If the physical constants, initial conditions, or laws of nature in our universe had been even slightly different, then the evolution of life would have been impossible. This observation has led many philosophers and scientists to ask the natural next question: why is our universe so "fine-tuned" for life? The debates around this question are wide-ranging, multi-disciplinary, complicated, technical, and heated. This study is a comprehensive investigation of these debates and the many metaphysical and epistemological questions raised by (...) class='Hi'>cosmological fine-tuning. Waller's study reaches two significant and controversial conclusions. First, he concludes that the criticisms directed at the "multiverse hypothesis" by theists and at the "theistic hypothesis" by naturalists are largely unsuccessful. Neither of these options can plausibly be excluded. Choosing between them seems to turn on primitive metaphysical intuitions. Second, in order to break the philosophical deadlock, Waller moves the debate from the level of universes to the level of possible worlds. Arguing that possible worlds are also "fine-tuned" in an important and interesting sense, Waller concludes that the only plausible explanation for the fine-tuning of the actual world is to posit the existence of some kind of "God-like-thing.". (shrink)

Jan Greben criticized fine-tuning by taking seriously the idea that “nature is quantum mechanical”. I argue that this quantum view is limited, and that fine-tuning is real, in the sense that our current physical models require fine-tuning. Second, I examine and clarify many difficult and fundamental issues raised by Rüdiger Vaas’ comments on Cosmological Artificial Selection.

This chapter considers two types of fine‐tuning, those dealing with the initial conditions of the universe and those based on fixed parameters. Three approaches have been taken to argue that fine‐tuning does not need any special explanation. The first is an appeal to coincidence. The second is that the data are biased by our own observations. The third has to do with the nature of probability itself. The chapter assesses each of these objections in detail. Many (...) naturalistic explanations have been offered for fine‐tuning. The chapter considers the three most important ones. The first is that future discoveries might show that fine‐tuning was not improbable after all. The second is that other life‐permitting ranges for the fine‐tuned constants (FTCs) might exist, allowing for exotic forms of life unlike ours. The third is that we might live in a multiverse of many different universes all with different values of FTCs. (shrink)

In this paper we propose that cosmological fine-tuning arguments, when levied in support of the existence of Intelligent Designers or Multiverses, are much less interesting than they are thought to be. Our skepticism results from tracking the distinction between merely epistemic or logical possibilities on one hand and nonepistemic possibilities, such as either nomological or metaphysical possibilities, on the other. We find that fine-tuning arguments readily conflate epistemic or logical possibilities with nonepistemic possibilities and we (...) think that this leads to treating the search for an explanation of fine-tuning as analogous to standard empirical theorizing about first-order nomological matters, when in fact the two investigational enterprises are profoundly different. Similar conflation occurs when fine-tuning arguments do not carefully distinguish between different interpretations of probabilities within the arguments. Finally, these arguments often rely on spatial analogies, which are often misleading precisely in that they encourage the conflation of epistemic and nonepistemic possibility. When we pay attention to the distinctions between merely epistemic versus nonepistemic modalities and probabilities, the extant arguments in favor of intelligent designers or multiverses, or even for the nonepistemic improbability of fine-tuning, consist of empirically unconstrained speculation concerning relevant nonepistemic modal facts. (shrink)

Evidence for instances of astrophysical 'fine tuning' (or 'coincidences') is thought by some to lend support to the design argument (i.e. the argument that our universe has been designed by some deity). We assess some of the relevant empirical and conceptual issues. We argue that astrophysical fine tuning calls for some explanation, but this explanation need not appeal to the design argument. A clear and strict separation of the issue of anthropic fine tuning on (...) one hand and any form of Eddingtonian numerology and teleology on the other, may help clarify arguably the most significant issue in the philosophy of cosmology. (shrink)

