Ecology: The Biology of Interaction. II-17. (Supplement) The Anthropic Paradox
By analogy with these formulations, one may propose a "very strong anthropic principle," one possible variant of which is the participatory anthropic principle: "The existence of the Universe, of humanity, and of each individual human being are interrelated parts of a single process." At the present stage...
II-17. (Supplement) The Anthropic Paradox
When you stand alone on an empty plateau beneath
the bottomless vault of Asia, where into the blue firmament
a pilot or angel rarely adds his starch,
and you involuntarily shudder, feeling your own smallness,
know that the space, which seems to need nothing more,
in fact so needs another
glance from outside, an appraisal, a criterion of emptiness.
And only you alone are capable of these unconditional things.
Joseph Brodsky. "Admonition" (1987). Translated by Larysa Vyrovets
In studying the peculiarities of humanity's relationship with its environment, we take our own existence as an accomplished fact. Could it have been otherwise? Yet according to contemporary views, the existence of humanity — and of life on Earth in general — is the result of a confluence of a whole series of favourable conditions. These include:
— the large mass of the Earth, sufficient to retain a powerful atmospheric layer, yet not so large as to cause that atmosphere to thicken, as on the giant planets;
— a powerful magnetic field that deflects high-energy cosmic particles;
— the presence of large quantities of water in three different states of matter, which stabilises the climate;
— an optimally configured orbit (if it were 5% smaller or 1% larger, life would be impossible);
— an active lithosphere, which drives the biogeochemical cycles;
— the presence of an exceptionally large satellite — the Moon — which provides tides, and so forth.
The ratio of the diameters of the Earth and the Moon is 4:1, whereas Jupiter's diameter exceeds that of Callisto by a factor of 20, Saturn exceeds Titan by a factor of 30, and Mars exceeds Phobos and Deimos by factors of 200 and 400, respectively. In all likelihood, the Moon was ejected from the Earth as a result of what is known as the Giant Impact. It transpires that for such an impact to tear a fragment of substantial size from the Earth, the impacting body must have had strictly specific parameters and struck at a particular, precise angle.
A remarkable feature of the Sun–Earth–Moon system is that, when viewed from the Earth's surface, the Sun and the Moon appear to be celestial bodies of identical size. This is a consequence of a coincidental (or is it truly "coincidental"?) correspondence between their actual dimensions and their distances from our planet.
The functions of the Moon include: providing tides, thereby creating intertidal zones that were essential for the transition of life onto land. The tidal pull of the Moon slowed the Earth's rotation from 4 to 24 hours per day, with the surface slowing more than the molten metallic core. This resulted in the Earth possessing a powerful magnetic field that shields living organisms from cosmic rays. Turbulent processes in the core cause periodic reversals of the magnetic field by 180°, which evidently played a significant role in the transformation and development of the biota (and, ultimately, in the emergence of humanity).
Finally, it must be noted that a necessary condition for our emergence is a vast prehistory. Successive generations of stars had to cycle so that the material from which the Solar System formed could attain sufficient elemental diversity. An immense history of the biosphere had to elapse for our species to arise within it. A magnificent history of the development of human culture had to unfold in order to shape our capacity for reflecting on cosmological problems.
In addition, one must acknowledge the enormous number of remarkable coincidences that can be identified in the ratios of the fundamental physical constants characterising our Universe.
In a whole series of cosmic constant values, the number 1×10⁴⁰ appears with surprising frequency. For example, by this factor is gravitational force smaller than electromagnetic force; by this factor does Hubble time exceed Compton time, and Compton time exceed Planck time. Approximately this many protons exist within the Hubble volume (the observable part of the Universe), and the total number of particles in a typical star is approximately this number raised to the power of 3/2. It is significant that alterations to these characteristics could lead to substantial changes in the Universe. Were the gravitational constant slightly larger, the Universe would collapse; were it slightly smaller, it would fly apart. Were the number of protons not 10⁸⁰ but, for instance, 10⁸⁶, the Universe would face collapse, and 10⁷⁷ would preclude the formation of galaxies. The ratio of the number of protons to the number of electrons — approximately 10⁹ (this quantity may also serve as a measure of the entropy of the Universe) — is a fortunate one, since the existence of the Universe is possible only within a range of values from 10³ to 10¹¹. The constraints are even more stringent: small changes in the entropy of the Universe would affect the prevailing ratio of hydrogen to helium nuclei (and all other nuclei), which would prevent the formation of complex systems composed of heterogeneous atoms. The observed ratio of protons to electrons is the result of the ratio between matter and antimatter at the moment of the Universe's formation (electrons are regarded as traces of the annihilation of protons and antiprotons). The formation of matter and antimatter was not symmetric: matter was produced in excess by one part in a million, and the magnitude of this excess was most felicitously suited to the creation of a world with the observed properties. The ratios of the numbers and masses of neutrinos are admirably arranged; it is important that the difference between the masses of the proton and the neutron is close to the mass of the electron. The favourable ratio of protons to neutrons is regarded as a result of "the magic of numbers" in the ratios of the principal physical constants: the Boltzmann constant, the speed of light, etc. (Following P. Davies, 1985).
The probability of the random coincidence of all these cosmological parameters — which together have ensured the existence of space-time, matter, atoms, galaxies, and stars — is, according to current understanding, entirely negligible (and many of the correspondences discussed here have not even been named). Apparently, there are factors not accounted for in standard cosmogonic models. Will not these factors also manifest themselves in the future, in some way influencing the potential habitability of the Earth for humanity?
The paradoxes set forth above led to the formulation of what is known as the anthropic paradox (also referred to as the anthropic principle or the anthropological principle). This principle has a sufficiently long history. It was first formulated in 1955 by the Kazakhstani astronomer Grigory Idlis and the Russian physicist Abram Zelmanov. The idea gained wide currency after it was advanced in 1973 by the English physicist Brandon Carter. Carter proposed the anthropic principle in two forms: "strong" and "weak."
The "strong" formulation: "The properties of the Universe are such as they must be in order to permit the existence of humanity." An alternative version: "Here is humanity. What must the Universe be like?"
The "weak" formulations: "What we are able to observe is limited by the conditions necessary for our existence as observers." "We witness processes of a certain type because other processes proceed without witnesses." This approach rests on the implicit assumption that other universes exist in which there are no observers. Does the assumption of the existence of other universes resolve the paradoxical character of the being of our Universe?
A special variant of the "strong" formulation is the participatory anthropic principle, formulated in 1983 by the American physicist John Wheeler: "Observers are necessary to bring the Universe into being." Quantum indeterminacy entails that different variants of the development of events may be simultaneously realised, and only through interaction with an observer does one of these variants become actualized, acquiring being (as, for example, in the well-known phenomenon of "Schrödinger's cat": a cat that will die as a result of one outcome of a quantum event and survive as a result of another may be simultaneously both dead and alive, until an observer "registers" one of these states).
By analogy with these formulations, one may propose a "very strong anthropic principle," one possible variant of which is the participatory anthropic principle: "The existence of the Universe, of humanity, and of each individual human being are interrelated parts of a single process." At the present stage it is impossible to prove this assertion. It by no means presupposes (though it does not exclude) an appeal to God. At the very least, it reflects the intimate connection between one's own being and the possibility of knowing the Universe — a connection reflected in the psyche of every human being ("Cogito, ergo sum," "I think, therefore I am" — René Descartes). The paradoxical nature of the proposed "very strong" formulation is no greater than the paradoxical nature of our own existence.