A fully micro realistic, propensity version of quantum theory is proposed, according to which fundamental physical entities - neither particles nor fields - have physical characteristics which determine probabilistically how they interact with one another . The version of quantum "smearon" theory proposed here does not modify the equations of orthodox quantum theory: rather, it gives a radically new interpretation to these equations. It is argued that there are strong general reasons for preferring quantum "smearon" theory to orthodox quantum theory; (...) the proposed change in physical interpretation leads quantum "smearon" theory to make experimental predictions subtly different from those of orthodox quantum theory. Some possible crucial experiments are considered. (shrink)

Even those generally skeptical of propensity interpretations of probability must now grant the following two points. First, the above single-case propensity interpretation meets recognized formal conditions for being a genuine interpretation of probability. Second, this interpretation is not logically reducible to a hypothetical relative frequency interpretation, nor is it only vacuously different from such an interpretation.The main objection to this propensity interpretation must be not that it is too vague or vacuous, but that it is metaphysically too extravagant. It asserts (...) not only that there are physical possibilities in nature, but further that nature itself contains innate tendencies toward these possibilities, tendencies which have the logical structure of probabilities. Thus the basic dispute between advocates of an actualist relative frequency interpretation and a single-case propensity interpretation is not a matter of epistemology, but metaphysics. The frequency theorist wishes to maintain that claims about physical probabilities are nothing more than claims about relative frequencies that will occur in the actual history of the world, be it infinite or no. It is a substantial, though hardly conclusive, argument for the propensity view that the mathematical structures commonly employed in studies of stochastic processes and statistical inference are richer than can be accommodated by a relative frequency interpretation. Whether it is possible to bridge this gap without going beyond an actualist metaphysics remains to be seen.38. (shrink)

I present a formal ontological theory where the basic building blocks of the world can be either things or events. In any case, the result is a Parmenidean worldview where change is not a global property. What we understand by change manifests as asymmetries in the pattern of the world-lines that constitute 4-dimensional existents. I maintain that such a view is in accord with current scientific knowledge.

I present a condensed exposé of systemic materialism, a synthesis of materialism and systemism originally proposed by Mario Bunge. Matter is identified with mutability of propertied particulars, and a concrete or material system is defined as an object with composition, structure, mechanism, and environment. I review different aspects of this ontology, and discuss some of its implications for epistemology, ethics, and aesthetics. I also try to identify some problems of this view and offer some ways to overcome the difficulties. I (...) conclude that systemic materialism is a promising philosophical project still in the making. (shrink)

The idea of a moving present or ‘now’ seems to form part of our most basic beliefs about reality. Such a present, however, is not reflected in any of our theories of the physical world. I show in this article that presentism, the doctrine that only what is present exists, is in conflict with modern relativistic cosmology and recent advances in neurosciences. I argue for a tenseless view of time, where what we call ‘the present’ is just an emergent secondary (...) quality arising from the interaction of perceiving self-conscious individuals with their environment. I maintain that there is no flow of time, but just an ordered system of events. (shrink)

A supertask consists in the performance of an infinite number of actions in a finite time. I show that any attempt to carry out a supertask will produce a divergence of the curvature of spacetime, resulting in the formation of a black hole. I maintain that supertaks, contrarily to a popular view among philosophers, are physically impossible. Supertasks, literally, collapse under their own weight.

I argue that there are no physical singularities in space–time. Singular space–time models do not belong to the ontology of the world, because of a simple reason: they are concepts, defective solutions of Einstein’s field equations. I discuss the actual implication of the so-called singularity theorems. In remarking the confusion and fog that emerge from the reification of singularities I hope to contribute to a better understanding of the possibilities and limits of the theory of general relativity.

I argue for a four dimensional, non-dynamical view of space-time, where becoming is not an intrinsic property of reality. This view has many features in common with the Parmenidean conception of the universe. I discuss some recent objections to this position and I offer a comparison of the Parmenidean space-time with an interpretation of Heraclitus’ thought that presents no major antagonism.