Fine-tuning in physics and cosmology is often used as evidence that a theory is incomplete. For example, the parameters of the standard model of particle physics are “unnaturally” small, which has driven much of the search for physics beyond the standard model. Of particular interest is the fine-tuning of the universe for life, which suggests that our universe’s ability to create physical life forms is improbable and in need of explanation, perhaps by a multiverse. This claim (...) has been challenged on the grounds that the relevant probability measure cannot be justified because it cannot be normalized, and so small probabilities cannot be inferred. We show how fine-tuning can be formulated within the context of Bayesian theory testing in the physical sciences. The normalizability problem is seen to be a general problem for testing any theory with free parameters, and not a unique problem for fine-tuning. Physical theories in fact avoid such problems in one of two ways. Dimensional parameters are bounded by the Planck scale, avoiding troublesome infinities, and we are not compelled to assume that dimensionless parameters are distributed uniformly, which avoids non-normalizability. (shrink)

The objective of this paper is analyzing to which extent the multiverse hypothesis provides a real explanation of the peculiarities of the laws and constants in our universe. First we argue in favor of the thesis that all multiverses except Tegmark’s “mathematical multiverse” are too small to explain the fine tuning, so that they merely shift the problem up one level. But the “mathematical multiverse" is surely too large. To prove this assessment, we have performed a number of (...) experiments with cellular automata of complex behavior, which can be considered as universes in the mathematical multiverse. The analogy between what happens in some automata (in particular Conway’s “Game of Life") and the real world is very strong. But if the results of our experiments can be extrapolated to our universe, we should expect to inhabit—in the context of the multiverse—a world in which at least some of the laws and constants of nature should show a certain time dependence. Actually, the probability of our existence in a world such as ours would be mathematically equal to zero. In consequence, the results presented in this paper can be considered as an inkling that the hypothesis of the multiverse, whatever its type, does not offer an adequate explanation for the peculiarities of the physical laws in our world. (shrink)

Evidence for instances of astrophysical ‘fine tuning’ (or ‘coincidences’) is thought by some to lend support to the design argument (i.e. the argument that our universe has been designed by some deity). We assess some of the relevant empirical and conceptual issues. We argue that astrophysical fine tuning calls for some explanation, but this explanation need not appeal to the design argument. A clear and strict separation of the issue of anthropic fine tuning on (...) one hand and any form of Eddingtonian numerology and teleology on the other, may help clarify arguably the most significant issue in the philosophy of cosmology. (shrink)

It is commonplace in discussions of modern cosmology to assert that the early universe began in a special state. Conventionally, cosmologists characterize this fine-tuning in terms of the horizon and flatness problems. I argue that the fine-tuning is real, but these problems aren't the best way to think about it: causal disconnection of separated regions isn't the real problem, and flatness isn't a problem at all. Fine-tuning is better understood in terms of a measure (...) on the space of trajectories: given reasonable conditions in the late universe, the fraction of cosmological histories that were smooth at early times is incredibly tiny. This discussion helps clarify what is required by a complete theory of cosmological initial conditions. (shrink)

Elliott Sober has recently argued that the cosmological design argument is unsound, since our observation of cosmic fine-tuning is subject to an observation selection effect (OSE). I argue that this view commits Sober to rejecting patently correct design inferences in more mundane scenarios. I show that Sober's view, that there are OSEs in those mundane cases, rests on a confusion about what information an agent ought to treat as background when evaluating likelihoods. Applying this analysis to the (...) design argument shows that our observation of fine-tuning is not rendered uninformative by an OSE. Design and the Anthropic Objection Previous responses to the Anthropic Objection Variations: experimental squads and survivor reunions Why there is no OSE in firing squad cases Application to the design argument. (shrink)

This volume addresses the role value judgments play in science. It is my contention that a particular research programme in modern physical cosmology rests crucially on a value judgment. Before making my case, let me introduce the following abbreviations for the following propositions.

