Some scientists believe that six numbers are evidence that are universe anticipated the eventual emergence of intelligent life. Science, remember, advances by looking for patterns and regularities in nature. These allow more and more phenomena to be placed in general categories. The overall aim is to encapsulate those general catagories (ie physical laws) in a unified set of equations.
Each one of those six numbers, then, describes some aspect of physical reality. One number is a measure of the strength of the electrical forces that hold atoms together, divided by the force of gravity between them. The second number defines how firmly atomic nuclei bound together, and so determines a star’s ability to transmute hydrogen into all the other atoms. The third number measures the relative importance of gravity and expansion energy in the universe. The fourth number controls a mysterious anti-gravity force that is believed to be slowly but increasingly accelerating the expansion of space (not to be confused with inflation, which was something else entirely). The fifth number relates to the primordial ripples in the fabric of spacetime, and the sixth number refers to how many large spatial dimensions there are.
What is so significant about these numbers is that they cannot be any old value, not if you want a universe in which DNA-based life can evolve. Change the value of any one of those numbers and you alter some aspect of physical reality. More often than not, the alternate reality produced when ’fiddling with the settings’ is incapable of supporting life-as-we-know-it. Take the second number, the one that controls nuclear fusion in stars. The value of this number is 0.007. If it were 0.006, it would be impossible for a proton to bind to a neutron, making deuterium unstable. That, in turn, would have made chemistry impossible and so DNA-based life could never have evolved. If the number had been 0.008, two protons would have been able to bind directly together, which would have had an effect on the life cycle of stars that would have ruled out the possibility of there being water in the universe. So, again, there would be no life-as-we-know-it. Or take the number that controls the relative importance of gravity and expansion energy in the universe. Cosmologists call this number Omega and its value is 1.0. A deviation of anything more than one part in a million billion would be disastrous from our perspective, because the result would either be a universe that collapses before galaxies have any chance of forming, or the universe would expand too quickly for galaxies to form. So, the physical laws need to be fine-tuned or else life-as-we-know-it cannot evolve. On contemplating this fact, the physicist Freeman Dyson commented that it seems ’the universe knew that we were coming’.
What great destiny does the universe have for the life it seems to have been fine-tuned to create? According to the vast majority of cosmologists, the long-term prospects for life is grim indeed. In 1854, the German physicist Hermann von Helmholst realized that the laws of thermodynamics could be applied to the universe as a whole. The Second Law of Thermodynamics tells us that the total amount of entropy (disorder) must increase. Applied to the universe as a whole, it means that all useful forms of energy will, in time, be transformed into disordered energy. Fred Adams and Greg Laughlin of the University of Michigan divided the age of the universe into 5 distinct states:
The primordial era: Starts at the inflation period and ends with the creation of hydrogen and helium.
The Stelliferous era: The hydrogen gas collapses under its own gravity and nuclear fusion begins. Stars blaze away and conditions are ideal for DNA-based life.
The degenerate era: The stars burn through their reserves of nuclear fuel and, once it is exhausted, they are extinguished.
The black hole era: The only energy now comes from the radiation that black holes are believed to emit. Leaking this so-called Hawking radiation causes black holes to evaporate. The more massive a black hole is, the longer it takes to evaporate. The most massive black holes are thought to leak radiation for about 10^117 years before finally evaporating.
The dark era: All useful energy in the cosmos is utterly spent. The universe is dead.
As you can probably guess, right now we are in the Stelliferous era when conditions are optimal for our kind of life. When judged on human timescales, the time it will take for this period to end (and the amount of time that has passed since it began) seems truly immense. But from the perspective of cosmological timescales, the Stelliferous era exists for only a brief period of time. Life, it seems, is a fragile and transitory phenomena that is doomed to quickly perish.
