Last year at this time I tackled the question: How will our Universe die?
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An interesting theory has emerged which predicts that trillions of years into the future, the information that currently allows us to understand how the universe expands will have disappeared over the visible horizon. All that will remain will be "an island universe" made from the Milky Way and its nearby galactic Local Group neighbors. What's left will be a dark and lonely void.
The theory was put out by physicists Lawrence Krauss from Case Western Reserve University and Robert J. Scherrer from Vanderbilt University. Their research article, titled, "The Return of the Static Universe and the End of Cosmology," will be published in the October issue of the Journal of Relativity and Gravitation.
This brings to mind a number of different theories in the field of cosmological eschatology.
The Big Crunch
The work of Krauss and Scherrer stands in sharp contrast to another end-state theory, namely the Big Crunch. In this model, the momentum of the Big Ban will eventually wane causing the Universe to collapse in on itself. But due to the recent revelation that the Universe is not just expanding but that its expansion is speeding up, newer theories have suggested that the Universe will continue to expand forever.
The Big Rip
This has lead to some rather bizarre conclusions, including the emergence of a theory known as the Big Rip. According to this theory, the Universe will start to expand at such a rapid rate that all its elements, from galaxies to atoms, will be torn apart by the extreme expansion rate of the Universe. This is scheduled to happen about 20 billion years from now.
The force that is causing the Universe's matter to push outwards is what's known as dark energy. This is why galaxies are moving away from each other -- and why they will continue to do so until gravity will be too weak to hold them together.
Eventually, in the final months of the Universe, our solar system will be gravitationally unbound. In the last minutes, stars and planets will be torn apart. And in the Universe's final spastic salvo all atoms will be destroyed.
Heat Death
Another possibility is the Heat Death of the Universe, also known as The Big Freeze. In this model the Universe would continue to expand forever, but it would enter into a state of maximum entropy in which all matter and energy is evenly distributed; consequently, there would be no 'gradient' to the Universe -- a characteristic that is needed to sustain information processing, including life.
Other theories
Other possibilities include the False Vacuum, where the laws and constants of the Universe are subject to radical change, and various multiverse theories in which the cosmos is expressed in a infinite number of iterations for an infinity.
Another more radical possibility is that the future of the Universe will be influenced by intelligent life. Theories already exist in regards to stellar engineering -- where a local sun could be tweaked in such a way as to extend its lifespan. Future civilizations may eventually figure out how to re-engineer the Universe itself (such as re-working the constants) or create an escape hatch to basement universes.
Thinkers who have explored this possibility include Milan Cirkovic, John Smart, Ray Kurzweil, Alan Guth and James N. Gardner.
Read more here.
Saturday, May 24, 2008
One year ago on SentDev: How will our Universe die?
Saturday, May 10, 2008
One year ago on SentDev: When hypergiants go hypernova
It was about a year ago around this time that scientists observed a star that went nova 238 million years ago. It turned out to be a hypernova that made a big badda boom.
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Scientists predicted that something like this could happen, and now they have actually observed it: a hypergiant star went nova.
About 238 million years ago a star in galaxy NGC 1260 ended its life. To say that it was a powerful explosion would be a gross understatement; the amount of explosive energy expelled by supernova SN 2006gy defies human comprehension.
Prior to its dramatic death, the hypergiant star, which was 150 times larger than our own, suffered a sudden and violent collapse. Extremely high levels of gamma radiation from the star's core caused its energy to transform to matter, and the drop in energy in turn caused the star to collapse. This resulted in a dramatic increase in the thermonuclear reactions that was burning within it. All this added energy overpowered the gravitational attraction causing the star to explode.
And explode it did.
Scientists claim that the supernova was over 150 times more powerful than any other observed to date. Physical models suggested that such a supernova was theoretically possible, but astronomers believed that such events were limited to the early Universe when stars tended to be hypergiant.
A hypernova like SN 2006gy can instantly expel about 10X46 joules. This is more energy than our sun produces over a period of 10 billion years.
According to the Astroprof blog,
At discovery, it was already as bright as a Type Ia supernova at its peak. But, instead of getting dimmer, SN 2006gy continued to get brighter for several weeks. The peak brightness seldom comes much more than a week after the explosion. Theoretical models suggest that SN 2006gy gets its light from both the expanding cloud of gas and a shock front as the cloud of gas expands into very dense gasses surrounding the progenitor star. But, the expanding gas cloud is so bright that it requires substantially more radioactive decay to heat it that would be present in almost any other supernova. The best way to get that much radioactive material, according to the model that the theorists have come up with, is for basically the whole core to be thrown out into the supernova, leaving little or nothing behind to form a neutron star or black hole. So much material is thrown out, that the supernova continues to be heated long after the explosion itself. In fact, even months later, SN 2006gy has faded in brightness only to as bright as the peak brightness of a Type Ia supernova!In fact, astronomers were able to observe the hypernova's peak brightness for an astounding 70 days.
Supernovas can wreak tremendous havoc in its local area, effectively sterilizing the region. These explosions produce highly collimated beams of hard gamma rays that extend outward from the exploding star. Any unfortunate life-bearing planet that should come into contact with those beams would suffer a mass extinction (if not total extinction depending on its proximity to the supernova). Gamma rays would eat up the ozone layer and indirectly cause the onset of an ice age due to the prevalence of NO2 molecules.
