arXiv subjects

Milan M. Cirkovic

Publications and source records attributed to Milan M. Cirkovic.

At least 37 records · Page 2Linked to original sources

arXiv2003

Cosmic Irony: SETI Optimism from Catastrophes?

Classical arguments for skepticism regarding the Search for ExtraTerrestrial Intelligence (SETI) are critically examined. It is suggested that the emerging class of "phase transition" astrobiological models can simultaneously account for all available astrophysical and biological evidence, explain several unresolved puzzle in Earth sciences, and rationally justify current and future SETI projects. In particular, the hypothesis of Annis that local gamma-ray bursts drive the astrobiological phase transition deserves to be further quantitatively elucidated. Some epistemological and ethical ramifications of such a model are briefly discussed.

astro-ph↗

arXiv2003

A Comment on Tectonics and the Future of Life on Terrestrial Planets

It is argued that the tight interconnection between biological, climatological, and geophysical factors in the history of the terrestrial biosphere can teach us something of wider importance regarding the general astrobiological evolution of planets in the Galactic habitable zone of the Milky Way. Motivated by a recent debate on the future of Earth's biosphere, we suggest an additional reason why the impact of plate tectonics on the biological evolution is significant on the global Galactic level.

astro-ph↗

arXiv2003

Geo-engineering Gone Awry: A New Partial Solution of Fermi's Paradox

Another partial solution of Fermi's famous paradox is proposed, based on our increased understanding of geophysics, geo-engineering and climatology. It has been claimed in the recent astrobiological literature (for instance, in the recent controversial "rare Earth" theory of Ward and Brownlee), that geological activity of a terrestrial planet is an important precondition for the emergence of complex metazoan life forms. Technological civilizations arising on such planets will be, at some point of their histories or another, tempted to embark upon massive geo-engineering projects. If, for some reasons only very recently understood, large-scale geo-engineering is in fact much more dangerous than previously thought, the scenario in which at least some of the extraterrestrial civilizations in the Milky Way self-destruct in this manner gains plausibility. In addition, we speculate on possible reasons, both physical and culturological, which could make such a threat even more pertinent on an average Galactic terrestrial planet than on Earth.

physics.geo-ph↗

arXiv2003

Ancient Origins of a Modern Anthropic Cosmological Argument

Ancient origins of a modern anthropic argument against cosmologies involving infinite series of past events are considered. It is shown that this argument - which in modern times has been put forward by distinguished cosmologists like Paul C. W. Davies and Frank J. Tipler - originates in pre-Socratic times and is implicitly present in the cyclical cosmology of Empedocles. There are traces of the same line of reasoning throughout the ancient history of ideas, and the case of a provocative statement of Thucydides is briefly analyzed. Moreover, the anthropic argument has been fully formulated in the epic of Lucretius, confirming it as the summit of ancient cosmology. This is not only of historical significance but presents an important topic for the philosophy of cosmology provided some of the contemporary inflationary models, particularly Linde's chaotic inflation, turn out to be correct.

astro-ph↗

arXiv2003

On the First Anthropic Argument in Astrobiology

We consider the little-known anthropic argument of Fontenelle dealing with the nature of cometary orbits, given a year before the publication of Newton's Principia. This is particularly interesting in view of the rapid development of the recently resurgent theories of cometary catastrophism and their role in the modern astrobiological debates, for instance in the "rare Earth" hypothesis of Ward and Brownlee.

astro-ph↗

arXiv2003

The Temporal Aspect of the Drake Equation and SETI

We critically investigate some evolutionary aspects of the famous Drake equation, which is usually presented as the central guide for the research on extraterrestrial intelligence. It is shown that the Drake equation tacitly relies on unverifiable and possibly false assumptions on both the physico-chemical history of our Galaxy and the properties of advanced intelligent communities. The importance of recent results of Lineweaver on chemical build-up of inhabitable planets for SETI is emphasized. Two important evolutionary effects are briefly discussed and the resolution of the difficulties within the context of the phase-transition astrobiological models sketched.