There is an ongoing debate over cosmological fine-tuning between those holding that design is the best explanation and those who favor a multiverse. A small group of critics has recently challenged both sides, charging that their probabilistic intuitions are unfounded. If the critics are correct, then a growing literature in both philosophy and physics lacks a mathematical foundation. In this paper, I show that just such a foundation exists. Cosmologists are now providing the kinds of measure-theoretic arguments (...) needed to make the case for fine-tuning. Introduction Probability and infinite sets 2.1 No probability function 2.2 Arbitrary and wrong probability functions The measure of the universe The coarse-tuning objection Arbitrariness and error Conclusion. (shrink)

Studies in astrophysical cosmology have served to reveal the incomprehensible fine-tuning of the fundamental constants and cosmological quantities which must obtain if a universe like ours is to be life-permitting. Traditionally, such fine-tuning of the universe for life would have been taken as evidence of divine design. William Dembski’s ’generic chance elimination argument’ provides a framework for evaluating the hypothesis of design with respect to the fine-tuning of the universe. On Dembski’s model the (...) key to a design inference is the elimination of the competing alternatives of physical necessity and chance. In debates over fine-tuning, the former is represented by a ’theory of everything’, which would eliminate or significantly reduce the improbabilities of fine-tuning. The latter takes the shape of the ’many worlds hypothesis’, according to which a ’world ensemble’ of universes exist, thus providing purchase for the ’anthropic principle’. This paper assesses the relative merit. (shrink)

Many theists regard the claim that certain fundamental constants of nature are fine-tuned for life as the best scientific argument for the existence of God since Paley’s watch. Even atheist physicists find these so-called “anthropic coincidences” difficult to explain naturally and many think they need to invoke multiple universes and the so-called “anthropic principle” to do so. Certainly if there are many universes, fine-tuning is simple. Our universe is not fine-tuned for life. Life is fine-tuned (...) to our universe. While multiple universes are expected from modern cosmological theories, theists and some scientists object that invoking the unobservable is not science. Of course, God is unobservable too, so the best theists can claim is a standoff. (shrink)

Argues that many claims by theists are based on their misunderstanding of science. He looks at the specific parameters and shows that plausible reasons can be found for the values they have within the existing standard models of physics and cosmology.

Few topics in cosmology are as hotly debated as the Multiverse: for some it is untestable and hence unscientific; for others it is unavoidable and a natural extension of previous science. A third position is that it is seen to follow from other theories, but those other theories might themselves be seen as too speculative. The idea of fine-tuning has a similar status. Some of this disagreement might be due to misunderstanding, in particular the degree to which probability (...) distributions are necessary to interpret conclusions based on the Multiverse, especially with regard to the Anthropic Principle. I present undisputed facts, discuss some common misunderstandings, and investigate the role played by probability. The Multiverse is perhaps an important component necessary for interpreting cosmological and other physical parameters. (shrink)

This paper examines probabilistic versions of the fine-tuning argument for design (FTA), with an emphasis on the interpretation of the probability statements involved in such arguments. Three categories of probability are considered: physical, epistemic, and logical. Of the three possibilities, I argue that only logical probability could possibly support a cogent probabilistic FTA. However, within that framework, the premises of the argument require a level of justification that has not been met, and, it is reasonable to believe, will (...) not be met anytime soon. (shrink)

The claim that certain fundamental constants of nature are fine tuned for life and that this provides strong evidence for supernatural design is perhaps the best scientific argument for the existence of God since Paley’s watch. Even atheist physicists find these so called “anthropic coincidences” difficult to explain and need to invoke the Weak Anthropic Principle and multiple universes to do so. Certainly if there are many universes, fine tuning is simple. Our form of life was fined (...) tuned to our universe by evolution. While multiple universes are expected from modern cosmological theories, theists and some scientists object that invoking the unobservable is not science. Of course, God is unobservable too, so the best theists can claim is a standoff. This is the first in a series of columns based on a book in the works that attempts to show that the apparent fine tuning of fundamental constants can be understood from basic physics without invoking multiple universes. In some cases the explanation is provable. In other cases, it is not provable but plausible. Fine tuning by design is a God of the Gaps argument. The proponent has the burden if proving that no possible natural explanation can be found. Thus a plausible natural explanation is sufficient to defeat the argument. A list of thirty four parameters that seem to be fine tuned has been assembled by Rich Deem on the God and Science website. Several of Deem’s constants, such as the speed of light in a vacuum, c, Newton’s constant of gravity, G, and Planck’s constant, h, are just arbitrary numbers that are determined simply by the unit system you are using. They can be set equal to any number you want, except zero, with no impact on the physics. So no fine tuning can possibly be involved, just as the number p is not fine tuned. I will focus first on the five parameters that have the most significance because, if interpreted correctly, they seem to pretty much rule out almost any conceivable kind of life without fine tuning: · Ratio of electrons to protons · Ratio of electromagnetic force to gravity Expansion rate of the universe · Mass density of the universe · Cosmological constant I will admit that the features a universe would have for slightly different values of these parameters, all other parameters remaining the same, would render unlikely any form of life even remotely like ours, that is, one that is based on a lengthy process, chemical or otherwise, by which complex matter evolved from simpler matter. Let me discuss each in turn, with the last, the most difficult, reserved for a future column.. (shrink)

