is of course a hotly debated subject. My guess is that these phenomena can exist much more generally that in the carbon-based examples we know of.
I believe that consciousness is, essentially, the way information feels when being processed. Since matter can be arranged to process information in numerous ways of vastly varying complexity, this implies a rich variety of levels and types of consciousness. The particular type of consciousness that we subjectively know is then a phenomenon that arises in certain highly complex physical systems that input, process, store and output information. Clearly, if atoms can be assembled to make humans, the laws of physics also permit the construction of vastly more advanced forms of sentient life. Yet such advanced beings can probably only come about in a two-step process: first intelligent beings evolve through natural selection, then they choose to pass on the torch of life by building more advanced consciousness that can further improve itself.
Unshackled by the limitations of our human bodies, such advanced life could rise up and eventually inhabit much of our observable universe. Science fiction writers, AI-aficionados and transhumanist thinkers have long explored this idea, and to me the question isn't if it can happen, but if it will happen.
My guess is that evolved life as advanced as ours is very rare. Our universe contains countless other solar systems, many of which are billions of years older than ours. Enrico Fermi pointed out that if advanced civilizations have evolved in many of them, then some have a vast head start on us — so where are they? I don't buy the explanation that they're all choosing to keep a low profile: natural selection operates on all scales, and as soon as one life form adopts expansionism (sending off rogue self-replicating interstellar nanoprobes, say), others can't afford to ignore it. My personal guess is that we're the only life form in our entire observable universe that has advanced to the point of building telescopes, so let's explore that hypothesis. It was the cosmic vastness that made me feel insignificant to start with. Yet those galaxies are visible and beautiful to us — and only us. It is only we who give them any meaning, making our small planet the most significant place in our observable universe.
Moreover, this brief century of ours is arguably the most significant one in the history of our universe: the one when its meaningful future gets decided. We'll have the technology to either self-destruct or to seed our cosmos with life. The situation is so unstable that I doubt that we can dwell at this fork in the road for more than another century. If we end up going the life route rather than the death route, then in a distant future, our cosmos will be teeming with life that all traces back to what we do here and now. I have no idea how we'll be thought of, but I'm sure that we won't be remembered as insignificant.
A few thoughts: when considering the heavy skepticism that the singularity hypothesis receives, it is important to remember that there is a much weaker hypothesis, highlighted here by Tegmark, that still has extremely counter-intuitive implications about our place in spacetime; one might call it the bottleneck hypothesis - the hypothesis that 21st century humanity occupies a pivotal place in the evolution of the universe, simply because we may well be a part of the small space/time window during which it is decided whether earth-originating life will colonize the universe or not.
The bottleneck hypothesis is weaker than the singularity hypothesis - we can be at the bottleneck even if smarter-than-human AI is impossible or extremely impractical, but if smarter-than-human AI is possible and reasonably practical, then we are surely at the bottleneck of the universe. The bottleneck hypothesis is based upon less controversial science than the singularity hypothesis, and is robust to different assumptions about what is feasible in an engineering sense (AI/no AI, ems/no ems, nuclear rockets/generation ships/cryonics advances, etc) so might be accepted by a larger number of people.
Related is Hanson's "Dream Time" idea.
Tegmark:
There are at least two dubious inputs going into a statement like this. (And I see you making such a statement yourself, on your homepage, Roko!)
The first one is definitely a mistake, but perhaps not a very consequential one. Even if we accept, for the sake of argument, the proposition that the state of the visible universe indicates an absence of spacefaring intelligent life elsewhere, that is not the whole universe! All we can see is what is within our past light-cone. We have no information on what has happened in those galaxies since then - and in some cases, we are referring to billions of years. And then there's the whole rest of the universe, possibly infinite in extent, with which we have not yet interacted.
So the idea that the future of the entire cosmos hinges on what happens on Earth in the next few years is hyperbole, even if one accepts the usual premises.
The second dubious ingredient to these judgments is the premise itself. I discern two arguments in favor of the proposition that the universe is empty of intelligent life (among people who make statements like this):
1) The visible universe appears to be explicable entirely in terms of natural astrophysical structures. If there were galactic intelligences, they wouldn't let the stars shine freely into space, they'd surround them with Dyson spheres so as to harvest that radiative output for computational or other purposes, or they would otherwise engage in works of astrophysical engineering.
2) If Earth was in a region of space controlled by an alien intelligence, life, history, and evolution as we know it would not have happened. There would have been some sort of intervention, whether benevolent, or just to appropriate the atoms of this solar system for technological projects and other alien purposes.
Argument 1 is interesting but not exactly conclusive. Lots of the universe is dark matter. It may be that the dark matter has been appropriated by spacefaring intelligences and used so as to make every photon count, and that the regions of the universe which are visibly emitting light are interzones - demilitarized wilderness areas, regions where an aeon-long process of scouting and negotiation is occurring, and so forth. In fact, I find this interpretation rather more sensible than the assumption of a wholly uninhabited universe. But it's still very hypothetical. It's hard to even comprehensively list all the uncertainties which one must guess about in order to produce scenarios like this. You need to guess at the frequency with which spacefaring intelligence appears in the universe, the frequency with which it becomes expansionist, the difficulties associated with expansion, the stability of value systems and civilizational tendencies over million-year periods (if a super-civilization decides to end itself, it should be good at doing so; suicidal tendencies only have to rise to the top once; and millions of years offers a very long time for them to do so).
As for argument 2, well, there are certainly alien value systems which would leave us alone, though I have no idea how likely such value systems are to arise. But in any case, the idea that we are in a wilderness area between the local dark-matter civilizations is sufficient to explain why we've been left alone, without having to posit a completely empty universe.
This is not consistent with the spatial placement of bright versus dark matter - you'd expect the interzones to occur as thin surfaces, rather like boundries between bubbles. In reality, you find a bright galaxy with a doughnut-shaped halo of dark matter around it, and you find that around every visible galaxy, repeated again, and again and again. Y... (read more)