The starting point of the anthropic principle (AP) - with distinguished authors such as Barrow, Tripler, Carr, Davies - is the so-called fine tuning: that the existence of our universe, and hence of our solar system and our life, is due to an extremely fortuitous combination of the numerical values of cosmological constants. So that, the argument goes, if only one of those constants would have been different by, say, one part in thousand, our universe would not have originated. Let me give at this point a quote by Stephen Hawking (cited by Shermer):
And why is the universe so close to the dividing line between collapsing again and expanding indefinitely? [...] If the rate of expansion one second after the Big Bang had been less by one part in 10 10, the universe would have collapsed after a few million years. If it had been greater by one part in 10 10, the universe would have been essentially empty after a few million years. In neither case would it have lasted long enough for life to develop. Thus, one either has to appeal to the anthropic principle or find some physical explanation of why the universe is the way it is.
And even cautious scientists like Freeman Dyson had to write back in 1985:
As we look out in the universe and identify the many accidents of physics and astronomy that have worked together to our benefit, it almost seems as if the Universe must in some sense have known that we were coming.
But at this point the very AP people asked themselves: how was it possible that such very improbable “fine tuning” came about? And here comes the pearl of AP, a very fascinating one: the multiverse. With the idea is that there is not only one universe - ours - but an infinite number of universes, each with its own natural laws and cosmological constants, and ours is just one of them, and we happened to be here, in the universe which happens to have those cosmological constants which have permitted the existence of our solar system in the way it is, and then life on Earth.
The particle physicist Susskind (2005), sees the “multiverse” – also called the “parallel universes”- as a huge number of “pocket universes” – and Paul Davies (2007) adds a touch of additional sophistication when he links the question of the constants of the universe to an even larger context - the connection with consciousness as a creative force in nature, as a teleological, immanent principle that makes life and consciousness appear as a necessary feature of the universe. Of course, there is no way to demonstrate scientifically the existence of other universes. This is however no particular obstacle to theoretician cosmologists, and extremely sophisticated papers and books about the multiverse continue to be currently published- occasionally linked to quantum mechanics, string theory, and/or relativity, or God himself - see the few references, or look into Google.
Now, let us abandon the cosmic dimension to go back to the terrain problem of the origin of life on Earth. And see whether we can construct an analogy with the multiverse. Let us begin by recalling that life on Earth is cellular, and only cellular- so that for the beginning of life on Earth we must look at the origin of the first cells. Experimental scientists of the origin of life of this camp, utilize vesicles or liposomes (vesicles formed by lipids) as models for cells, and introduce inside them biological components like nucleic acids and proteins, in order to possibly reconstitute the simplest possible biological cell. In figure 1, you see the schematized structure of a liposome, with the lipid bilayer typical of our cells, and one example of vesicle formed by synthetic surfactant molecules, in this case fatty acids.
The origin of life is still a mystery, but the generally accepted assumption is that life originated from the inanimate matter, through a series of spontaneous and partly accidental events which, starting from simple molecules, brought about an increase of molecular complexity and functionality, up to the point of a full-fledged cellular structure, that could display homeostasis (dynamic stability over time) and eventually self-reproduction.
We do not know how this happened - around 4 billion years ago; and one of the major conceptual and experimental difficulty, is the following: that all life on Earth is based on orderly sequences of macromolecules- proteins and nucleic acids, formed by hundreds or thousands of aligned monomers (amino acids or mononucleotides) - where “orderly sequences” means that the order of alignment of the monomer units is fixed, as shown in the example of figure 3. And we simply do not know how this sequential order came about under prebiotic conditions, but we have to start from the consideration that at some point it must have been there.
See my recent book (2016) for a more detailed discussion on the theories about the origin of life. One additional problem, even starting from an already formed mixture of DNA and protein sequences, is that one needs a relatively high internal concentration of these biopolymers to have a viable model of the cell. But how to achieve that, considering that the “prebiotic broth” could conceivably had been only a very diluted solution? Now, this problem of achieving a high internal concentration of biopolymers inside vesicles has recently found a solution-thanks to one serendipitous finding in the biophysics of liposomes. The finding is the following (Luisi et al, 2010): it is possible to have a spontaneous process of “overcrowding” even starting from a relatively dilute solution of biopolymers.
This is when vesicles are formed in situ in such a solution: the closing of the vesicles acts as an attractor, and some of them are sucking in most of the solute macromolecules, while most of the other remain empty. This is the “all-or-nothing” situation, and a typical electron microscopy experiment is shown in figure 2. Only a small percentage of the vesicles are then going to be overfilled. Consider however that, even if we have only 0.1% of over-filled vesicles in a diluted solution (say micro molar in lipids, which is approximately 10 -11 M in vesicles), given the value of the Avogadro’ number (6.02x10 23 ), we have billions of them in one litre solution.
In conclusion, then, from the initial diluted solution of DNA and polypeptides sequences we can go to the situation depicted in fig.2, in force of which we have a landscape of billions of overcrowded cellular structures which statistically differ in composition. And let us now focus on the question of the origin of life. And here comes also the analogy with the multiverse. The point is that, given such a large multitude of overcrowded cells, there is a good probability that one or a few are viable for life, which means homeostasis and eventually self-reproduction. In fact, these “good” cells may actually contain an excess of genetic material, so that, by fusion with neighboring “limping” cells, the latter can be transformed in good ones; a process which can then propagate exponentially eventually producing a large number of viable, living cells. This is represented schematically in figure 5.
In general, the analogy with the cosmic multiverse is the following: that instead of starting from a singularity, we start from a multitude of structure which have a statistical distribution of components; and that by chance, one or a few of these over-filled structures is viable for the beginning of life. Speculations? Yes. But nobody was there at the beginning of the universe or at the beginning of life, we have only speculations, and one of them must contain the truth.
D. Wallace, The Emergent Multiverse: Quantum Theory according to the Everett Interpretation, Oxford University Press, 2012.
K. Laughed, Faith and Philosophy, 32 (4)480-84, 2015.
P. Davies, Cosmic Jackpot, Houghton Miffin, 2007.
L. Susskind, The cosmic landscape: String theory and the illusion of the intelligent design, Little Brown, 2005.
K.J. Kraay, God and the multiverse: scientific, philosophical and theological perspectives, Routledge, 2015.
F. Capra and P.L. Luisi, The Systems view of life, a unifying vision, Cambridge Univ. Press, 2014.
P.L. Luisi, The emergence of Life, Cambridge Univ. Press, 2016.
Luisi, P. L.; Allegretti, M.; Souza, T.; Steineger, F.; Fahr, A.; Stano, P., Spontaneous protein crowding in liposomes: A new vista for the origin of cellular metabolism. ChemBiochem, 11, 1989-1992, 2010.