In this philosophical paper, we explore computational and biological analogies to address the fine-tuning problem in cosmology. We first clarify what it means for physical constants or initial conditions to be fine-tuned. We review important distinctions such as the dimensionless and dimensional physical constants, and the classification of constants proposed by Lévy-Leblond. Then we explore how two great analogies, computational and biological, can give new insights into our problem. This paper includes a preliminary study to examine the (...) two analogies. Importantly, analogies are both useful and fundamental cognitive tools, but can also be misused or misinterpreted. The idea that our universe might be modelled as a computational entity is analysed, and we discuss the distinction between physical laws and initial conditions using algorithmic information theory. Smolin introduced the theory of "cosmological natural selection" with a biological analogy in mind. We examine an extension of. (shrink)

Cosmological inflation is widely considered an integral and empirically successful component of contemporary cosmology. It was originally motivated by its solution of certain so-called fine-tuning problems of the hot big bang model, particularly what are known as the horizon problem and the flatness problem. Although the physics behind these problems is clear enough, the nature of the problems depends on the sense in which the hot big bang model is fine-tuned and how the alleged fine- (...) class='Hi'>tuning is problematic. Without clear explications of these, it remains unclear precisely what problems inflationary theory is meant to be solving and whether it does in fact solve them. I analyze the structure of these problems and consider various interpretations that may substantiate the alleged fine-tuning. On the basis of this analysis I argue that at present there is no unproblematic interpretation available for which it can be said that inflation solves the big bang model’s alleged fine-tuning problems. (shrink)

Contemporary physics and cosmology have accumulated a great deal of empirical evidence for the claim that in order for our universe to contain life, an array of incredibly precise laws, constants, and specific initial conditions had to be in place. The minuscule odds of this happening purely by chance have prompted some Christian thinkers to suggest that this can be seen as novel evidence that the universe was fine-tuned specifically to give rise to biological life. And yet some Christian (...) thinkers also wish to make the case that molecular biology provides new evidence to the effect that life could not have arisen naturally in our universe, but rather that the origin of life required additional special divine intervention. There is at least a prima facie tension between these two ideas. Relatedly, some have raised the question of why, if the universe were fine-tuned for life, it was also set up in such a way that the origin of life was preceded by more than 10 billion years of lifelessness. If life was the whole point, why the seeming delay? In this paper I suggest a way Christian thinkers might address both issues: namely, the cosmos was not fine-tuned for life, but merely for the possibility of life. Perhaps God wanted a universe in which biological organisms were possible but in which their non-existence was also a live possibility. I develop this solution in dialogue with related ideas arising from the demonologies of St. Augustine, Boethius, and St. Anselm. (shrink)

Given the laws of our universe, the initial conditions and cosmological constants had to be "fine-tuned" to result in life. Is this evidence for design? We argue that we should be uncertain whether an ideal agent would take it to be so—but that given such uncertainty, we should react to fine-tuning by boosting our confidence in design. The degree to which we should do so depends on our credences in controversial metaphysical issues.

