On the persistence of the ether as absolute space

We present a novel -- fully relational -- definition of inertial systems based in the No Arbitrariness Principle, that eliminates the need for absolute inertial frames of reference in order to formulate Newtonian mechanics. This approach allows for a class of inertial systems larger than what traditionally comes out of the equivalence principle. We begin by discussing the relevance of the phenomenological map in order to relate observations and predicted observations with the mathematical structure of physical theories. After revisiting the concept of inertial frames in Classical Mechanics, we attempt to identify the phenomenological map of Special Relativity (SR) in order to establish its contact points with Classical Mechanics. SR actually inherits Lorentz' use of the ether, developed in his interpretation of Maxwell's electrodynamics. In summary, velocities in the Lorentz transformations must be \textcolor{black}{expressed from a distinguished reference frame}\textcolor{brown}{{} }if the theory is not to fall apart for being inconsistent. The consistency problem is not in the exposed part of the theory but in the supporting phenomenological map which, rather than being constructed anew, it transports concepts of Classical Mechanics by habit, without revising their validity in the context of SR.Comment: 19 pages, 1 figur

Controlling vectors: Do we need normal or post-normal science?

Is there just one science, the one we have, the given? Or on the contrary, are there several possible sciences? In the later case: which are their differences? Are they compatible? Complementary? Opposite? I will try to persuade the audience that at least three sciences can be distinguished: original blend, techno-science (normal science) and science of the postnormal age (call it transcendent science as it needs to go outside its field into the realm of decision making). I will distinguish the three at the epistemological level (arguably the deepest level) so that it may happen that what is scientific knowledge for one is not so for another.Sociedad Latinoamericana de Ecología de Vectore

Modeling Dengue Outbreaks

We introduce a dengue model (SEIR) where the human individuals are treated on an individual basis (IBM) while the mosquito population, produced by an independent model, is treated by compartments (SEI). We study the spread of epidemics by the sole action of the mosquito. Exponential, deterministic and experimental distributions for the (human) exposed period are considered in two weather scenarios, one corresponding to temperate climate and the other to tropical climate. Virus circulation, final epidemic size and duration of outbreaks are considered showing that the results present little sensitivity to the statistics followed by the exposed period provided the median of the distributions are in coincidence. Only the time between an introduced (imported) case and the appearance of the first symptomatic secondary case is sensitive to this distribution. We finally show that the IBM model introduced is precisely a realization of a compartmental model, and that at least in this case, the choice between compartmental models or IBM is only a matter of convenience.Comment: 18 pages, 6 figures, submited to Mathematical Bioscience

Pattern preserving deposition: Experimental results and modeling

In this work we discuss pattern-preserving growth during metal deposition from the vapor on micro/nano-structured metal substrates. Experimental results for Cu deposition on patterned Cu substrates show pattern preserving growth or pattern destruction depending on the incident angle. We introduce a mesoscopic 1+1 dimensional model including deposition flow (directed and isotropic), surface diffusion and shadowing effects that account for the experimental growth data. Moreover, simulations on post-deposition annealing, for high aspect-ratio patterns show departures from the predictions of the linear theory for surface diffusion.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Science, Dualities and the Phenomenological Map

We present an epistemological schema of natural sciences inspired by Peirce’s pragmaticist view, stressing the role of the phenomenological map, that connects reality and our ideas about it. The schema has a recognisable mathematical/logical structure which allows to explore some of its consequences. We show that seemingly independent principles as the requirement of reproducibility of experiments and the Principle of Sufficient Reason are both implied by the schema, as well as Popper’s concept of falsifiability. We show that the schema has some power in demarcating science by first comparing with an alternative schema advanced during the first part of the 20th century which has its roots in Hertz and has been developed by Einstein and Popper. Further, the identified differences allow us to focus in the construction of Special Relativity, showing that it uses an intuited concept of velocity that does not satisfy the requirements of reality in Peirce. While the main mathematical observation connected with this issue has been known for more than a century, it has not been investigated from an epistemological point of view. A probable reason could be that the socially dominating epistemology in physics does not encourage such line of work. We briefly discuss the relation of the abduction process presented in this work with discussions regarding “abduction” in the literature and its relation with “analogy”

A Braided View of a Knotty Story

Periodic orbits of 3-d dynamical systems admitting a Poincaré section can be described as braids. This characterisation can be transported to the Poincaré section and Poincaré map, resulting in the braid type. Information from braid types allows to estimate bounds for the topological entropy of the map while revealing detailed orbit information from the original system, such as the orbits that are necessarily present along with the given one(s) and their organisation. We review this characterisation with some examples --from a user-friendly perspective--, focusing on systems whose Poincaré section is homotopic to a disc

Stochastic model for COVID-19 in slums: interaction between biology and public policies

We present a mathematical model for the simulation of the development of an outbreak of COVID-19 in a slum area under different interventions. Instead of representing interventions as modulations of the parameters of a free running epidemic we introduce a model structure that accounts for the actions but does not assume the results. The disease is modelled in terms of the progression of viremia reported in scientific works. The emergence of symptoms in the model reflects the statistics of a nation-wide highly detailed database consisting of more than 62000 cases (about a half of the confirmed by RT-PCR tests) with recorded symptoms in Argentina. The stochastic model displays several of the characteristics of COVID-19 such as a high variability in the evolution of the outbreaks, including long periods in which they run undetected, spontaneous extinction followed by a late outbreak and unimodal as well as bimodal progressions of daily counts of cases (second waves without ad-hoc hypothesis). We show how the relation between undetected cases (including the 'asymptomatic' cases) and detected cases changes as a function of the public policies, the efficiency of the implementation and the timing with respect to the development of the outbreak. We show also that the relation between detected cases and total cases strongly depends on the implemented policies and that detected cases cannot be regarded as a measure of the outbreak, being the dependency between total cases and detected cases in general not monotonic as a function of the efficiency in the intervention method. According to the model, it is possible to control an outbreak with interventions based on the detection of symptoms only in the case when the presence of just one symptom prompts isolation and the detection efficiency reaches about 80% of the cases. Requesting two symptoms to trigger intervention can be enough to fail in the goals

On the persistence of the ether as absolute space

We analyse how the concept of the ether, playing the role of absolute space, is still present in physics. When the problem is considered in the context of classical mechanics, we show that vestiges of absolute space can be found in the standard presentation of inertial systems. We offer an alternative -- fully relational -- definition of inertial systems which not only eliminates the problem but it further shows that the equivalence principle is just a particular consequence of the No Arbitrariness Principle. In terms of Special Relativity, the non-existence of relative velocities implies a constructive contradiction (their existence is assumed in the construction). The problem is inherited from Lorentz' use of the ether, developed in his interpretation of Maxwell's electrodynamics. In summary, the velocities in the Lorentz transformations must be considered velocities relative to the ether (absolute space) if the theory is not to fall apart for being inconsistent. We discuss the relevance of the phenomenological map, and how previous works have failed to acknowledge that the consistency problem is not in the exposed part of the theory but in the supporting phenomenological map which, rather than being constructed anew, it transports concepts of classical mechanics by habit, without revising their validity in the context of Special Relativity