Supernovas can shoot out directed beams of gamma rays to a distance of 100 light years, while hypernovas and gamma ray bursts can impact areas as far as 500 light years away.
Thankfully, hypergiant Eta Carinae, which is on the verge of going nova, is well over 7,500 light years away from Earth. We'll be safe when it goes off, but you'll be able to read by its light at night-time.
Tuesday, March 18, 2008
Latest podcast posted: 2008.03.18
The latest episode of the Sentient Developments Podcast is now available. Alternative audio formats are also available.
This episode: The Fermi Paradox is back with a vengeance, nanotechnology will reshape humanity, and why evolutionary psychology says we should cut Spitzer some slack.
Monday, August 06, 2007
The Fermi Paradox: Possible solutions and next steps
This article is partly adapted from my TransVision 2007 presentation, “Whither ET? What the failing search for extraterrestrial intelligence tells us about humanity's future.”
In my previous two articles I attempted to re-affirm the Fermi Paradox (FP) and circumscribe some of the possible interstellar activities and developmental aspects of advanced extraterrestrial intelligences (ETI’s).
In this article I will offer two broad solutions to the FP: 1) unavoidable self-destruction and 2) localized non-migratory existence.
It is not my intention at this time to provide a complete list of possible reconciliations, nor am I claiming to have found any kind of special answer; I just wish to explore these two particular possibilities.
At the conclusion of this article I offer some suggestions to help us move forward as we work to solve the observational problem that is the Great Silence.
Self-Destruction and the Great Filter
This is the most likely and philosophically satisfying answer to the Fermi Paradox – although hardly the most desirable.
Looking at ourselves as a typical example of a pre-Singularity civilization, what do we find? We find a species already in possession of apocalyptic technologies and on the verge of developing an entirely new generation of lethal weapons. In short order we will be required to manage an assortment of apocalyptic technologies; it will be akin to spinning plates. There are only so many that can be managed before one of them falls – and one is all that is needed to end the story.
Examples of pending existential risks include the ongoing threat of nuclear holocaust, a nanotechnological disaster, poorly programmed artificial superintelligence (ie Singularity as extinction event), catastrophic pandemic, and so on.
A counter-argument is often made that self-inflicted catastrophism could never be exclusive to all civilizations. How is it, ask critics, that all civilizations cannot escape such a fate? Robin Hanson attempted to answer this question by proposing the Great Filter hypothesis – the suggestion that a developmental stage exists for all life which is insurmountable. The question then: is the Great Filter behind us, or does it await us in our future?
I would argue, based on much of the data I presented earlier, that the Rare Earth hypothesis has to be rejected. Moreover, a healthy application of the self-sampling assumption strongly indicates that the filter is ahead of us should it exist. The Galaxy is likely brimming with life, including complex life.
As for as the search for extraterrestrial life is concerned, Hanson argues that the detection of ETI's would be bad. This would indicate, given our observation of an unperturbed, uncolonized galaxy, that the Great Filter is indeed still ahead of us.
Another disturbing data point as a self-sampling species is that we here on earth have come to possess apocalyptic technologies long before we have developed the capacity to live off-planet or live in self-contained biospheres. All our eggs are in one basket and they will continue to remain that way into the foreseeable future.
And then there's the disturbing Doomsday Argument which suggests that we're closer to the end than the beginning of human civilization.
Perhaps the most common and smug solution to the Fermi Paradox is the suggestion that we are the first. It is frequently used because it is said to best satisfy Occam’s Razor. But while it may be the simplest solution, it defies our sense of probability and disregards the central lesson of the Copernican Principle – the idea that we are not unique, and very likely a typical example.
Earlier I presented a picture of a biophilic Universe. If this issue is to be settled by a battle between Occam’s Razor and the Copernican principle, on this matter I’ll take Copernicus any day.
Interestingly, the longer we survive as a species without extraterrestrial contact, the more we can assume that we have passed the Great Filter.
Localized non-migratory digital existence
Now, the prospect of human extinction is quite obviously mere speculation. As Morpheus proclaimed in the Matrix: “We are still here!” Consequently, there are some non-extinction scenarios that I would like to explore.
The past 40 years of scientific progress has forced a re-evaluation of humanity’s potential. We appear to be headed for a transformation that takes us away from biological existence and towards a postbiological, or digital existence. Our future visions must take this into account. As Milan Cirkovic and Robert Bradbury have noted, we need to adopt a digital perspective (pdf).
Why leave the local system when everything can be accomplished at home? Localized existence may hold promise for all the aspirations that an advanced intelligence could conceivably conjure.
Specifically, advanced intelligences may engage in computational megaprojects and live virtual reality existences. It would be an existential phase transitioning into virtual space such that interstellar colonization would never emerge as a feasible option or experiment.
For example, advanced ETI’s may construct Jupiter (pdf) and Matrioshka Brains. A Jupiter Brain would utilize all the matter of entire planet for the purpose of computation, while a Matrioshka Brain (a kind of Dyson sphere) would utilizes the energy output of its parent star.