This new book by cosmologists Geraint F. Lewis and Luke A. Barnes is another entry in the long list of cosmology-centered physics books intended for a large audience. While many such books aim at advancing a novel scientific theory, this one has no such scientific pretense. Its goals are to assert that the universe is fine-tuned for life, to defend that this fact can reasonably motivate further scientific inquiry as to why it is so, and to show that the (...) multiverse and intelligent design hypotheses are reasonable proposals to explain this fine-tuning. This book's potential contribution, therefore, lies in how convincingly and efficiently it can make that case. (shrink)

We develop and apply a multi-dimensional conception of explanatory depth towards a comparative analysis of inflationary and bouncing paradigms in primordial cosmology. Our analysis builds on earlier work due to Azhar and Loeb (2021) that establishes initial condition fine-tuning as a dimension of explanatory depth relevant to debates in contemporary cosmology. We propose dynamical fine-tuning and autonomy as two further dimensions of depth in the context of problems with instability and trans-Planckian modes that afflict bouncing and (...) inflationary approaches respectively. In the context of the latter issue, we argue that the recently formulated trans-Planckian censorship conjecture leads to a trade-off for inflationary models between dynamical fine-tuning and autonomy. We conclude with the suggestion that explanatory preference with regard to the different dimensions of depth is best understood in terms of differing attitudes towards heuristics for future model building. (shrink)

According to the scenario of cosmological artificial selection and artificial cosmogenesis, our universe was created and possibly even fine-tuned by cosmic engineers in another universe. This approach shall be compared to other explanations, and some far-reaching problems of it shall be discussed.

We begin with a discussion of the Borde-Guth-Vilenkin past-incompleteness theorem for inflationary universes and discuss its significance for various pre-big-bang inflationary scenarios in string cosmology, including landscape and cyclic ekpyrotic models. We then undertake a general critique of inflationary cosmology in respect of its stated goals and conclude with a critcal discussion of the string-theoretic multiverse as a "solution" to the problem of cosmological fine-tuning.

This chapter contains sections titled: Theism and Physical Cosmogony Theism and Physical Eschatology The Fine‐Tuning of the Universe for Intelligent Life Works cited.

This paper deals with one of the basic philosophical questions in modern cosmology: can the so-called Anthropic Principle , considered as an alternative to the classical teleology of creation, be an adequate explanation of the evidence that our universe is fine-tuned for the emergence of life and consciousness. The main problem with this principle is not its presumed teleology, as it is sometimes wrongly supposed, but quite the contrary: its intention to avoid teleological explanations by including the existence of (...) many universes ( multiverse ) into extended cosmological models. After having compared logical and cosmological many-worlds concepts, this paper reaches the conclusion that the ontological reality of the multiverse is an even more problematic presupposition than some properly revised version of teleological causality. This in itself does not imply the classical theistic explanation of creation, since it also yields a pantheistic explanation of the emergence of life and consciousness in our universe. (shrink)

We develop and apply a multi-dimensional account of explanatory depth towards a comparative analysis of inflationary and bouncing paradigms in primordial cosmology. Our analysis builds on earlier work due to Azhar and Loeb (2021) that establishes initial conditions fine-tuning as a dimension of explanatory depth relevant to debates in contemporary cosmology. We propose dynamical fine-tuning and autonomy as two further dimensions of depth in the context of problems with instability and trans-Planckian modes that afflict bouncing and (...) inflationary approaches respectively. In the context of the latter issue, we argue that the recently formulated trans-Planckian censorship conjecture leads to a trade-off for inflationary models between dynamical fine-tuning and autonomy. We conclude with the suggestion that explanatory preference with regard to the different dimensions of depth is best understood in terms of differing attitudes towards heuristics for future model building. (shrink)

This paper characterizes various responses to the question, 'Why does our universe exist?' Some responses- that the question is senseless, that the existence of our universe is logically necessary- are implausible. Adjudication between more plausible responses requires us to evaluate the argument from the 'fine-tuning' of the universe, a refurbished version of the argument from design that appeals to cosmology rather than biology. The evidence of fine-tuning should lead us to adopt, albeit provisionally, cosmological fecundity, (...) the hypothesis that there exist many universes of varying characters. The existence of our universe is thereby rendered less surprising. This is to be preferred both to the theistic hypothesis and to the view that the existence of our universe requires no explanation. (shrink)

The cosmological theory of the author, discussed in (Greben in Found Sci 15(2):153–176, 2010 ), has a number of implications for the interpretation of initial conditions and the fine-tuning problem as discussed by Vidal (Found Sci 15(4):375–393, 2010a ).

