Best System Approaches to Chance

2017 ◽  
Author(s):  
Wolfgang Schwarz
Keyword(s):  
Relative Frequency ◽  
David Lewis ◽  
Radioactive Elements ◽  
Physical Processes ◽  
Fundamental Physics ◽  
The One ◽  
Fundamental Physical ◽  
System Approaches ◽  
Statistical Summary ◽  
Probabilistic Theories

Certain physical processes, such as the decay of radioactive elements, seem to involve an objective, non-epistemic type of probability, often called “chance”. Best system accounts, first proposed by David Lewis, offer a Humean interpretation of chance. On this account, chance is not a fundamental physical quantity, but a kind of statistical summary of actual outcomes. The interpretation explains the close connection between chance on the one hand and relative frequency, disorder, and rational credence on the other hand. It has also proved useful in understanding probabilistic theories outside fundamental physics. On the downside, the proposal arguably fails to vindicate some philosophical preconceptions about chance.

Why Defend Humean Supervenience?

2020 ◽  
Vol 117 (7) ◽  
pp. 387-406
Author(s):  
Siegfried Jaag Siegfried Jaag ◽  
Christian Loew Christian Loew ◽  
Keyword(s):  
Level Structure ◽  
David Lewis ◽  
Physical Reality ◽  
Recent Criticism ◽  
Humean Supervenience ◽  
Intrinsic Properties ◽  
Fundamental Physics ◽  
Reductive Physicalism ◽  
In Virtue Of ◽  
Fundamental Physical

Humean Supervenience (HS) is a metaphysical model of the world according to which all truths hold in virtue of nothing but the total spatiotemporal distribution of perfectly natural, intrinsic properties. David Lewis and others have worked out many aspects of HS in great detail. A larger motivational question, however, remains unanswered: As Lewis admits, there is strong evidence from fundamental physics that HS is false. What then is the purpose of defending HS? In this paper, we argue that the philosophical merit of HS is largely independent of whether it correctly represents the world’s fundamental structure. In particular, we show that insofar as HS is an apt model of the world’s higher-level structure, it thereby provides a powerful argument for reductive physicalism and explains otherwise opaque inferential relations. Recent criticism of HS on the grounds that it misrepresents fundamental physical reality is, therefore, beside the point.

The egg steamer paradox

2021 ◽  
Vol 57 (2) ◽  
pp. 025002
Author(s):  
S Flach ◽  
S Parnovsky ◽  
A A Varlamov
Keyword(s):  
Heat Transfer ◽  
Latent Heat ◽  
Measurement Data ◽  
Transfer Mechanism ◽  
Heat Transfer Mechanism ◽  
Device Design ◽  
Physical Processes ◽  
Preparation Time ◽  
Water Reduction ◽  
The One

Abstract Why do we need to pour less water in an egg steamer to prepare more eggs to the same degree of ‘doneness’? We discuss the physical processes at work in the electric egg steamer and resolve this seeming paradox. We demonstrate that the main heat transfer mechanism from steam to egg is due to latent heat through condensation. This not only explains the paradox, but also allows us to estimate the amount of water reduction. Comparing the preparation time to the one for traditional boiling, we estimate the eggshell temperature during steaming. We also describe the device design and provide further theoretical estimates and experimental kitchen measurement data for this appealing kitchen experiment that can be easily accomplished at home.

A search for ‘frozen optical messages’ from extraterrestrial civilizations

2002 ◽  
Vol 1 (1) ◽  
pp. 71-73 ◽  
Author(s):  
R. Weinberger ◽  
H. Hartl
Keyword(s):  
Solar System ◽  
The Other ◽  
Physical Processes ◽  
High Quality ◽  
Sky Surveys ◽  
Systematic Examination ◽  
Other Hand ◽  
Celestial Bodies ◽  
The One

For a quarter of a century we have been engaged in a systematic examination of high-quality photographic (optical) sky surveys in the search for new celestial bodies of various kinds. It took about 5000 hours to cover the whole northern celestial hemisphere and half of the southern one. In total, about 12000 new objects were discovered. From the very beginning of our programme we also searched for objects (or groupings of them) of rather peculiar morphology. The motivation was to detect objects revealing exceptional physical processes, on the one hand, but also to discover constructions possibly created by advanced extraterrestrial civilizations (ETCs), on the other hand. A number of very peculiar objects were indeed found (these were mostly studied in detail later), but none of these appeared likely to be the product of alien masterminds. We may conclude that at least within about 10000–20000 light-years around the Solar system no highly advanced ETCs intend to reveal themselves through such objects.

scholarly journals Multiphoton quantum-state engineering using conditional measurements

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Omar S. Magaña-Loaiza ◽  
Roberto de J. León-Montiel ◽  
Armando Perez-Leija ◽  
Alfred B. U’Ren ◽  
Chenglong You ◽  
...  
Keyword(s):  
Quantum State ◽  
Light Sources ◽  
Physical Processes ◽  
Quantum State Engineering ◽  
Fundamental Properties ◽  
Statistical Fluctuations ◽  
Squeezed Vacuum ◽  
Vacuum States ◽  
Quantum Phenomena ◽  
Fundamental Physical

