CHAPTER 1: The Light of Photophysics and Photochemistry

Light, as a Divinity or as its manifestation,^1,2  has always been worshipped,³  and invoked as a theme of myths,⁴  hymns or poems,⁵  as in the wonderful verses of Thomas Stearns Eliot.⁶  Light was the basis of philosophical metaphysics⁷  and theologies.⁸  This can be understood from a rigorous philosophical phenomenology of light that is based only on human experience. Light has always been fundamental in human experience: sunlight as a source of vision and primary knowledge of things and as a source of heat and life; its absence was experienced as cold and death.

Light has been the subject of the scientific discipline of optics as a science of vision. And Euclid certainly used its propagation as a model of its geometry: if one can understand the birth of the concept of point by observing the stars as luminous points in the night on the celestial vault, one can also understand the origin of straight lines in terms of rays of light. And so, it can also be understood how the announcement, made by Arthur Stanley Eddington on 6 November 1919 to the Royal Society of London, of the observation of the curvature of light rays, led to the abandonment of Euclid's geometry and the theory of gravitation of Newton and the affirmation of Einstein's theory of general relativity with his pseudo-Riemannian four-dimensional chrono-geometry.⁹ 

And if a wave model of the propagation of light was already proposed in the seventeenth century by Christiaan Huygens,¹⁰  it was only with Maxwell's theory of electromagnetism¹¹  that he defined a physical theory of light, independent of a theory of vision.¹²  Visible light was identified with a particular range of electromagnetic waves, while vice versa one could speak of the complementary set of electromagnetic waves as invisible light. Light was understood as an electromagnetic field propagating in space and time. A new mathematics was needed to treat light as a wave phenomenon propagating in space and time: the theory of partial differential equations. And a few years later, in 1905, Henri Poincaré¹³  introduced four-dimensional space-time as a chrono-geometry¹⁴  necessary for the description of the electromagnetic field propagating in space and time, as it can never exist at rest as a material body whose positions can be described in terms of a three-dimensional geometry.¹⁵  Poincaré developed and completed the electromagnetic conception of Nature. After the predominance of a materialistic and mechanistic conception of physical reality that had imposed itself with Descartes and Newton,¹⁶  who despite having introduced the forces, attributed them to the governing action of God on Nature and not belonging to Nature itself (gravitational forces as actions instantaneous and at a distance could not be attributed to Nature as matter, but only to a divine spirit that dominated Nature-matter),¹⁷  Maxwell had introduced a dualism in the conception of Nature: Nature was no longer just matter, a set of material bodies, but it was also an electromagnetic field, visible and invisible light. The forces were real entities as Newton believed, and not mere mathematical constructs as thought by D'Alembert¹⁸  because the electromagnetic forces were not proportional to the accelerations and therefore could not be reduced to the name of the product of mass for the acceleration of a material body. However, the forces had to be understood as fields, that is, in the spatio-temporal finiteness of physical reality. Maxwell's equations admitted solutions even in the vacuum: the electromagnetic field existed even in the absence of matter. The flow of the electromagnetic field could explain the origin of the electric charge and Poincaré showed,¹⁹  before Einstein,²⁰  that the mass, the quantity of matter of a body, could be nothing but localized energy of the electromagnetic field. Poincaré then deduced that physical reality was only electromagnetic field, light and decreed the end of matter:²¹  this was the electromagnetic conception of Nature, a new unitary conception.²²  Matter derived from the electromagnetic field, from light, and so mechanics could only derive from the theory of electromagnetism: thus, Poincaré formulated the theory of relativistic dynamics as invariant under Lorentz transformations like electrodynamics. In 1912, Poincaré also first built a quantum theory of the electromagnetic field,²³  which then emerged as quantum electrodynamics or as a quantum-relativistic theory of the electromagnetic field, of light.²⁴  On the other hand, Heisenberg²⁵  had formulated his quantum mechanics starting from the operational epistemological assumption that we can know the atomic and subatomic world only on the basis of the processes of absorption and emission of the electromagnetic field and that therefore the only fundamental physical variables to be defined are the intensity and frequency of the electromagnetic waves involved.²⁶  Current quantum-relativistic unified field theories can indeed be interpreted as generalizations and extensions of the electromagnetic field, which includes within it the fields of weak and strong nuclear forces and finally also the gravitational field. The generalized light is thus the constitutive reality of the universe.

If it was immediately understood that living bodies had to be described as open thermodynamic systems that can increase their organization and complexity, decreasing their entropy at the expense of the entropy of the Sun radiating light,^27–29  it has not yet been underlined that the same origin of life^30–32  on Earth can be understood as linked to the growing organization of open terrestrial thermodynamic systems due to solar radiation:^33,34  the experimental and simulation inquiries of pre-biotic photochemistry could shed light on these processes. These thermodynamic processes, usually understood in terms of exchanges of entropy, for the relationship between negentropy and information³⁵  can also be interpreted in terms of exchanges of information that is conserved.³⁶  The religious mythopoetic understanding of the origin of life postulated an intervention by a celestial divinity: the current scientific understanding can present itself as a concretization of that intuition; life on Earth would not have originated if not for the action of the celestial light of the solar radiation, which produced a discontinuity like a quantum leap.

