Epilogue Learning to Read the Book of Life: an Interdisciplinary Process
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_____________ Epilogue _____________ Learning to read the Book of Life: An interdisciplinary process The main message that we have attempted to transfer to our readers is that unlike most other branches of science, astrobiology is an interdisciplinary activity that crosses over the frontiers of science and the humanities. We have not intended to teach the readers how they can read the Book of Life, but rather how The Book of Life itself has began to be intelligible from the point of view of science since early in the 20th century. Although efforts to come to grips with the phenomenon of life have been part of human culture since Ancient Greece, in the Introduction we have shown that biology was not ready to lend us a hand, not even after the most significant and relevant scientific revolution that took place with the coming of Darwinism towards the middle of the 19th century. Darwin himself was of the opinion that time was not ripe for such an undertaking during his lifetime (cf., “Introduction”, p. 7). The emergence of the science of astrobiology was a gradual process, in which a stunning range of scientific disciplines took part. Some aspects of this vast scientific discipline are still to be fully comprehended. We would like to take a stroll with the readers along the pathway that we have followed together. In Chapters 1 and 2 astrophysics and cosmology, together with organic chemistry, showed us the way to the fundamental enquiry of how life has emerged in the cosmos. This was the main topic of what we have called the “First Part of the Book of Life” (cf., pp. 29-100). In these pages we have seen how Alexander Oparin, Stanley Miller, Joan Oro, Cyril Ponnamperuma, Sidney Fox brought to our attention the chemical evolution of the main ingredients of living microorganisms that later would evolve from bacteria to humans. But even though they may be considered pioneers of astrobiology, they were not working in isolation. We have attempted to show the reader that it was not just the card-carrying organic chemists the scientists that were creating the foundations of astrobiology. Geochronologists, such as Stephen Moorbath, together with geochemists, such as Manfred Schildowski and Gustaf Arrhenius, and micropaleontologists, such as J. William Schopf were making independent preliminary, but significant steps in the right direction. Already in Chapter 3 we discussed the early, as well as the current steps in planetary science, especially the “conquest of the Moon” that had caught for a brief period the imagination of the layman who was witnessing a race between two J. Chela-Flores, The Science of Astrobiology: A Personal View on Learning to Read the Book of Life, 281 Cellular Origin, Life in Extreme Habitats and Astrobiology 20, DOI 10.1007/978-94-007-1627-8, © Springer Science+Business Media B.V. 2011 282 THE SCIENCE OF ASTROBIOLOGY superpowers. Like Camelot it was an inspiring, but alas too brief a moment. We had to wait forty years—a biblical time—to return to the nearest body of the Solar System. A search for biomarkers has been initiated with the hope that they could orient us in the search for our own origin. We have to search for samples not just in the very limited area on the visible side of the Moon probed by the Apollo missions, but also in the polar region and on the far side of the Moon. There was an intense traffic of meteorites in the heavy bombardment period in the early Earth-Moon system. We cannot exclude a rapid onset of life even in that early period (the Early Archean around 4 billion years before the present). This implies that eventually even the Moon should be a target for astrobiology, in spite of the high costs of exploration. We also need to probe the small bodies of the Solar System, with Rosetta and other missions. In addition we should bring back samples from Mars with the Mars Sample-Return mission and get further insights from oceanography beyond the terrestrial limits to which astrobiology has been confined. In this context, glaciology in Antarctica and northern Canada can lend us a hand in these analogs of the surface of the icy satellites of Jupiter, as we have discussed in Chapter3. Beyond planetary science, in Chapters 5 to 6 we have completed a brief review of the “Second Part of the Book of Life” (cf., pp. 101-131). We have discussed how the other great revolution of last century—molecular biology—can orient us in putting biology solidly into astrobiology. We illustrate how the earth sciences atmospheric physics and climatology play a role in astrobiology. Similarly, we discuss the relevance of anthropology in Chapter 6. A significant challenge while reviewing the whole spectrum of astrobiology is the “Third Part of the Book of Life”. Not surprisingly