Or is it? In 1979, Freeman Dyson studied the thermodynamics of life and came to believe it could exist indefinitely. Not human life, mind you, or any kind of biological life at all. Rather, Dyson generalized life in terms of information processing and then asked how long information processing could continue as the universe’s energy ran down. Information theory tells us that the smallest unit that can be sent is proportional to the temperature. This means that, as the temperature of the universe falls, the bits of information that can be sent have to be smaller and smaller. Dyson reasoned that his hypothetical software-based life would have to think at slower and slower rates as the temperature of the cosmos continues to fall. Dyson realised that slowing down the rate of thinking would not be enough to keep going indefinitely. Quantum mechanics dictates a fundamental limit to how fast heat can be dissipated. An organism that produces heat faster than its electrons can dissipate it will die from overheating. So Dyson concluded that there would have to be periods when life hibernates – goes ’offline’, essentially – in order to avoid overheating. Those periods of utter inactivity would have to grow increasingly long as the temperature of space fell. Life might have to wait trillions of years in order to process a single thought.
Ironic, really. Ask any inhabitant of online worlds what is most annoying to them, and it is a fair bet that ‘slowdown’ and ‘lag’ would be high on most people’s lists. And trying to log on, only to find your online world has been taken offline is really terrible. But, according to Freeman Dyson, these great annoyances will turn out to be the last great hope for long-term survival! Recently, though, science has come to realize that Dyson’s strategy is ultimately doomed to fail. The plan relied on the 2.7 degree microwave radiation that fills all of space dropping indefinitely, providing tiny temperature differences from which useful work could be extracted. But, during the 90s, cosmologists found evidence of a mysterious force that is slowly causing the expansion of Space to accelerate. Not much is known about this ‘dark energy’, apart from the fact that it seems to be a property of ‘empty’ space (in quantum physics, terms like ‘empty’ mean something different to everyday concepts). The force of dark energy is proportional to the volume of the universe. The larger the universe becomes, the more dark energy there is to push galaxies apart, which in turn increases the volume of the universe. Eventually, dark energy becomes so strong that a horizon is formed (known as the Desitter Horizon), marking the point where dark energy has become strong enough to cause objects to recede at the speed of light.
In quantum physics, ‘empty’ space is seen as fluctuations in which pairs of particles and antiparticles are created before finding each other and cancelling each other out. But if one half of the pair crosses the DeSitter Horizon, the other half is left, contributing to the heat energy in the universe on our side of the horizon. This means that the temperature of space will not continue to fall indefinitely, but instead will reach a uniform temperature of 10^-29K. Now, people think it is cold when conditions are chilly enough for water to freeze, but on the Kelvin scale the freezing point of water is 273K. Clearly, then, a temperature of 0.000000000000000000000000000001K redefines the meaning of the word ‘chilly’. However, the ultimate fate of Dyson’s software-based life forms is not to freeze, but to burn. When, at last, we arrive at the Dark era, everything will be at the same temperature. Dyson’s information-based life forms will be unable to dissipate heat and so the instant any information processing is attempted, they will fry to death.
It would appear, then, that the immersionists’ dreams of attaining immortality by uploading into cyberspace and living forever as software-based life is ultimately doomed to failure. All forms of information-processing are destined to burn out in roughly 10^117 years’ time. But is this really the end? Is life’s struggle for survival and quest for knowledge really destined to simply burn out in the final state of high entropy 10^117 years from now, or could there be some way to preserve a record of our existence? According to a paper by J. Garriga, V.F Mukhanov, K.D Olum and A. Vilenkin (‘Eternal Inflation, Black Holes and the Future of Civilizations’) once dark energy becomes strong enough to dominate our Universe, bubbles of inflationary phase will begin to nucleate at a constant rate. According to some theories, inflation never completely ends. It is driven by something called the ‘Inflaton Field’ (no, that’s not a misspelling. Physicists often give fields names that end with ‘on’. Think Photon and Gluon). Quantum fluctuations allows for the possibility that the inflaton field will jump to the inflationary range, and since quantum fluctuations are different at different points in space, it follows that quantum tunnelling events in which the inflaton field jumps into the inflationary range cannot ocurr homogenously in space. The inflationary phase occurs in a spherical volume of space and the authors suggest that it could be possible, in principle, to arrange for information to be swallowed up by one of these bubbles and carried over to the termalized region (another universe, essentially) that would form once the false vacuum decayed.