astro-ph↗

arXiv2002

The Thermodynamical Arrow of Time: Reinterpreting the Boltzmann-Schuetz Argument

The recent surge of interest in the origin of the temporal asymmetry of thermodynamical systems (including the accessible part of the universe itself) put forward two possible explanatory approaches to this age-old problem. Hereby we show that there is a third possible alternative, based on the generalization of the classical ("Boltzmann-Schuetz") anthropic fluctuation picture of the origin of the perceived entropy gradient. This alternative (which we dub the Acausal-Anthropic approach) is based on accepting Boltzmann's statistical measure at its face value, and accomodating it within the quantum cosmological concept of the multiverse. We argue that conventional objections raised against the Boltzmann-Schuetz view are less forceful and serious than it is usually assumed. A fortiori, they are incapable of rendering the generalized theory untenable. On the contrary, this analysis highlights some of the other advantages of the multiverse approach to the thermodynamical arrow of time.

astro-ph↗

arXiv2002

On a Possible Physical Metatheory of Consciousness

We show that the modern quantum mechanics, and particularly the theory of decoherence, allows formulating a sort of a physical metatheory of consciousness. Particularly, the analysis of the necessary conditions for the occurrence of decoherence, along with the hypothesis that consciousness bears (more-or-less) well definable physical origin, leads to a wider physical picture naturally involving consciousness. This can be considered as a sort of a psycho-physical parallelism, but on very wide scales bearing some cosmological relevance.

quant-ph↗

arXiv2002

Quantum Parallelism in Quantum Information Processing

We investigate distinguishability (measured by fidelity) of the initial and the final state of a qubit, which is an object of the so-called nonideal quantum measurement of the first kind. We show that the fidelity of a nonideal measurement can be greater than the fidelity of the corresponding ideal measurement. This result is somewhat counterintuitive, and can be traced back to the quantum parallelism in quantum operations, in analogy with the quantum parallelism manifested in the quantum computing theory. In particular, while the quantum parallelism in quantum computing underlies efficient quantum algorithms, the quantum parallelism in quantum information theory underlies this, classically unexpected, increase of the fidelity.

quant-ph↗

arXiv2002

Entropy and Eschatology: A Comment on Kutrovatz's Paper "Heat Death in Ancient and Modern Thermodynamics"

Recent intriguing discussion of heat death by Kutrovatz is critically examined. It is shown that there exists another way of answering the heat death puzzle, already present in the ancient philosophical tradition. This alternative route relies not only on the final duration of time (which has been re-discovered in modern times), but also on the notion of observational self-selection, which has received wide publicity in the last several decades under the title of the anthropic principle(s). Although the questions Kutrovatz raises are important and welcome, there are several errors in his treatment of cosmology which marr his account of the entire topic. In addition, the nascent discipline of physical eschatology holds promise of answering the basic explanatory task concerning the future evolution of the universe without appealing to metaphysics. This is a completely novel feature in the history of science, in contradistinction to the historical examples discussed.

physics.hist-ph↗

arXiv2002

Forecast for the Next Eon: Applied Cosmology and the Long-Term Fate of Intelligent Beings

Cosmology seems extremely remote from everyday human practice and experience. It is usually taken for granted that cosmological data cannot rationally influence our beliefs about the fate of humanity -- and possible other intelligent species -- except perhaps in the extremely distant future, when the question of heat death (in an ever-expanding universe) becomes actual. Here, an attempt is made to show that it may become a practical issue much sooner, if an intelligent community wishes to maximize its creative potential. New developments in the fields of anthropic self-selection and physical eschatology give solid foundations to such a conclusion. This may open some new (and possibly urgent) issues in the areas of future policy making and transhumanist studies generally. It may also give us a slightly better perspective on the SETI endeavor.