Black holes are arguably the most extraordinary physical objects we know in the universe. Despite our thorough knowledge of black hole dynamics and our ability to solve Einstein’s equations in situations of ever increasing complexity, the deeper implications of the very existence of black holes for our understanding of space, time, causality, information, and many other things remain poorly understood. In this paper I survey some of these problems. If something is going to be clear from my presentation, I hope (...) it will be that around black holes science and metaphysics become more interwoven than anywhere else in the universe. (shrink)

This brief review of Mario Bunge’s research on physics begins with an analysis of his masterpiece Foundations of Physics, and then it discusses his other contributions to the philosophy of physics. Following that is a summary of his more recent reactions to scientific discoveries in physics and a discussion of his position about non-locality in quantum mechanics, as well as his changing opinions on the nature of spacetime. The paper ends with a brief assessment of Bunge’s legacy concerning the foundations (...) of physics. (shrink)

This essay offers a discussion and contextualisation of a series of letters exchanged between Jordi Cat and Paul Feyerabend from 1989 to 1994. These letters provide insights into Feyerabend’s later thought on a variety of themes including quantum holism, the disunity of science, the development of logical empiricism, and science activism. In doing so, we provide some original analysis and exegesis of Feyerabend’s evolving views on scientific methodology and quantum mechanics by focusing on Feyerabend’s changing attitudes towards Bohm, Bohr, and (...) his eventual colleague Hans Primas and his later sympathies with the algebraic approach. We also highlight Feyerabend’s role in the growth of the Disunity of Science movement and how he connected disunity to practical considerations in the philosophy of action. (shrink)

The leitmotif of Mario Bunge’s work was that the philosophy of science should be informed by a comprehensive scientific philosophy, and vice versa; with both firmly rooted in realism and materialism. Now Bunge left such a big oeuvre, comprising more than 70 books and hundreds of articles, that it is impossible to review it in its entirety. In addition to biographical remarks, this obituary will therefore restrict itself to some select issues of his philosophy: his scientific metaphysics, his philosophy of (...) physics, his concept of mechanismic explanation, his philosophy of social science and technology, and his approach to the demarcation problem. The final section will explore why Bunge, despite the extent and depth of his work, has not achieved a more prominent status in the philosophical community. (shrink)

Up until recently social scientists took it for granted that their task was to account for the social world as objectively as possible: they were realists in practice if not always in their methodological sermons. This situation started to change in the 1960s, when a number of antirealist philosophies made inroads into social studies. -/- This paper examines critically the following kinds of antirealism: subjectivism, conventionalism, fictionism, social constructivism, relativism, and hermeneutics. An attempt is made to show that these philosophies (...) are false and are causing serious damage to social studies. -/- Next the subjective interpretation of probability is analyzed as a case of subjectivism. An approach to the subjective perception of justice is sketched as an example of the objective study of subjective experience. -/- Finally, the three main varieties of realism — naive, critical, and scientific — are outlined. It is argued that the scientific attitude involves scientific realism, which is put in practice even by scholars who, like Weber and Simmel, called themselves antirealists. (shrink)

This study considers the short list of Nature of Science features frequently published and widely known in the science education discourse. It is argued that these features were oversimplified and a refinement of the claims may enrich or sometimes reverse them. The analysis shows the need to address the range of variation in each particular aspect of NOS and to illustrate these variations with actual events from the history of science in order to adequately present the subject. Another implication of (...) the proposal is the highlighting of the central role of science educators who, facing various strong claims of researchers in education and philosophy of science, often have difficulty in making a choice of what to teach about NOS. It is suggested that a representative variation with regard to the traditional NOS claims may be appropriate for a genuine understanding of the subject. In that, using the discipline-culture structure of the fundamental theories of physics and addressing the plurality of scientific methods may be helpful in the actual teaching and learning of NOS. (shrink)

I discuss the ontological assumptions and implications of General Relativity. I maintain that General Relativity is a theory about gravitational fields, not about space-time. The latter is a more basic ontological category, that emerges from physical relations among all existents. I also argue that there are no physical singularities in space-time. Singular space-time models do not belong to the ontology of the world: they are not things but concepts, i.e. defective solutions of Einstein’s field equations. I briefly discuss the actual (...) implication of the so-called singularity theorems in General Relativity and some problems related to ontological assumptions of Quantum Gravity. (shrink)

In the first of these two studies it is argued that the discrepancy between the predicted and actual outcome of the Michelson-Morley experiment is due to the use of Newton's velocity addition theorem in conjunction with an electromagnetic theory of light. The ether hypothesis is not directly affected at all. The second study is a case study of the removal of a clash in physics generated from the outcome of an experiment. The clash due to the Michelson-Morley experiment gave rise (...) to a program of revision. In the process of implementation of this program Newtonian mechanics was remolded. It is argued that the Riemannian space-time in Einstein's general theory of relativity may be regarded as a successor of the classical ether. (shrink)

I discuss the recent claims made by Mario Bunge on the philosophical implications of the discovery of gravitational waves. I think that Bunge is right when he points out that the detection implies the materiality of spacetime, but I reject his identification of spacetime with the gravitational field. I show that Bunge’s analysis of the spacetime inside a hollow sphere is defective, but this in no way affects his main claim.