As you can well imagine, there are a few technical difficulties to overcome before such a plan can succeed. One of the largest difficulties would be getting the information into one of these bubbles in the first place. This is because black holes are believed to form at a far more prevalent rate, putting the chances of the message being swallowed by an inflationary bubble (as opposed to simply being destroyed inside a black hole) at 10^122-1. This may sound like a completely hopeless cause, but we can at least appeal to our current lack of knowledge regarding the nature of black holes and speculate that there may be ways around this problem. Currently, we can only solve the equations for a single star in an empty Universe. But calculating the curvature of Space at any point requires knowing the location of all objects in the Universe, each of which contributes to the bending of Space. Such a calculation is currently beyond our capability (even taking our computers into consideration), so we can speculate about scenarios in which the plan has a greater chance of success and worry about it being ruled out later.
One such possibility is that black holes do not form a ‘singularity’ where spacetime comes to an end (the result you get using the standard theoretical model, based on a particular solution of Einstein’s equations that Karl Schwarzchild discovered in 1917). It could be that the Schwarzchild Solution needs to be replaced with a deSitter space with limiting curvature. If that were so, inflating Universes would automatically form inside black holes.
Assuming black holes are simply passages to a new inflating region, what other problems lie in store? There is a limit to the amount of information that can be sent through a black hole. The entropy of the package needs to be less than the entropy of the black hole, with the maximum amount of information being somewhere in the range of 10^13 to 10^68 bits. Physicist Michio Kaku has estimated that a post human civilisation would be seeking to send 10^24 bits (‘sufficient to recreate the civilisation’, or so he says) which would be clearly ruled out if the maximum amount of information that could be sent was in the lowest range (in fact, that would also rule out preserving all human knowledge, since the Library of Congress represents 10^15 bits). Being in the right place at the right time could also be a problem. Quantum events like the spontaneous creation of bubble Universes happen so rarely that one can rule out the possibility of witnessing such an event. However, we need to remember that Dyson’s software-based life forms would have a different perception of time to us. Recall that their environment would require them to think extremely slowly, perhaps taking a trillion years to process a single thought. From a subjective point of view their rate of thinking may appear to be perfectly normal, when objectively so much time has passed from one subjective awareness of a moment to the next that rare quantum events appear to happen quite regularly.
Another possibility is that future civilizations might purposefully trigger the nucleation of a bubble Universe. Alan Guth speculated, ‘since the inflationary theory implies that the entire observed Universe can evolve from a tiny speck, it is hard to stop oneself from asking whether a Universe can in principle be created in the laboratory?’. When asked to explain the reason for SETI’s failure to find evidence of intelligent life, a popular response is to say that such beings are not interested in establishing contact with us. This line of reasoning supposes that SETI is looking for alien communications, when in actual fact the search is for characteristic forms of radiation. In the 1960s, a Russian physicist called Nikolai Kardashev catagorized civilizations according to their ability to harness available energy. He then showed that their presence could be inferred from the waste heat generated by their activities. Today this is known as the ‘Kardashev Scale‘. It begins with Type I, defined as a global civilization able to harness all of the solar radiation striking the planet (roughly 10^16 watts). Next we have Type II, defined as an interplanetary civilization able to harness the total output of their local star. The energy they can harness exceeds that available to a Type I civilization by a factor of 10 billion- 10^26 watts. Then there is Type III, a civilization that has spread throughout and can harness the power contained in a galaxy. Again, they differ from the next lower type by a factor of 10 billion. Type III civilizations can harness 10^36 watts.
Obviously we Earthlings don’t yet have the ability to harness all of the solar energy striking our planet, so we don’t even qualify as Type I. However, Michio Kaku has said that certain developments may be an indication of us either being on the threshold of transcending to Type I status, or due for a catastrophe (at this point in time it’s hard to say how things will turn out). Kaku points out that ‘pollution will be increasingly tackled on a global scale’ and ‘as resources gradually flatten out due to over cultivation and over consumption, there will be increased pressure to manage our resources on a global scale’. Recall also the question I posed in ‘Metaverse: Reloaded’, ‘if operating systems and email eventually converged on a common standard, can we expect coalescence amongst online worlds?’ Again, one can single out such convergences as evidence that the World Wide Web is maturing as a global communication system, or one could argue that cases like Google censoring itself to appease authorities in Beijing is proof that we are as far from being One World as we ever were. Having said that, Kaku argues that transition to Type I status does not necessitate the eradication of nation states, only that ‘as business itself becomes more international, national borders become less relevant’.