Determining an upper bound for computational power is difficult, but a number of thinkers have given it a shot. Eric Drexler has outlined a design for a system the size of a sugar cube that would perform 10^21 instructions per second. Robert Bradbury gives a rough estimate of 10^42 operations per second for a computer with a mass on order of a large planet. Seth Lloyd calculates an upper bound for a 1 kg computer of 5*10^50 logical operations per second carried out on ~10^31 bits – this would likely be done on a quantum computer or computers built of out of nuclear matter or plasma [see this article and this article for more information].
More radically, John Barrow has demonstrated that, under a very strict set of cosmological conditions, indefinite information processing (pdf) can exist in an ever-expanding universe.
This type of computational power is astounding and defies human comprehension. It’s like imagining a universe within a universe -- and that may be precisely be how it's used.
What would a future civilization do with all this power?
A civilization’s transition into high-speed digital mode may come about as natural consequence of its development. The switch from an analog civilization to a digital one – one in which the clock-speed would be accelerated to billions if not trillions of times faster than before – would preclude the desire to interact with the outside world.
Megascale computers may be used to support uploaded civilizations. It may prove to be the existential substrate of choice – one in which the potential for self-destruction is greatly mitigated.
Advanced civilizations may also use this computer power to run simulations for reasons of scientific research, running ancestor simulations or for entertainment (pdf) purposes. Simulations may also be run as a part of some sort of ethical or sociological necessity.
Another possibility is the Hedonistic Imperative, a term attributed to David Pearce. Given that virtually every religion has fantasized about an afterlife of bliss and an end to suffering, paradise engineering may come to represent the optimal end-state for intelligent life. Ultimately, societies will always be comprised of conscious individuals. The optimization of subjective experience may take precedence over colonial ambitions.
This tendency may be part of a broader, more 'existential' focus on life. Civilizational achievement may not be measured by the rate of imperialistic expanse or by how much energy it can consume, but in how individuals relate to themselves and their place in the Universe. This quest for introspective enlightenment may be characterized by efforts to optimize the mode of conscious experience.
What about long term survival?
In regards to long-term survival, Vernor Vinge has predicted that post-Singularity intelligences will build local secondary systems to ensure the near-immortality of the infocomplex. These could exist in off-planet repositories. Shields composed of nanotechnology and femtotechnology could deal with the issue of gamma ray bursters and other cosmological threats.
As for the local star, it could be given added life through stellar-engineering projects in which the crucially low elements are re-introduced. Eventually, however, migration to a younger star would be necessary.
There may also be unknown reasons for this type of existence. But what is certain is that wide-scale colonization is not in the cards.
Moving Forward
Admittedly, these two broad solutions -- self-destruction and non-migration scenarios -- are unsatisfactory. The notion that not even one civilization can escape self-destruction is difficult to believe. Moreover, localized digital existence and the proliferation of colonization waves are not either/or scenarios; one can imagine a civilization embarking on both paths.
As we move forward in attempting to solve the FP we need to apply much stricter methodologies to the problem.
Solutions to the FP must avoid the trappings of sociological analyses, which often present non-exclusive scenarios. Answers like the ‘zoo hypothesis,’ ‘non-interference,’ or ‘they wouldn’t find us interesting,' tend to be projections of the human psyche and our own modern-day realities. Moreover, these sorts of solutions, while they may account for some of the actions of advanced civilizations, cannot account for all.
Instead, a more rigid and sweeping methodological frame needs to be applied– one which takes cosmological determinism and sociological uniformitarianism into account. In other words, we need to be concerned with cosmological limits and the pressure of physical and resource constraints.
This is what is Nick Bostrom refers to as the strong convergence hypothesis -- the idea that all sufficiently advanced civilizations converge towards the same optimal state. This is a hypothesized developmental tendency akin to a Dawkinsian fitness peak -- the suggestion that identical environmental stressors, limitations and attractors will compel intelligences to settle around optimal existential modes. This theory does not favour the diversification of intelligence – at least not outside of a very strict set of living parameters.
The trick will be to predict what these deterministic constraints are. One can imagine factors such as limited resources, access to energy, computational requirements (including heat dissipation, error correction, and latency problems) and self-preservational modes (i.e. political and social orientations that eliminate the possibility of self-destruction).
A side benefit of this exercise is that it doubles as a foresight activity. The better we become at predicting the make-up of advanced ETI's, the better we will be at predicting our own future.
Consequently, our very own survival may depend on it.
Sunday, August 05, 2007
The Fermi Paradox: Advanced civilizations do not…
This article is partly adapted from my TransVision 2007 presentation, “Whither ET? What the failing search for extraterrestrial intelligence tells us about humanity's future.”
As I stated in my previous article, “The Fermi Paradox: Back with a vengeance”:The fact that our Galaxy appears unperturbed is hard to explain. We should be living in a Galaxy that is saturated with intelligence and highly organized. Thus, it may be assumed that intelligent life is rare, or, given our seemingly biophilic Universe, our assumptions about the general behaviour of intelligent civilizations are flawed.
So, let’s try to figure out what’s going on. Given the Great Silence, and knowing what we may be capable of in the future, we can start to make some fairly confident assumptions about the developmental characteristics of advanced civilizations.
A paradox is a paradox for a reason: it means there’s something wrong in our thinking.