it has taken the major part of the book (cf., pp. 133-214). A fleet of missions are currently either on Mars, or in their planning stages (Chapter 7). Spacecrafts and their probes have reached, or will reach the outer Solar System: Galileo, the Europa Jupiter System Mission and Cassini Huygens (cf., Chapters 8 and 9). Technologies such as the penetrators with their potential for transporting in-situ microlaboratories to the Solar System bodies can reach the Moon (not only the very limited area known to us since the Apollo era, but also the lunar poles and its far side). Subsequently, penetrators are in principle capable of probing the icy surfaces of the Jovian satellites (and beyond) in search of geophysical insights into the origin of the bodies of the Solar System and in search of reliable and unambiguous biomarkers. Since 1995 the discovery of Michel Mayor and colleagues of a large number of exoplanets in our galactic neighborhood adds hope that the search for biomarkers outside the Solar System will yield its fruits. The Kepler mission is widening surprisingly fast our repertoire of exoplanets beyond the early efforts of Jean Schneider and colleagues with CoROT (Chapter 10). This gigantic step forward in astronomy that is relevant for astrobiology has as a major consequence with which this part of the Book of Life ends. Indeed, for over half a century the search for extraterrestrial intelligence (SETI) has improved its technological capabilities well beyond all the expectations of its pioneer Frank Drake, when he first searched for intelligent signals with Project Ozma (Chapters 11 and 12). In the concluding “Fourth Part of the Book of Life” (cf., pp. 215-280) we bring into focus additional aspects that lie beyond the frontiers of science, mainly philosophy and theology (Chapters 13 and 14 and 16). These considerations allow us to reflect on the larger issues that affect astrobiology. We have questioned our eventual ability to complete all the objectives of astrobiology. Is the distribution of life in the universe a EPILOGUE 283 project that can eventually run into conceptual difficulties? To answer these questions we bring in Chapter 15 other scientific disciplines into the science of astrobiology, including especially the physical sciences at the atomic, nuclear and subnuclear level. These scales are presently available for experiments at the Large Hadron Collider. We return to the some of the preliminary mathematical insights that were followed up at the end of the 1950s. This approach led the physicist Stanley Mandelstam to change the course of subnuclear physics away from the quantum mechanics and quantum field theory that had begun in the 1920s with Werner Heisenberg, Paul Dirac and Erwin Schrodinger and other physicists (Chapter 15, Sec. 15.7). These early efforts of Mandelstam led to a group of physicists Tullio Regge, Gabriel Veneziano, Miguel Angel Virasoro and others to a theory that eventually was given its final form by several scientists, prominent amongst which was Edward Witten. We complete our discussion of astrobiology in Chapter 16 with philosophical reflections on the pathways that our current research in astrobiology is heading. We present the reader with alternative interpretations of modern cosmology that do not necessarily close the door for us to complete the program of astrobiology, especially obtaining eventually a complete understanding of the distribution of life in a cosmos. We present a point of view, still not of general agreement, in which there may not be an intrinsic difficulty in cosmological models that would be an impediment for our understanding of the distribution of life in an evolving cosmos. Having expressed the contents of the present volume in the last few pages, it may seem pretentious for a single author to have attempted a decade ago to cover the whole spectrum of this fascinating science in “The New Science of Astrobiology”, the first edition of this book. A decade later we have made a modest attempt to repeat the previous effort hoping to eliminate the many shortcomings of our earlier book, even though the author is aware that the previous criticism addressed to a single author may be brought upon him. In spite of his single authorship, he has not proceeded in isolation. He has been fortunate to benefit from the experience of some of the scientists that were mentioned in the previous chapters. This opportunity was granted to him firstly as a graduate student attending the International Center for Theoretical Physics (ICTP) at a time when Bethe, Crick, Dirac and Heisenberg converged in Trieste for the inauguration of the present premises of the ICTP (cf., Figs. I.10, 1.3, 15.3 and 15.2). The Nobel Laureate Abdus Salam had founded the ICTP in 1964. When the author completed his career at the Simon Bolivar University (Caracas) he returned to the ICTP.