astro-ph↗

arXiv2002

A Resource Letter on Physical Eschatology

This Resource Letter treats the nascent discipline of physical eschatology, which deals with the future evolution of astrophysical objects, including the universe itself, and is thus both a counterpart and a complement to conventional cosmology. While sporadic interest in these topics has flared up from time to time during the entire history of humanity, a truly physical treatment of these issues has only become possible during the last quarter century. This Resource Letter deals with these recent developments. It offers a starting point for understanding what the physical sciences might say about the future of our universe and its constituents. Journal articles, books, and web sites are provided for the following topics: history and epistemology of physical eschatology, the future of the Solar system, the future of stars and stellar systems, the global future of the universe, information processing and intelligent communities, as well as some side issues, like the possible vacuum phase transition and the so-called Doomsday Argument.

astro-ph↗

arXiv2001

On the Maximal Quantity of Processed Information in the Physical Eschatological Context

An estimate of the maximal informational content available to advanced extraterrestrial or future (post)human civilizations is presented. It is shown that the fundamental thermodynamical considerations may lead to a quantitative estimate of the largest quantity of information to be processed by conceivable computing devices. This issue is interesting from the point of view of physical eschatology, as well as general futurological topics, like the degree of confidence in long-term physical predictions or viability of the large-scale simulations of complex systems.

astro-ph↗

arXiv2001

Is Many Likelier than Few? A Critical Assessment of the Self-Indicating Assumption

We analyze the arguments allegedly supporting the so-called Self-Indication Assumption (SIA), as an attempt to reject counterintuitive consequences of the Doomsday Argument of Carter, Leslie, Gott and others. Several arguments purportedly supporting this assumption are demonstrated to be either flawed or, at best, inconclusive. Therefore, no compelling reason for accepting SIA exists so far, and it should be regarded as an ad hoc hypothesis with several rather strange and implausible physical and epistemological consequences. Accordingly, if one wishes to reject the controversial consequences of the Doomsday Argument, a route different from SIA has to be found.

gr-qc↗

arXiv2001

Anthropic Fluctuations vs. Weak Anthropic Principle

A modern assessment of the classical Boltzmann-Schuetz argument for large-scale entropy fluctuations as the origin of our observable cosmological domain is given. The emphasis is put on the central implication of this picture which flatly contradicts the weak anthropic principle as an epistemological statement about the universe. Therefore, to associate this picture with the anthropic principle as it is usually done is unwarranted. In particular, Feynman's criticism of the anthropic principle based on the entropy-fluctuation picture is a product of this semantic confusion.

physics.hist-ph↗

arXiv2001

Is the Universe Really So Simple?

The intriguing suggestion of Tegmark (1996) that the universe--contrary to all our experiences and expectations--contains only a small amount of information due to an extremely high degree of internal symmetry is critically examined. It is shown that there are several physical processes, notably Hawking evaporation of black holes and non-zero decoherence time effects described by Plaga, as well as thought experiments of Deutsch and Tegmark himself, which can be construed as arguments against the low-information universe hypothesis. In addition, an extreme form of physical reductionism is entailed by this hypothesis, and therefore any possible argumentation against such reductionism would count against it either. Some ramifications for both quantum mechanics and cosmology are briefly discussed.

quant-ph↗

arXiv2001

Column density distribution of galactic Ly-alpha absorption systems

A simple consistency argument for hypothesis of the galactic halo origin of the Ly-alpha forest absorption lines is advanced, based on the recent determination of column-density vs. impact parameter relation for the low-redshift gaseous galactic haloes. It is shown that observations of neutral hydrogen absorption around luminous galaxies are consistent with the index of the power-law column density distribution derived from statistical analysis of large samples of high-redshift Ly-alpha forest lines.

astro-ph↗

arXiv2001

Laudatores Temporis Acti, or Why Cosmology is Alive and Well - A Reply to Disney

A recent criticism of cosmological methodology and achievements by Disney (2000) is assessed. Some historical and epistemological fallacies in the said article have been highlighted. It is shown that---both empirically and epistemologically---modern cosmology lies on sounder foundations than it is portrayed. A brief historical account demonstrates that this form of unsatisfaction with cosmology has had a long tradition, and rather meagre results in the course of the XX century.

astro-ph↗