But rather than describe the possible developmental trajectories of extraterrestrial intelligences (ETI's) (a topic I’ll cover in my next article), I’m going to dismiss some commonly held assumptions about the nature of advanced ETI’s – and by consequence some assumptions about our very own future.
Advanced civilizations do not…
…advertise their presence to the local community or engage in active efforts to contact
As SETI is discovering (but is in denial about), space is not brimming with easily detectable radio signals. SETI’s work during the past 40 years indicates that the quest to detect signals will not be easy.
This problem is not as simple as it sounds. A common apology is that we’ve only recently started our search and we have only scratched the surface. The trouble, however, is that it would be no problem for an ETI to communicate with us if they wanted to.
To do this all they would need to do is seed the Galaxy with Bracewell probes (a self-replicating communications beacon). This scenario was explored in Carl Sagan’s Contact in which a Bracewell probe was lying in wait about 26 light years from Earth in the Vega system. The probe was activated by our radio signals, causing it to direct powerful radio signals at Earth – signals that would not be overlooked.
We know that no such object exists in our solar system or within a radius of about 25 to 50 light years. Our radio activity should have most certainly activated any probe lying dormant in our local vicinity by know. It is also reasonable to assume that if ETI’s embarked on such a communications mission that every solar system would likely have its own Bracewell probe.
Which in turn raises a more troubling question: if ETI’s could construct and distribute probes in this way, why haven’t they gone the extra mile and spread other types of self-replicating devices such as uplift or colonization probes?
…engage in any kind of megascale engineering or stellar re-engineering that is immediately obvious to us within our light cone
All stellar phenomenon that we have observed to this point in time appears ‘natural’ and unmodified. We see no clusters of perfectly aligned stars, nor do we signs of Kardashev III civilizations utilizing the energy output of the entire Milky Way.
As for our light cone, the Milky Way is 100,000 light years in diameter; given the possibility that our Galaxy has been able to support intelligent life for about 4.5 billion years, a 100 million year time lag (at its worst) is not severe enough to cause observational problems (except for distant Galaxies).
…colonize the Galaxy 
Our Galaxy remains uncolonized despite the theoretical potential for advanced ETI’s to do so – namely the time and the technology. All that would be required is a self-replicating Von Neumann probe that proliferates outward at an exponential rate. Technologies required to build such a spacecraft would include artificial intelligence, molecular assembling nanotechnology, and an advanced propulsion scheme like anti-matter rockets, beamed energy, or interstellar ram-jets.
The reason for non-colonization is not obvious (hence the Fermi Paradox). In addition to technological feasibility there is the issue of economic and sociological imperatives for colonization.
…sterilize the Galaxy
Finally, some good news. We know the Galaxy is not sterile because we exist here on Earth.
Like the colonization potential, the prospect for an advanced ETI to sterilize the Galaxy exists through the use of berserker probes (a term attributed to Fred Saberhagen). These probes could steer NEO’s at planets, unleash nanotechnological phages, or toast planets with directed beams of highly concentrated light.
And like the Bracewell scenario, if a beserker was lying dormant in our solar system it should have destroyed us by now. If sterilization is the goal, there is no good reason for it to wait – particularly as our own civilization hurtles towards a Singularity transition.
Reasons for unleashing fleets of berserkers can be conceived, including xenophobic sociological imperatives or a malign artificial superintelligence (pdf). And all it would take is one civilization to do it. But as Robert Freitas has stated, "The present observational record can only support the much more restricted conclusion that no rapacious galactic civilisations are currently loose in the Galaxy."
…uplift or interact with pre-Singularity intelligences and biospheres
As a civilization that has been left to fend for itself, we have to assume that we, like any other civilization out there, goes it alone. No one is coming to help us. The Great Silence will continue.
Moreover, our presence on Earth and our civilizational development can be explained by naturalistic phenomena. Our existence and ongoing progress has been devoid of extraterrestrial interventions. If we’re going to survive the Singularity, or any other existential risks for that matter, it will have to be of our own devices.
…re-engineer the cosmos
A number of prominent futurists, a list that includes Ray Kurzweil and Hans Moravec, have speculated that the destiny of advanced intelligence is to re-work the cosmos itself. This has been imagined as an ‘intelligence explosion’ as advanced life expands outward into the cosmos like a bubble. The entire Galaxy would be re-organized with much of its matter converted into computronium. Eventually, it is thought that the laws of the Universe will be re-tuned to meet the needs of advanced civilizations.
Unfortunately, we do not appear to inhabit a Universe that even remotely resembles this model. The cosmos appears natural and unperturbed.
This is reminiscent of the God problem and the presence of evil. We live in a Universe that is hostile, indifferent and pointless. If advanced ETI’s had the capacity to re-engineer the Universe such that it was safer, more meaningful and paradisical they would have done so by now. By virtue of the fact that we observe such a dangerous Universe we should probably conclude that such a project is not an option.
In the final part of this series I will make an effort to explain why advanced civilizations don’t do these things and what they might be doing instead.
Saturday, August 04, 2007
The Fermi Paradox: Back with a vengeance
To deal with the cognitive dissonance created by the Great Silence, we have resorted to good old fashioned human arrogance, anthropocentrism, and worse, an inter-galactic inferiority complex. We make excuses and rationalizations like, ‘we are the first,’ ‘we are all alone,’ or, ‘why would any advanced civilization want to bother with us backward humans?’