Original research is of course what scientists are expected to do. Therefore the research project is in many ways the unit of science in the making: it is the center of the professional life of the individual scientist and his coworkers. It is also the means towards the culmination of their specific activities: the original publication they hope to contribute to the scientific literature. The scientific project should therefore be of central interest to all the students of science, particularly the (...) philosophers and sociologists of science. We shall focus on the preliminary evaluation of research projects—the specific task of referees—and will emphasize the problem of their scientificity—the chief concern of scientific gatekeepers. In the past such an examination aimed only at protecting the taxpayer from swindlers and incompetent amateurs, such as the inventors of continuous motion artifacts. In recent times a similar issue has resurfaced with regard to some of the most prestigious and most handsomely funded projects, namely work on string theory and many-worlds cosmology. Indeed, some of their faithful have claimed that these theories are so elegant, and so full of high-grade mathematics, that they should be exempted from empirical tests. This claim provoked the spirited rebuttal of the well-known cosmologists Ellis and Silk, which the present paper is intended to reinforce. Indeed, we shall try to show why empirical testability is necessary though insufficient for a piece of work to qualify as scientific. Finally, the present paper may also be regarded as an indirect contribution to the current debate over the reliability of quantitative indicators of scientific worth, such as the h-index of scientific productivity. But we shall touch only tangentially on the sociological, political, and economics of research teams: our focus will be the acquisition of new scientific knowledge. (shrink)

We present an axiomatization of non-relativistic Quantum Mechanics for a system with an arbitrary number of components. The interpretation of our system of axioms is realistic and objective. The EPR paradox and its relation with realism is discussed in this framework. It is shown that there is no contradiction between realism and recent experimental results.

The concept of ideology is central to the understanding of the many political, economic, social, and cultural processes that have occurred in the last two centuries. And yet, what is the nature of the different ideologies remains a vague, open, and much disputed question. Many political, sociological, and ideological studies have been devoted to ideology. Very little, on the other hand, has been done from the philosophical field. And this despite the fact that there are undoubtedly many philosophical questions related (...) to ideology and its role in modern industrialized societies. Just a few examples of ideology-related philosophical questions suffice to prove the point: What objects do ideologies deal with? Are the ideologies testable? Are there true ideologies? Do they evolve? How are ideologies related to societies? Is the existence of ideologies inevitable in modern societies? What is the relation of ideology to science? Is science just another kind of ideology? Are we, as human beings, innately predisposed to believe in ideologies? Or, instead, ideologies proliferate through indoctrination and propaganda? Are ideologies necessarily harmful?...and much more. In this article I try to answer some of these questions from a philosophical point of view, taking a materialist approach. I begin by characterizing ideology as a complex, multi-layered concept. Then, I briefly discuss the material systems on which ideological movements operate, that is, societies and concrete human groups. I identify at least 11 different elements that seem to be present in most ideologies, and I compare these characteristics with those of contemporary science and technology. Although some superficial similarities can be identified, there are deep differences that make ideology completely different from science. The similarities, however, are stronger with technology. Ideologies continually evolve with technological advances, social changes, and even with mere fashion. The current fragmentation of ideologies caused by the widespread use of new technologies and social networks has given rise to new phenomena of ideological propagation which, in my opinion, are very dangerous, particularly for open societies. I discuss these processes, within the context of the nature vs nurture debate, along with the question of whether we can get rid of ideologies. (shrink)

I offer a formal ontological theory where the basic building blocks of the world are timeless events. The composition of events results in processes. Spacetime emerges as the system of all events. Things are construed as bundles of processes. I maintain that such a view is in accord with General Relativity and offers interesting prospects for the foundations of classical and quantum gravity.

