Several works in the last few years devoted to measure fundamental probes of contemporary cosmology have suggested the existence of a delocalized dominant component (the "dark energy"), in addition to the several-decade-old evidence for "dark matter" other than ordinary baryons, both assuming the description of gravity to be correct. Either we are faced to accept the ignorance of at least 95 % of the content of the universe or consider a deep change of the conceptual framework to understand the data. Thus, the situation seems to be completely favorable for a Kuhnian paradigm shift in either particle physics or cosmology. We attempt to offer here a brief discussion of these issues from this particular perspective, arguing that the situation qualifies as a textbook Kuhnian anomaly, and offer a tentative identification of some of the actual elements typically associated with the paradigm shift process "in the works" in contemporary science.
Deep Dive into Dark matter, dark energy and modern cosmology: the case for a Kuhnian paradigm shift.
Several works in the last few years devoted to measure fundamental probes of contemporary cosmology have suggested the existence of a delocalized dominant component (the “dark energy”), in addition to the several-decade-old evidence for “dark matter” other than ordinary baryons, both assuming the description of gravity to be correct. Either we are faced to accept the ignorance of at least 95 % of the content of the universe or consider a deep change of the conceptual framework to understand the data. Thus, the situation seems to be completely favorable for a Kuhnian paradigm shift in either particle physics or cosmology. We attempt to offer here a brief discussion of these issues from this particular perspective, arguing that the situation qualifies as a textbook Kuhnian anomaly, and offer a tentative identification of some of the actual elements typically associated with the paradigm shift process “in the works” in contemporary science.
Thomas S. Kuhn (1922-1996) in the 20th century imprinted a strong pattern under which scientific research is seen today. Even philosophers, historians and epistemologists which disagree with his views about these subjects still find difficult to avoid a discussion for or against Kuhn's own framework (see, for example, S. Fuller ' Is There Philosophical Life after Kuhn? , Philosophy of Science, v. 68, 2001, 565-572 1 ).
In his book 2 The Structure of Scientific Revolutions the author discussed in a long essay style the basic concepts and operating mechanisms of the scientific enterprise, quite often resorting to a normative viewpoint. Scientific progress is seen mainly as a succession of paradigm shifts between periods of “normal science”, inside which the task of the scientists is rather to confirm and reinforce the existing paradigms. The boundaries of these “normal science” periods have been termed by him scientific revolutions, truly extraordinary episodes in the research history, triggered by the repeated failure in solving a (big) problem(s) in the field and/or a new discovery shaking the very field foundations and not easily fitted into the existing paradigm. The latter concept may be in turn defined the sum of the theories and value commitments shared by the scientific group, later rephrased provisionally as “discipline matrix” for this specific meaning. According to this definition, the scientific groups are bound by theories but also other elements (concepts, procedures and even symbolic generalizations usually called “laws” such as Newton’s -→ f = m × -→ a and a similar entities), constituting the common grounds on which research is conducted. Scientific research is thus seen from a common context (gestalt), and it is only when the efforts to fit a problem/phenomenon into the paradigm fail repeatedly that “extraordinary science” sets in, and is accepted (or rather, tolerated) by traditionalists in search of a more satisfactory understanding. A lot of criticism has been published against these ideas, and sometimes bold extrapolations of them constructed for application in other fields, like public policies and pedagogy. In addition, the Kuhnian perspective has been recognized as akin to Darwinian evolution, or rather to the stasis theory of Eldredge and Gould 3 postulating punctuated equilibrium of biological evolution instead of a gradual and continuous change of life forms.
Cases which may be considered textbook examples of the paradigm shift are known in several sciences (although never without some dispute). They range from truly big, ground-shaking revolutions such as the well-known Copernican and Newtonian; to smaller and more specialized events like the emergence of gauge principles in field theory. A more recent possible example, to which this work is devoted, is the case of modern cosmology in which one set of new facts is being widely discussed and seeking for a comprehensive global picture, still absent or very blurred. Because of its importance we shall outline the scientific case in some extent (but keeping technical details to a minimum) in the next section, with emphasis to the connections to previous ideas and results. The accelerated Universe Quite recently the interest in astrophysics and cosmology bloomed boosted by the advance of technological facilities, and allowed a series of studies which reached and captured the imagination of the public opinion. Specifically, cosmology has been highlighted by the reports from 1998 on about the acceleration of the universe seen in studies of type Ia supernovae 4,5,6 with an indication of a non-zero value of a delocalized component known as “dark energy” (hereafter dark energy) as a possible (but not unique) solution.
The argument for suck a remarkable claim is as follows. Type Ia supernovae form a class of stellar explosions long associated to the death of an “old” evolved star. This general statements relies on the fact that, in contrast to other explosive events (known as type Ib, or type II) hydrogen is absent in the ejected gas. Therefore, it is concluded that the exploding star had exhausted the hydrogen and hence, it must have evolved from the hydrogen-burning phase well before the event. What is a crucial step, and forms the basis of the cosmological analysis is the contention that type Ia supernovae are quite homogeneous as long as their absolute brightness is considered, and therefore form a set of standard candles. In addition, a remarkable relation between the maximum brightness and a time interval defined properly from the rise of the lightcurve to its decline has been discovered 7 , a feature that allows a further calibration of the astronomical magnitudes (that is, to infer the absolute brightness and to put a distance for each source).
When these explosions are observed in distant galaxies, affected by the expansion of the universe as discovered by Hubble and confirmed in several detailed works, their distances inferred b
…(Full text truncated)…
This content is AI-processed based on ArXiv data.