Doom and gloom types might want to link the rising problems we face with the apparent lack of Type I-III civilizations elsewhere in the Universe. Perhaps civilization is doomed to collapse before the transition to Type I can be made? Here, though, we shall be optimistic and assume that the transition to Type I and thereafter to Type II and III is achieved. Suppose a technologically-advanced civilization wanted to build a machine capable of creating conditions necessary to trigger inflation. What kind of machine would the job require?
One such machine might be a particle accelerator, a descendent of scientific instruments such as the Large Hadron Collider. However, no Earthly particle accelerator is anywhere close to being able to generate the tremendous energies and temperatures triggering inflation requires. Such a task calls for a particle accelerator that is 10 lightyears long (by comparison, LHC is a pathetic 27 Km long). An engineering project of that magnitude is hard to conceive, admittedly, but it might be achievable to a civilization that has self-replicating robotic factories at its disposal. Another engineering project for Type II civilisations to consider might involve reworking the matter resources of a solar system into a huge sphere of converging lazers- powered by the entire energy output of the parent star, no less- that fire on a central point. Either way, the aim is to heat up a tiny region of space to 10^26 degrees K and then rapidly cool it down. It is conjectured that at this temperature, spacetime becomes unstable and a false vacuum is created. The engineers would not see the baby Universe being formed, as the process would take place inside of the event horizon of a black hole. In this scenario, the black hole is assumed to be a wormhole connecting our Universe to the new inflationary phase forming from the false vacuum. The black hole would evaporate, the ‘umbilical cord’ would be cut and the newborn Universe would go on to evolve through 10^117 years before maximum entropy is established in its region.
If the engineers responsible for creating the new Universe wanted to leave some kind of message for future intelligences to find, where might they put it? Ideally, the message would be readable from any location in the new Universe, and it would remain unchanged for however long it took for an intelligence able to read it to evolve. According to physicists Stephan Hsu of the University of Oregan and Anthony Zee of the University of California, the only thing that satisfies both conditions is the Cosmic Microwave Background. Imprinting a message onto the CMB would require a fine-tuning of the inflation dynamics, thereby imprinting indelible marks on the tiny undulations in the fabric of space thought to be generated during the first split seconds of a Universe’s birth. After that first split second, the false vacuum would drive regions of the Universe so far apart that light could not travel between them, and so no conceivable process could tamper with the message.
So, a Type II civilization creates a black hole, inside which a new inflating region (a ‘baby Universe’) is formed. After about 10^-35 seconds the false vaccum would decay and its tremendous energy would be converted into matter and heat. How would any civilizations evolving in this Universe decode the message from its creators? After about 13.7 billion years, the temperature of the CMB will have cooled to 2.7 degrees K. However, it would not be exactly that temperature all over the Universe, but instead would vary slightly from place to place. Hotter and colder spots are formed because of the primordial ripples in the fabric of space that are generated in the first instants of creation. These hot and cold spots give ‘temperature maps’ of the CMB such as those created by COBE and WMAP their distinctive blotchy appearance. Astronomers separate out the blotches into ‘multipoles’ and each multipole has a maximum temperature difference associated with it that corresponds to the difference between the hottest and coldest region. The temperature difference between each multipole is known as the ‘amplitude’. ‘It is these amplitudes that we believe are ideal places for the creator of the Universe to lodge a message to the Universe’s occupants’, claim Hsu and Zee. Decoding the message would therefore entail obtaining very detailed maps of the CMB.
What would the message say? It could be instructions on how, exactly, one goes about engineering a new Universe. If such a message were indeed found imprinted on the CMB, that would settle the question of how those six numbers came to be so fine-tuned. It was either deliberately designed by superior but comprehensible beings, or else it inherited the conditions of the Universe in which the builders lived. Of course, one does not need to posit the existence of Type II civilisations in a parallel Universe in order to explain the fine-tuning of the constants of nature. One could say that there are variations to these constants in each universe that forms in the eternal ocean of the false vacuum. Lifeforms would not evolve in universes whose laws were incompatible with life. The downside of this scenario is that it seems to demand a multiverse dominated by lifeless Universes. ‘To me, this is waste on a truly cosmic scale’, said Ed Harrison, one of the few thinkers willing to entertain the possibility that ‘life-bearing Universes come to dominate because intelligent life actively makes new Universes’.