The physicist's conception of space-time underwent two major upheavals thanks to the general theory of relativity and quantum mechanics. Both theories play a fundamental role in describing the same natural world, although at different scales. However, the inconsistency between them emerged clearly as the limitation of twentieth-century physics, so a more complete description of nature must encompass general relativity and quantum mechanics as well. The problem is a theorists' problem par excellence. Experiment provide little guide, and the inconsistency mentioned above (...) is an important problem which clearly illustrates the intermingling of philosophical, mathematical, and physical thought. In fact, in order to unify general relativity with quantum field theory, it seems necessary to invent a new mathematical framework which will generalise Riemannian geometry and therefore our present conception of space and space-time. Contemporary developments in theoretical physics suggest that another revolution may be in progress, through which a new kind of geometry may enter physics, and space-time itself can be reinterpreted as an approximate, derived concept. The main purpose of this article is to show the great significance of space-time geometry in predetermining the laws which are supposed to govern the behaviour of matter, and further to support the thesis that matter itself can be built from geometry, in the sense that particles of matter as well as the other forces of nature emerges in the same way that gravity emerges from geometry. Scientific research is not a process of steady accumulation of absolute truths, which has culminated in present theories, but rather a much more dynamic kind of process in which there are no final theoretical concepts valid in unlimited domains. (David Bohm). (shrink)

In current philosophical debate Bell's theorem is often refered to as a proof of the impossibility of determinism in nature. It is argued here that this conclusion is wrong. The main consequence of the theorem is the non-local character of quantum theory itself and it is shown how this quality leads to a contradiction with the theory of relativity. If hidden variable theories are impossible, it is so because no empirically founded interpretation at all can be compatible with both quantum (...) mechanics and relativity. (shrink)

I offer an analysis of the Principle of Sufficient Reason and its relevancy for the scientific endeavour. I submit that the world is not, and cannot be, rational—only some brained beings are. The Principle of Sufficient Reason is not a necessary truth nor a physical law. It is just a guiding metanomological hypothesis justified a posteriori by its success in helping us to unveil the mechanisms that operate in Nature.

Exposed in 1948, within his masterpiece on the scope and limits of human knowledge, the epistemological tenets that Bertrand Russell regarded as fundamental elements in the construction of scientific knowledge, are still worthy of a detailed discussion today. Given the excellence of the author, it will not be surprising to see that Russell's gnoseologic postulates, even for the present scientific view, address some of the most controversial questions still to be solved in the theory of knowledge.

A new interpretation of quantum theory is proposed. It coincides in a number of points with the orthodox interpretation, the main difference being that the projection of the state vector can occur without the intervention of any observer.

O. The idea of scientific progress in contemporary philosophy of science. Explicating the concept of cognitive progress means at the same time articulating an ideal of science. A desirable ideal: explain a lot and offer certainty. 1. Working out the ideal with the "foundationalist-positivist" approach. If the question, "When is it rational to accept a theory?" is answered, "When it has sufficient inductive support," this leads to insoluble problems. Reactions to the collapse of this approach - especially relativism and theory (...) instrumentalism. 2. The Popperian alternative: rational theory preference despite fallibility of methods for determining truth or greater accuracy of representations. What good reasons can there be for the conjecture that one theory is superior to a competing theory in its achievement as a description? Achievements to date as fallible but objective indicators of strength in describing. The sorts of risks for a theory differ in explanation and in prediction. Corresponding to the risks are the chances for cognitive progress. Instead of a cumulative index, itemized indication of success and failure in explanation and prediction with regard for importance of the questions at issue. On the concept of the "scientific importance" of questions. Postscript: On the political consequences of the sceptical position in philosophy of science. (shrink)

Ce texte est le fruit d’une collaboration entre un astrophysicien, Jean-René Roy, et un philosophe de l’éducation, Normand Baillargeon. Ils ont en commun d’avoir été marqués par la fréquentation des oeuvres de Mario Bunge, auxquelles ils attachent un grand prix, sur un plan personnel, d’abord, mais aussi, et c’est ce qu’ils veulent rappeler dans ces pages : parce qu’ils estiment que les oeuvres de Bunge contribuent de manière extrêmement forte et positive à rendre plus salubre la vie de l’esprit, en (...) enrichissant notre intellect et en luttant contre diverses formes troublantes d’obscurantisme qui y sévissent parfois, notamment dans les domaines familiers aux deux auteurs. (shrink)