Under closer scrutiny, however, these excuses don’t hold. Our sciences are steadily maturing and we are discovering more and more that our isolation in the cosmos and the dearth of observable artificial phenomenon is in direct violation of our expectations, and by consequence, our own anticipated future as a space-faring species.
Indeed, one of the greatest philosophical and scientific challenges that currently confronts humanity is the unsolved question of the existence of extraterrestrial intelligences (ETI's).
We have yet to see any evidence for their existence. It does not appear that ETI’s have come through our solar system; we see no signs of their activities in space; we have yet to receive any kind of communication from them.
Adding to the Great Silence is the realization that they should have been here by now -- the problem known as the Fermi Paradox.
The Fermi Paradox
The Fermi Paradox is the contradictory and counter-intuitive observation that we have yet to see any evidence for the existence of ETI’s. The size and age of the Universe suggests that many technologically advanced ETI’s ought to exist. However, this hypothesis seems inconsistent with the lack of observational evidence to support it.
Largely ignored in 1950 when physicist Enrico Fermi famously asked, “Where is everybody,” and virtually dismissed at the seminal SETI conference in 1971, the conundrum was given new momentum by Michael Hart in 1975[1] (which is why it is sometimes referred to as the Fermi-Hart Paradox).
Today, 35 years after it was reinvigorated by Hart, it is a hotly contested and relevant topic -- a trend that will undoubtedly continue as our sciences, technologies and future visions develop.
Back with a vengeance
A number of inter-disciplinal breakthroughs and insights have contributed to the Fermi Paradox gaining credence as an unsolved scientific problem. Here are some reasons why[2]:
The scale of our cosmological environment is coming into focus. Our Universe contains about 10^11 to 10^12 galaxies, giving rise to a total of 10^22 to 10^24 stars[3]. And this is what exists right now; there have been a billion trillion stars in our past Universe. [4]
Improved understanding of planet formation, composition and the presence of habitable zones
The Universe formed 13.7 billion years ago. The Milky Way Galaxy formed a mere 200 million years later, making our Galaxy nearly as old as the Universe itself. Work by Charles Lineweaver has shown that planets also began forming a very long time ago; he places estimates of Earth-like planets forming 9 billion years ago (Gyr).
According to Lineweaver, the median age of planets in the Galaxy is 6.4+/0.7 Gyr which is significantly more than the Earth’s age. An average terrestrial planet in the Galaxy is 1.6 Gyr older than the Earth. It is estimated that three quarters of earth-like planets in the Galactic habitable zone are older than the Earth.
We have a growing conception of where habitation could be sustained in the Galaxy. The requirements are a host star that formed between 4 to 8 Gyr ago, enough heavy elements to form terrestrial planets, sufficient time for biological evolution, an environment free of sterilization events (namely super novae), and an annular region between 7 and 9 kiloparsecs from the galactic center that widens with time. [6]
The discovery of extrasolar planets
Over 240 extrasolar planets have been discovered as of May 1, 2007[7]. Most of these are so-called “hot Jupiters,” but the possibility that their satellites could be habitable cannot be ruled out. Many of these systems have stable circumstellar habitable zones.
Somewhat shockingly, the first Earth-like planet was discovered earlier this year orbiting the red star Gilese 581; it is 20 light years away, 1.5 times the diameter of Earth, is suspected to have water and an atmosphere, and its temperature fluctuates between 0 and 40 degrees Celsius.[8]
Confirmation of the rapid origination of life on Earth
The Earth formed 4.6 Gyr ago and rocks began to appear 3.9 Gyr ago. Life emerged quickly thereafter 3 Gyr ago. Some estimates show that life emerged in as little as 600 million years after the formation of rocks.[9]
Growing legitimacy of panspermia theories
There is a very good chance that we inhabit a highly compromised and fertile Galaxy in which ‘life seeds’ are strewn about. The Earth itself has been a potentially infectious agent for nearly 3 billion years.
Evidence has emerged that some grains of material in our solar system came from beyond our solar system. Recent experiments show that microorganisms can survive dormancy for long periods of time and under space conditions. We also now know that rocks can travel from Mars to Earth.[10]
Discovery of extremophiles
Simple life is much more resilient to environmental stress than previously imagined. Biological diversity is probably much larger than conventionally assumed.
Developing conception of a biophilic Universe in which the cosmological parameters for the existence of life appear finely tuned
As scientists delve deeper and deeper into the unsolved mysteries of the Universe, they are discovering that a number of cosmological parameters are excruciatingly specific. So specific, in fact, that any minor alteration to key parameters would throw the entire Universe off kilter and result in a system completely unfriendly to life. The parameters of the Universe that are in place are so specific as to almost suggest that spawning life is in fact what the Universe is supposed to do. [11]
Cosmological uniformitarianism implies that that anthropic observation need not be and cannot be specific to human observers, but rather to any observer in general; in other words, the Universe can support the presence of any kind of observer, whether they be here on Earth or on the other side of the cosmos.
Confirmation of the early potential for intelligent life
My own calculations have shown that intelligence could have first emerged in the Universe as long as 4.5 Gyr ago -- a finding that is consistent with other estimates, including those of Lineweaver and David Grinspoon.[12]
Refinement of evolutionary biology, computer science and systems theories
Evolution shows progressive trends towards increasing complexity and in the direction of increasing fitness. There has also been the growing acceptance of Neo-Darwinism.