On the other hand, the negentropy-information relationship makes us understand that thermodynamic or physical processes cannot be understood only on the basis of purely mechanical or material variables but rather they are processes in which an immaterial variable such as information intervenes. There is therefore continuity and discontinuity between physical and biological processes. As in the revolution of molecular biology, which, by using the explanatory concept of information, reversed the hierarchical relationship between biology and chemistry that sought to base biology on chemistry, so in the same pre-biotic photo-chemistry a revolution of the same kind is implicitly announced: the information of intervening light is fundamental to understand also the pre-biotic chemical processes. All this can be understood more deeply if one takes into account that a conceptual understanding even of macroscopic processes, at the level of molecular agglomerates or cells, can only take place in terms of a fundamental physical theory of the quantum-relativistic field and quantum electrodynamics: the classical physical theories of macroscopic processes can be mathematically approximate, or almost exact in all practical effects, but cannot provide the conceptual framework of the understanding of reality that can only be given by the quantum-relativistic theory of fundamental field. One has to realize a quantum-relativistic bio-electrodynamics, where living beings are the realization of a new phase of the theory characterized by semi-autonomy and informed freedom, and experimental and simulation pre-biotic photochemistry could inquire the establishment of the conditions of the related phase transition.

We must therefore free ourselves completely from the mechanistic conception of Nature and introduce a global dynamic information variable as necessary: information,^37–39  equivalent to a thermodynamics negentropy and linked to the quantum probability expressed by the so-called “wave functions” or from the “density matrices” or from the fields characterizing the “quantum state” of a physical system.^40–42  Quantum information is total or global information and requires a new characterization with respect to previous mathematizations,^43,44  also to take into account its non-additive property characteristic of complexity.⁴⁵  Each subsystem of the universe is information and can be expressed individually only through the incomplete information of the density matrices that express the inseparable (entangled) correlation with the rest of the universe:⁴⁶  the second law of thermodynamics becomes for the universe a “law” of conservation of the entropy and therefore of information, which, relativistically and quantistically, also becomes a “law” of non-mechanical, non-causal and non-random correlation of information of every part and of the rest of the universe and, if infinite, also a “law of epigenetic creation” of new forms that are not pre-established or idealistically pre-formed.

Life on Earth depends on the Sun not only for an exchange, a “gift” of light and energy, heat, by the Sun, but also of negentropy-information: the Sun is not mere massive matter, but also information and a source of information, that means that understanding the solar system from a dynamic point of view must also take into account the global information that coordinates it; it is the light that as a field, that correlates and coordinates and as global information, constituted the origin of life on Earth and allowed its evolution as an internal and external factor.

For quantum bio-electrodynamics, life does not appear at all reducible to its inert and passive material constitution and traditional chemistry must be changed into a quantum photochemistry: photochemistry is not to be considered only a particular sub-discipline of chemistry, but a revolutionary way to understand reality for the relevance given to (quantum) light fields as guides of formation of life. Life constitutive units appear to be regulated by exchanges of quantum (immaterial) electromagnetic fields (light), which alone can explain the coherence of biological structures and the molecular coordination of cells and in particular nerve cells within active global information and the properties of consciousness: life and intelligence are a phenomenon of “super-radiance” of light^47–50  and evolution has mainly depended on the ability to absorb electromagnetic bio-information from sunlight.^51–55  Living bodies are not mere material structures, but also and above all fields of light (quantum electromagnetic fields of light are not purely local, but are global information fields and can also constitute those “morphogenetic fields”^56,57  invoked by various dissident biologists with respect to Darwinism; quantum electromagnetic fields are “local” only from the point of view of material observers, but all the events of the universe, as Whitehead⁵⁸  had understood, are globally connected to each other by light in a null spatial and temporal interval); if life is light, then a quantum biology^59–62  of light and a quantum biophysics^63–66  of light constituting the activities of living beings must be developed.^67–69 

On the other hand, on a larger scale, the quantum cosmological evolution of the universe, guided by a “wave function” or by a density matrix or by a quantum-relativistic field of generalized light of the universe, is in effect governed by a global information function: light is living intelligence. It is not a casual or causal and mechanical emergency that of life on Earth or in the cosmos; everything is an explanation of an implicit global order (in the deterministic interpretation of Bohm's quantum mechanics, information is an intangible active principle, not reducible to a local mechanical cause, as information acts as a sort of “quantum potential” which does not decrease with distance),⁷⁰  but is indeterministic.⁷¹  Everything is somehow included in the infinite quantum-relativistic vacuum,^72–74  in the zero point field of light as the “field of creation”,^75–77  but there are specific, emerging fields of light that create and coordinate the various subsystems of the universe and the various levels.^78–81  As the cosmologist Paul Davies⁸²  explains at an already popular level, the ultimate origin of genetic-cellular-epigenetic information is linked to the expansion of the universe, of the space-time constituted by light, to a cosmic dynamics governed by global information of the universe.