Several physicists, among them Hawking, Page, Coule, and Carroll, have argued against the probabilistic intuitions underlying fine-tuning arguments in cosmology and instead propose that the canonical measure on the phase space of Friedman-Robertson-Walker space-times should be used to evaluate fine-tuning. They claim that flat space-times in this set are actually typical on this natural measure and that therefore the flatness problem is illusory. I argue that they misinterpret typicality in this phase space and, moreover, that no (...) conclusion can be drawn at all about the flatness problem by using the canonical measure alone. (shrink)

The successes scored by the big bang model of cosmic evolution in the 1960’s led to an intensive application of quantum theory to the problem of how the expansion might have begun and what its likely first stages were. It seemed as though an incredibly precise setting of the initial conditions would have been needed in order that a long-lived galactic universe containing heavy elements might develop. One response was to suppose that the fine-tuning could somehow be explained (...) by the presence of humans in the universe. This ran quite counter to the traditional supposition, according to which an initial "chaos" was sufficient. This essay outlines the history of the two principles, argues that the so-called "weak" anthropic principle is banal, distinguishes between two sorts of anthropic explanation, and assesses the prospects of the anthropic turn in cosmology. (edited). (shrink)

This paper criticises the cosmological argument that Tim O'Connor provides in his book *Theism and Ultimate Explanation*.

Some physical theories predict that almost all brains in the universe are Boltzmann brains, i.e. short-lived disembodied brains that are accidentally assembled as a result of thermodynamic or quantum fluctuations. Physicists and philosophers of physics widely regard this proliferation as unacceptable, and so take its prediction as a basis for rejecting these theories. But the putatively unacceptable consequences of this prediction follow only given certain philosophical assumptions. This paper develops a strategy for shielding physical theorizing from the threat of Boltzmann (...) brains. The strategy appeals to a form of phenomenal externalism about the physical basis of consciousness. Given that form of phenomenal externalism, the proliferation of Boltzmann brains turns out to be benign. While the strategy faces a psychophysical fine-tuning problem, it both alleviates cosmological fine-tuning concerns that attend physics-based solutions to Boltzmann brain problems and pays explanatory dividends in connection with time’s arrow. (shrink)

There seems to be a widespread conviction — evidenced, for example, in the work of Mackie, Dawkins and Sober — that it is Darwinian rather than Humean considerations which deal the fatal logical blow to arguments for intelligent design. I argue that this conviction cannot be well-founded. If there are current logically decisive objections to design arguments, they must be Humean — for Darwinian considerations count not at all against design arguments based upon apparent cosmological fine-tuning. I (...) argue, further, that there are good Humean reasons for atheists and agnostics to resist the suggestion that apparent design — apparent biological design and/or apparent cosmological fine-tuning — establishes (or even strongly supports) the hypothesis of intelligent design. (shrink)

Since Collins and Hawking described the need for an unimaginably precise flatness in the early universe, many have argued that the cosmos thereby requires design. This essay traces the developments of these design speculations from the Collins-Hawking discovery in 1973 to the present, and describes the four possible responses that are available to the apparent fine-tuning of the universe.

Our examination of universal origins and fine-tuning will begin with a discussion of infl ationary scenarios grafted onto Big Bang cosmology and the proof that all infl ationary spacetimes are past-incomplete. After diverting into a lengthy critical examination of the “different physics” offered by quantum cosmologists at the past-boundary of the universe, we will proceed to dissect the inadequacies of infl ationary explanations and string-theoretic constructs in the context of three cosmological models that have received much attention: (...) the Steinhardt-Turok cyclic ekpyrotic model (which does not invoke inflation), the Gasperini-Veneziano pre-Big Bang infl ationary model, and the inflationary string landscape model advanced by Susskind, Polchinski, Bousso, and Linde. We will argue that none of these highly speculative string cosmologies removes the necessity of a beginning to the process of universe generation, and we will emphasize the implications of this fact. Then, since the inflationary “mechanism” only really addresses the fi ne-tuning of the initial conditions of the universe and not the conditions embodied in its finely tuned laws and constants, we will analyze the adequacy of the string multiverse in its three versions (cyclic ekpyrotic, pre-Big Bang, and landscape) for explaining the nomological structure and values of these precisely tuned life-compatible universal parameters. When all is said and done, it will be clear that transcendent intelligent agency is not just the only causally suffi cient and therefore metaphysically sound explanation for universal origins and fine-tuning, but it is also much more parsimonious, elegant, and resonant with meaning than all of the ad hoc machinations of multiverse cosmology. (shrink)