Advances in computer science have reshaped our conception of what is possible from an informational and digital perspective. There is the growing acceptance of systems theories which take emergent properties and complexity into account. Game theory and the rise of rational intelligence add another level to this dynamic mix.
Development of sociobiological observations as they pertain to the rapid evolution of intelligent life and the apparent radical potential for advanced intelligence
Exponential change.
And then there is the theoretic potential for a technological Singularity, digital minds, artificial superintelligence, molecular nanotechnology, and other radical possibilities. There is also emerging speculation about the feasibility of interstellar travel, colonization and communication.
In other words….
There are more stars in the Universe than we can possibly fathom. Any conception of ‘rare,’ ‘not enough time’ or ‘far away’ has to be set against the inability of human psychology to grasp such vast cosmological scales and quantities. The Universe and the Milky Way are extremely old, our galaxy has been able to produce rocky planets for quite some time now, and our earth is a relative new-comer to the galaxy.
The composition of our solar system and the Earth itself may not be as rare as some astronomers and astrobiologists believe. These discoveries are a serious blow to the Rare Earth Hypothesis – the idea that the genesis, development and proliferation of life is an extremely special event[13]. It’s also a blow to Brandon Carter’s anthropic argument which takes a very human-centric approach to understanding cosmology, suggesting that our existence as observers imposes the sort of Universe that only we can observe.
Finally, the Universe appears capable of spawning radically advanced intelligence – the kind of advanced intelligence that transhumanists speculate about, namely post-Singularity, post-biological machine minds. Given intelligent life's ability to overcome scarcity, and its tendency to colonize new habitats, it seems likely that any advanced civilization would seek out new resources and colonize first their star system, and then surrounding star systems. Indeed, estimates place the time to colonize the Galaxy anywhere from one million to 100 million years.[14]
The fact that our Galaxy appears unperturbed is hard to explain. We should be living in a Galaxy that is saturated with intelligence and highly organized. Thus, it may be assumed that intelligent life is rare, or, given our seemingly biophilic Universe, our assumptions about the general behaviour of intelligent civilizations are flawed.
A paradox is a paradox for a reason: it means there’s something wrong in our thinking.
So, where is everybody?
[1] Hart, M. H. "An Explanation for the Absence of Extraterrestrial Life on Earth," Quarterly Journal of the Royal Astronomical Society, 16, 128-135 (1975).
[2] This list, which is not intended to be a complete re-affirmation of the Fermi Paradox, was inspired and partly adapted from: Ćirković , Milan M. and Bradbury, Robert J. "Galactic Gradients, Postbiological Evolution and the Apparent Failure of SETI", New Astronomy, vol. 11, pp. 628-639 (2006).
[3] "How many stars are there in the Universe?" European Space Agency, Space Scientist, February 23, 2004: http://www.esa.int/esaSC/SEM75BS1VED_index_0.html.
[4] Hanson, R. 1999, “Great Filter,” (preprint at http://hanson.berkeley.edu/greatfilter.html).
[5] See Harvey Mudd and S. E. Levine: “Mass of the Milky Way and Dwarf Spheroidal Stream Membership.”
[6] Gonzalez, G., Brownlee, D., and Ward, P. 2001, “The Galactic Habitable Zone: Galactic Chemical Evolution,” Icarus 152, 185-200; Lineweaver, Charles H., Fenner , Yeshe, and Gibson, Brad K. 2004, “The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way.”; M. Noble , Z. E. Musielak , and M. Cuntz: 2002, "Orbital Stability of Terrestrial Planets inside the Habitable Zones of Extrasolar Planetary Systems"
[7] "A Rush of New Planets," Astrobiology Magazine: Jun 02, 2007: http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=2351
[8] "All Wet? Astronomers Claim Discovery of Earth-like Planet," Scientific American, April 24, 2007: http://www.sciam.com/article.cfm?articleID=25A261F0-E7F2-99DF-313249A4883E6A86&chanID=sa007
[9] See Stephen J. Mojzsis: http://spot.colorado.edu/~mojzsis/
[10] Raulin-Cerceau, F., Maurel, M.-C., and Schneider, J. 1998, “From panspermia to bioastronomy, the evolution of the hypothesis of universal life,” Orig. Life Evol. Biosph. 28, 597; "Encore: Great Debates Part VI," Astrobiology Magazine, Aug 19, 2002: http://www.astrobio.net/news/article254.html
[11] The Wikipedia entry on the Fine Tuning argument has some good links and references: http://en.wikipedia.org/wiki/Fine-tuned_universe
[12] Dvorsky, George: 2006, “When Did Intelligent Life First Emerge in the Universe?” http://sentientdevelopments.blogspot.com/2006/06/when-did-intelligence-first-emerge-in.html;
[13] Ward, P. D. and Brownlee, D. 2000, Rare Earth: Why Complex Life Is Uncommon in the Universe (Springer,
[14] Ćirković ,
Wednesday, July 11, 2007
Striz: Why does something exist instead of nothing?
Martin Striz is wondering why existence should exist. As usual, he and I are on the same wavelength.