Axiomatization is uncommon outside mathematics, partly for being often viewed as embalming, partly because the best-known axiomatizations have serious shortcomings, and partly because it has had only one eminent champion, namely David Hilbert. The aims of this paper are to describe what will be called dual axiomatics, for it concerns not just the formalism, but also the meaning of the key concepts; and to suggest that every instance of dual axiomatics presupposes some philosophical view or other. To illustrate these points, (...) a theory of solidarity will be crafted and axiomatized, and certain controversies in both classical and quantum physics, as well as in the philosophy of mind, will be briefly discussed. The upshot of this paper is that dual axiomatics, unlike the purely formal axiomatics favored by the structuralists school, is not a luxury but a tool helping resolve some scientific controversies. (shrink)

Macroscopic irreversible processes emerge from fundamental physical laws of reversible character. The source of the local irreversibility seems to be not in the laws themselves but in the initial and boundary conditions of the equations that represent the laws. In this work we propose that the screening of currents by black hole event horizons determines, locally, a preferred direction for the flux of electromagnetic energy. We study the growth of black hole event horizons due to the cosmological expansion and accretion (...) of cosmic microwave background radiation, for different cosmological models. We propose generalized McVittie co-moving metrics and integrate the rate of accretion of cosmic microwave background radiation onto a supermassive black hole over cosmic time. We find that for flat, open, and closed Friedmann cosmological models, the ratio of the total area of the black hole event horizons with respect to the area of a radial co-moving space-like hypersurface always increases. Since accretion of cosmic radiation sets an absolute lower limit to the total matter accreted by black holes, this implies that the causal past and future are not mirror symmetric for any spacetime event. The asymmetry causes a net Poynting flux in the global future direction; the latter is in turn related to the ever increasing thermodynamic entropy. Thus, we expose a connection between four different “time arrows”: cosmological, electromagnetic, gravitational, and thermodynamic. (shrink)

[[THIS IS THE COMPLETE THIRD ISSUE OF MΕTASCIENCE]] -/- This third issue of the journal Mεtascience continues the characterization of this new branch of knowledge that is metascience. If it is new, it is not in a radical sense since Mario Bunge practiced it in an exemplary way, since logical positivists were accused of practicing only a mere metascience, since scientists have always practiced it implicitly, and since some philosophers no longer practice philosophy but rather metascience, but without characterizing it (...) or theorizing it, that is, without realizing that they have abandoned one general discourse for another. The novelty therefore lies in this awareness that a general discourse without philosophy is possible: a scientific general discourse. -/- The ten contributions gathered in this volume illustrate the metascientific approach to knowledge of the world as well as to knowledge of knowledge of the world, that is, science. And like Bunge’s project, they are neither part of the analytical movement nor the continental movement in philosophy. We will read here studies about the Bungean system, some applications of Bungean thought, some metascientific contributions, and some reflections around metascience. -/- Among metascientific disciplines, epistemology occupies a prominent place in this issue of Mεtascience. Metascience differs from philosophy in its rejection of the fundamental philosophical distinction between appearance and reality. Metascientific epistemology therefore does not postulate the existence of any metaphysical reality. But metascientific epistemology, no more than philosophical ontology, is a factual science. The first, because it studies scientific constructs and not concrete objects, the second, because it is interested in transcendent or metaphysical objects. (shrink)

We critically examine the role and status probabilities, as they enter via the Quantum Equilibrium Hypothesis, play in the standard, deterministic interpretation of deBroglie’s and Bohm’s Pilot Wave Theory (dBBT), by considering interpretations of probabilities in terms of ignorance, typicality and Humean Best Systems, respectively. We argue that there is an inherent conflict between dBBT and probabilities, thus construed. The conflict originates in dBBT’s deterministic nature, rooted in the Guidance Equation. Inquiring into the latter’s role within dBBT, we find it (...) explanatorily redundant (in particular for dBBT’s solution of the Measurement Problem, which only requires that the corpuscles possess definite positions), and subject to a number of difficulties. Following a suggestion from Bell, we propose to abandon the Guidance Equation, whilst retaining dBBT’s point particle-based Primitive Ontology, with positions as local beables. The resultant theory, which we identify as a stochastic, minimally deBroglie-Bohmian theory, describes a random walk through configuration space. Its probabilities, we propose, are best understood as dispositions of possible corpuscle configurations to manifest themselves. We subsequently evaluate the merits of sdBBT vis-à-vis dBBT, such as the justification of the Symmetrisation Postulate and the violation of the Action-Reaction Principle. Not only is sdBBT an attractive Bohmian theory that, whilst retaining dBBT's virtues, overcomes many of its shortcomings; it also sparks off a number of exciting follow-up questions, such as a comparison between sdBBT and other stochastic hidden-variable theories, e.g. Nelson Stochastics, or between sdBBT and the Everett interpretation. (shrink)