In this fascinating journey to the edge of science, Vidal takes on big philosophical questions: Does our universe have a beginning and an end or is it cyclic? Are we alone in the universe? What is the role of intelligent life, if any, in cosmic evolution? Grounded in science and committed to philosophical rigor, this book presents an evolutionary worldview where the rise of intelligent life is not an accident, but may well be the key to unlocking the universe's deepest (...) mysteries. Vidal shows how the fine-tuning controversy can be advanced with computer simulations. He also explores whether natural or artificial selection could hold on a cosmic scale. In perhaps his boldest hypothesis, he argues that signs of advanced extraterrestrial civilizations are already present in our astrophysical data. His conclusions invite us to see the meaning of life, evolution and intelligence from a novel cosmological framework that should stir debate for years to come. (shrink)

Some physical aspects of Teilhard's synthesis are focused upon and confronted with the recent achievements of physics and cosmology. The stuff of the universe, according to modern physical theories, has become something more similar to a structure or form than to inert pieces of material substratum. Directedness of time and history no longer seems to be an ontological a priori of any existence, but rather an outcome of finely tuned initial conditions. And the growth of complexity is now regarded as (...) a process emerging out of physical laws rather than a foreign element in the body of physics. The question is considered of how these results affect Teilhard de Chardin's vision of the world. (shrink)

In the last three decades several cosmological principles and styles of reasoning termed 'anthropic' have been introduced into physics research and popular accounts of the universe and human beings' place in it. I discuss the circumstances of 'fine tuning' that have motivated this development, and what is common among the principles. I examine the two primary principles, and find a sharp difference between these 'Weak' and 'Strong' varieties: contrary to the view of the progenitors that all anthropic (...) principles represent a departure from Copernicanism in cosmology, the Weak Anthropic Principle is an instance of Copernicanism. It has close affinities with the step of Copernicus that Immanuel Kant took himself to be imitating in the 'critical' turn that gave rise to the Critique of Pure Reason. I conclude that the fact that a way of going about natural science mentions human beings is not sufficient reason to think that it is a subjective approach; in fact, it may need to mention human beings in order to be objective. (shrink)

Fine-tuning arguments are a frequent find in the literature on quantum field theory. They are based on naturalness—an aesthetic criterion that was given a precise definition in the debates on the Higgs mechanism. We follow the history of such definitions and of their application at the scale of electroweak symmetry breaking. They give rise to a special interpretation of probability, which we call Gedankenfrequency. Finally, we show that the argument from naturalness has been extended to comparing different models (...) of the physics beyond the Standard Model and that naturalness in this case can at best be understood a socio-historic heuristic. (shrink)

The twenty-one readings collected by Leslie address four main questions: Was there a Big Bang? Is our universe "fine-tuned" to life's needs such that the most minute changes would have made life-forms impossible? Are there multiple universes? Is there life elsewhere in the cosmos? A brief survey of a sampling of the readings will convey the scope of this volume.

Cosmologists often claim that our universe is “fine tuned” for life. A change by 1% in the strong nuclear force would have meant little carbon would exist, and carbon can seem biologically essential. Again, the riches of chemistry and biochemistry depend on the neutron’s being heavier than the proton by no more than 0.1%. The early cosmic expansion rate may have needed fine tuning to one part in l055 to prevent speedy recollapse and speedy disintegration. To prevent (...) excess turbulence the “smoothness” perhaps needed fine tuning to one part in 10 raised to the power of 10123 (a number far greater than 101230). Etcetera (Leslie 1982, 1983a, 1985, 1986).The list of such claims is very long. No doubt some of its items are mistakes. Others may be dictated by basic physics so that they are not fine-tunable. (shrink)