Thursday, May 31, 2007
The Drake Equation is obsolete
I'm surprised how often the Drake Equation is still mentioned when people discuss such things as the search for extra terrestrial intelligence (SETI), astrobiology and problems like the Fermi Paradox.
Fairly recent insights in such fields as cosmology, astrobiology and various future studies have changed our perception of the cosmos and the ways in which advanced life might develop.
Frank Drake's equation, which he developed back in 1961, leaves much to be desired in terms of what it's supposed to tell us about both the nature and predominance of extraterrestrial life in our Galaxy.
The Drake Equation
The Drake equation states that:
where:
N is the number of civilizations in our galaxy with which we might hope to be able to communicate and:
R* is the average rate of star formation in our galaxyArbitrary at best
fp is the fraction of those stars that have planets
ne is the average number of planets that can potentially support life per star that has planets
fl is the fraction of the above that actually go on to develop life at some point
fi is the fraction of the above that actually go on to develop intelligent life
fc is the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L is the length of time such civilizations release detectable signals into space.
The integers that are plugged into this equation are often subject to wide interpretation and can differ significantly from scientist to scientist. Even the slightest change can result in vastly different answers. Part of the problem is that our understanding of cosmology and astrobiology is rapidly changing and there is often very little consensus among specialists as to what the variables might be.
Consequently, the Drake formula relies on 'stabs in the dark.' This makes it highly imprecise and unscientific. The margin of error is far beyond what should be considered acceptable or meaningful.
No accounting for cosmological development or time
Another major problem of the Drake Equation is that it does not account for two rather important variables: cosmological developmental phases and time (see Cirkovic, "The Temporal Aspect of the Drake Equation and SETI").
More specifically, it does not take into consideration such factors as the age of the Galaxy, the time at which intelligence first emerged, or the presence of physiochemical variables necessary for the presence of life (such as metallicity required to form planets). The equation assumes a sort of cosmological uniformity rather than a dynamic and ever changing universe.
For example, the equation asks us to guess the number of Earth-like planets, but it does not ask us when there were Earth-like planets. And intelligence itself may have been present as long as 2 to 4.5 billion years ago.
The Galaxy's extreme age and the potential for intelligence to have emerged at disparate points in time leaves an absurdly narrow window for detecting radio signals. The distances and time-scales in question are mind-boggingly vast. SETI, under its current model, is conducting an incredibly futile search.
Detecting ETI's
Which leads to the next problem, that of quantifying the number of radio emitting civilizations. I'm sure that back in the 1960's it made a lot of sense to think of radio capability as a fairly advanced and ubiquitous means of communication, and by consequence, an excellent way to detect the presence and frequency of extraterrestrial civilizations.
But time has proven this assumption wrong. Our radio window is quickly closing and it will only be a matter of time before Earth stops transmitting these types of signals -- at least unintentionally (active SETI is a proactive attempt to contact ETI's with radio signals).
Due to this revelation, the entire equation as a means to both classify and quantify certain types of civilizations becomes quite meaningless and arbitrary. At best, it's a way of searching for a very narrow class of civilizations under very specific and constrained conditions.
Rather, SETI should continue to redefine the ways in which ETI's could be detected. They should try to predict future means of communication (like quantum communication schemes) and ways to identify these signals. They should also look for artificial objects such as megascale engineering and artificial calling cards (see Arnold, "Transit Lightcurve Signatures of Artificial Objects").
The future of advanced intelligence
Although possibly outside the auspices of this discussion, the Drake Equation does not account for the presence of post-radio capable civilizations, particularly post-Singularity machine intelligences. This is a problem because of what these types of civilizations might be capable of.
The equation is used to determine the number of radio capable civilizations as they conduct their business on their home planet. Again, this is a vary narrow view of ETI's and the space of all possible advanced civilizational types. Moreover, it does not account for any migratory tendency that advanced civs may have.
The Drake Equation does not tell us about exponential civilizational growth on account of Von Neumann probe disbursement. It does not tell us where advanced ETI's may be dwelling or what they're up to (e.g. Are they outside the Galaxy? Do they live inside Jupiter Brains? Do they phase shift outside of what we regard as habitable space? etc.). This is a serious shortcoming because the answers to these questions should help us determine not just where we should be looking, but they can also provide us with insight as to the makeup of advanced intelligence life and our own potential trajectory.
In other words, post-Singularity ETI's may represent the most common mode of existence for late-stage civilizations. And that's who we should be looking for rather than radio transmitting civs.
Are we alone?
Michael Crichton once put out a very weak argument against the Drake Equation. He claimed that SETI was a religious endeavor because it was a search for imaginary entities. He is wrong, of course; we should most certainly search for data where we think we might find it. I believe, despite the low odds, that it is reasonable to assume that our search for life on other planets is warranted. Even a negative result can be meaningful.
Consequently, SETI should keep listening, but expect to hear nothing. If we should suddenly hear something from the depths of space, then we will have to seriously re-evaluate our assumptions.
At the same time we should find better ways to detect advanced life and tweak the Drake Equation in such a way as to account for the missing variables and factors I mentioned earlier.