We assume, in the first place, that two kinds of processes occur in nature: the strictly continuous and causal ones, which are governed by the Schrödinger equation and those implying discontinuities, which are ruled by probability laws. In the second place, we adopt a postulate ensuring the statistical sense of conservation laws. These hypotheses allow us to state a rule telling, in principle, in which situations and to which vectors the system's state can collapse, and which are the corresponding probabilities. (...) The way our proposed approach works is illustrated with some examples and with the analysis of the measurement problem. We obtain the exponential decay law. A comparison with other attempts to solve the measurement problem is performed. (shrink)

We analyse the various conceptual notions that go under the umbrella “relationalism/substantivalism”. Our focus will be on evaluating the ontological status of spacetime in General Relativity. To this end we systematically develop the ontological framework that implicitly underlies the traditional debate and common understanding of physics. We submit that spacetime with its chronogeometric and inertial structure, represented by the triple of the bare manifold, the metric and the affine structure, is best construed as the totality of possible and actual spatiotemporal (...) relations of events. This can explain the non-fundamentality of general relativistic gravitational energy and suggests a non-causal, non-interactional understanding of the interdependence of matter in spacetime in GR. (shrink)

Since its inception, the intricate mathematical formalism of quantum mechanics has empowered physicists to describe and predict specific physical events known as quantum processes. However, this success in probabilistic predictions has been accompanied by a profound challenge in the ontological interpretation of the theory. This interpretative complexity stems from two key aspects. Firstly, quantum mechanics is a fundamental theory that, so far, is not derivable from any more basic scientific theory. Secondly, it delves into a realm of invisible phenomena that (...) often contradicts our intuitive and commonsensical notions of matter and causality. Despite its notorious difficulties of interpretation, the most widely accepted set of views of quantum phenomena has been known as the Copenhagen interpretation since the beginning of quantum mechanics. According to these views, the correct ontological interpretation of quantum mechanics is incompatible with ontological realism in general and with philosophical materialism in particular. Anti-realist and anti-materialist interpretations of quantum matter have survived until today. This paper discusses these perspectives, arguing that materialistic interpretations of quantum mechanics are compatible with its mathematical formalism, while anti-realist and anti-materialist views are based on wrong philosophical assumptions. However, although physicalism provides a better explanation for quantum phenomena than idealism, its downward reductionism prevents it from accounting for more complex forms of matter, such as biological or sociocultural systems. Thus, the paper argues that neither physicalism nor idealism can explain the universe. I propose then a non-reductionistic form of materialism called inclusive materialism. The conclusion is that the acknowledgment of the qualitative irreducibility of ontological emergent levels above the purely physical one does not deny philosophical materialism but enriches it. (shrink)

The central thesis of this paper is that physicists have as much to learn from scientifically oriented philosophy as philosophers have to learn from physics. To begin with, any discussion of basic physical ideas and procedures is bound to be conducted in the light of some philosophy or other. Now, the standard philosophy of physics of our century is operationism. And philosophers, with the help of recent developments in semantics, epistemology and the theory of scientific inference, have shown that operationism (...) is untenable. Thus most physicists are dragging a dead philosophy that may not be of any help in conceiving of new ideas and procedures. This, then, is a first contribution philosophy can make to physics, namely to overhaul its philosophy. A second contribution is to the organization of physics, in particular to the axiomatic reconstruction of physical theories and the analysis and validation of empirical procedures. The various theses and antitheses discussed in the article are illustrated with examples taken from contemporary physics. (shrink)

We present three different derivations of the transition probabilities to the continuum. It is shown that calculations, performed as a direct application of the postulates of orthodox quantum mechanics (OQM), do not yield results consistent with experiments. Traditional treatments are summarized and criticized. The relation of the transitions to the continuum with the traditional quantum measurement problem is pointed out; we sum up and comment some contributions concerning this issue. It is shown that an approach based on the notion of (...) spontaneous projections yields expressions of the transition probabilities similar to those obtained in the traditional way and new predictions which could be submitted to experimental tests. (shrink)