Again, and more generally, we should probably adopt the contact pessimist's frame. Back in the 60's and 70's, when the contact optimists like Sagan, Shklovskii and Drake ruled the Earth, it was not uncommon to think that N in the equation fell somewhere between 10x6 to 10x9.
These days, in the post Tipler and Hart era of astrosociobiology, cosmologists and astrobiologists have to take such factors into consideration as Von Neumann probes, the Fermi Paradox, the Rare Earth Hypothesis, stronger variants of the anthropic principle and catastrophism.
Put another way, as we continue to search for advanced ETI's, and as we come to discover the absurdity of our isolation here on Earth, we may have no choice but to accept the hypothesis that advanced life does not venture out into space for whatever reason (the most likely being self-destruction).
Our other option is to cross our fingers and hope that something radical and completely unpredictable lies on the other side of the technological Singularity.
Friday, May 25, 2007
How will our Universe die?
An interesting theory has emerged which predicts that trillions of years into the future, the information that currently allows us to understand how the universe expands will have disappeared over the visible horizon. All that will remain will be "an island universe" made from the Milky Way and its nearby galactic Local Group neighbors. What's left will be a dark and lonely void.
The theory was put out by physicists Lawrence Krauss from Case Western Reserve University and Robert J. Scherrer from Vanderbilt University. Their research article, titled, "The Return of the Static Universe and the End of Cosmology," will be published in the October issue of the Journal of Relativity and Gravitation.
This brings to mind a number of different theories in the field of cosmological eschatology.
The Big Crunch
The work of Krauss and Scherrer stands in sharp contrast to another end-state theory, namely the Big Crunch. In this model, the momentum of the Big Ban will eventually wane causing the Universe to collapse in on itself. But due to the recent revelation that the Universe is not just expanding but that its expansion is speeding up, newer theories have suggested that the Universe will continue to expand forever.
The Big Rip
This has lead to some rather bizarre conclusions, including the emergence of a theory known as the Big Rip. According to this theory, the Universe will start to expand at such a rapid rate that all its elements, from galaxies to atoms, will be torn apart by the extreme expansion rate of the Universe. This is scheduled to happen about 20 billion years from now.
The force that is causing the Universe's matter to push outwards is what's known as dark energy. This is why galaxies are moving away from each other -- and why they will continue to do so until gravity will be too weak to hold them together.
Eventually, in the final months of the Universe, our solar system will be gravitationally unbound. In the last minutes, stars and planets will be torn apart. And in the Universe's final spastic salvo all atoms will be destroyed.
Heat Death
Another possibility is the Heat Death of the Universe, also known as The Big Freeze. In this model the Universe would continue to expand forever, but it would enter into a state of maximum entropy in which all matter and energy is evenly distributed; consequently, there would be no 'gradient' to the Universe -- a characteristic that is needed to sustain information processing, including life.
Other theories
Other possibilities include the False Vacuum, where the laws and constants of the Universe are subject to radical change, and various multiverse theories in which the cosmos is expressed in a infinite number of iterations for an infinity.
Another more radical possibility is that the future of the Universe will be influenced by intelligent life. Theories already exist in regards to stellar engineering -- where a local sun could be tweaked in such a way as to extend its lifespan. Future civilizations may eventually figure out how to re-engineer the Universe itself (such as re-working the constants) or create an escape hatch to basement universes.
Thinkers who have explored this possibility include Milan Cirkovic, John Smart, Ray Kurzweil, Alan Guth and James N. Gardner.
Read more here.
Saturday, January 27, 2007
Brian Swimme on Pierre Teilhard de Chardin
What is Enlightenment? + Zaadz has an extremely interesting interview with mathematical cosmologist Brian Swimme in which he discusses the influential Jesuit mystic, Pierre Teilhard de Chardin. Here's an excerpt from the article, Awakening to the Universe Story:
Teilhard also spoke in terms of “giving birth to person.” For example, your colleague Craig is there across the room. But if you go back five billion years, all of the atoms in Craig’s body were strung out over a hundred million miles. The process, as mysterious as it is, of matter itself forming into personality or personhood, is what Teilhard regarded as the essence of evolution. Evolution isn’t cold. He saw the omega point as that same process of giving birth to or actualizing this new, encompassing Divine Person—through not just all the atoms interacting with one another, but also the “persons” of all the humans and other animals. All of us together are part of this same process, so that the entire universe becomes God’s body. To really get how radical Teilhard’s view is, think about an animal and dissolve the animal back in time in your imagination, back into individual cells. There weren’t any multicellular organisms until about seven hundred million years ago. For over three billion years, there were just single-cell organisms. If you get to know an animal well, the animal really has a personality. But the personality is something that is evoked by the cells of the animal. It’s truly mysterious. The animal’s personality is real, but that personality is evoked by the cells. So in Teilhard’s view, the individual members of the universe are actually in a process of evoking a Divine Person. We are actually giving birth to a larger, more encompassing, mind-spirit-personality.
Friday, January 26, 2007
Latest podcast available
My latest audiocast has been posted here. You can subscribe to this feed.
In this episode I ask the question: when did intelligence first emerge in the Universe? I also discuss the stupidity of Star Trek's Prime Directive, bald women in science fiction, and mind-controlling parasites.
Thursday, January 18, 2007
Bjork's colonization simulation does not explain Fermi's Paradox
A number of science sites are proclaiming that the