Abstract The quantum theory of electromagnetic radiation predicts characteristic statistical fluctuations for light sources as diverse as sunlight, laser radiation, and molecule fluorescence. Indeed, these underlying statistical fluctuations of light are associated with the fundamental physical processes behind their generation. In this contribution, we experimentally demonstrate that the manipulation of the quantum electromagnetic fluctuations of two-mode squeezed vacuum states leads to a family of quantum-correlated multiphoton states with tunable mean photon numbers and degree of correlation. Our technique relies on the use of conditional measurements to engineer the excitation mode of the field through the simultaneous subtraction of photons from two-mode squeezed vacuum states. The experimental generation of nonclassical multiphoton states by means of photon subtraction unveils novel mechanisms to control fundamental properties of light. As a remarkable example, we demonstrate the engineering of a quantum state of light with up to ten photons, exhibiting nearly Poissonian photon statistics, that constitutes an important step towards the generation of entangled lasers. Our technique enables a robust protocol to prepare quantum states with multiple photons in high-dimensional spaces and, as such, it constitutes a novel platform for exploring quantum phenomena in mesoscopic systems.

scholarly journals New Trends in the Simulation of Nanosplasmonic Optical D-Type Fiber Sensors

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1772 ◽  
Author(s):  
Ariel Guerreiro ◽  
Diego Felipe Santos ◽  
José Manuel Baptista
Keyword(s):  
Optical Sensors ◽  
Mode Coupling ◽  
Future Perspectives ◽  
New Materials ◽  
Numerical Techniques ◽  
Physical Processes ◽  
Fiber Sensors ◽  
Sensor Performance ◽  
Fundamental Physical ◽  
Type Fiber

This article presents a review of the numerical techniques employed in simulating plasmonic optical sensors based on metal-dielectric nanostructures, including examples, ranging from conventional D-type fiber sensors, to those based on photonic crystal D-type fibers and incorporating metamaterials, nanowires, among other new materials and components, results and applications. We start from the fundamental physical processes, such as optical and plasmonic mode coupling, and discuss the implementation of the numerical model, optical response customization and their impact in sensor performance. Finally, we examine future perspectives.

Towards a General Theory of Reduction. Part III: Cross-Categorical Reduction

Dialogue ◽  
1981 ◽  
Vol 20 (3) ◽  
pp. 496-529 ◽  
Author(s):  
C.A. Hooker
Keyword(s):  
Nervous System ◽  
Prima Facie ◽  
The Other ◽  
Mental Function ◽  
Physical Processes ◽  
Monetary System ◽  
State Association ◽  
Set Up ◽  
The One ◽  
Different Parts

Any theory of reduction that goes only so far as carried in Parts I and II ([165], [166]) does only half the job. Prima facie at least, there are cases of would-be reduction which seem torn between two conflicting intuitions. On the one side there is a strong intuition that reduction is involved, and a strongly retentive reduction at that. On the other side it seems that the concepts at one level cross-classify those at the other level, so that there is no way to identify properties at one level with those at the other. There is evidence to suggest that there will be no unique mental state/neural state association that can be set up, because, e.g., many different parts of the nervous system are all capable of taking over ‘control’ of the one mental function. And it is alleged that infinitely many, worse: indefinitely many, different bio-chemo-physical states could correspond to the economic property ‘has a monetary system of economic exchange’; and similarly for the property ‘has just won a game of tennis’. Yet one doesn't want an economic system or a game of tennis to be some ghostly addition to the actual bio-chemo-physical processes and events involved (cf. Rudner [188]). Similarly one hopes that neurophysiology allied with the rest of natural science will render human experience and behaviour explicable.

scholarly journals Simulation of Phosphorus Implantation into Silicon with a Single Parameter Electronic Stopping Power Model

1998 ◽  
Vol 09 (03) ◽  
pp. 459-470 ◽  
Author(s):  
David Cai ◽  
Charles M. Snell ◽  
Keith M. Beardmore ◽  
Niels Grønbech-Jensen
Keyword(s):  
Fine Tuning ◽  
Stopping Power ◽  
Power Model ◽  
Physical Processes ◽  
Wide Range ◽  
The One ◽  
Electron Radius ◽  
Charge Formula ◽  
Electronic Stopping Power ◽  
Dopant Profiles

We simulate dopant profiles for phosphorus implantation into silicon using a new model for electronic stopping power. In this model, the electronic stopping power is factorized into a globally averaged effective charge [Formula: see text], and a local charge density dependent electronic stopping power for a proton. There is only a single adjustable parameter in the model, namely the one electron radius [Formula: see text] which controls [Formula: see text]. By fine tuning this parameter, we obtain excellent agreement between simulated dopant profiles and the SIMS data over a wide range of energies for the channeling case. Our work provides a further example of implant species, in addition to boron and arsenic, to verify the validity of the electronic stopping power model and to illustrate its generality for studies of physical processes involving electronic stopping.

scholarly journals Memristor Equations: Incomplete Physics and Undefined Passivity/Activity

2017 ◽  
Vol 16 (04) ◽  
pp. 1771001 ◽  
Author(s):  
Kyle M. Sundqvist ◽  
David K. Ferry ◽  
Laszlo B. Kish
Keyword(s):  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Passive System ◽  
Circuit Element ◽  
Fundamental Physics ◽  
Seminal Paper ◽  
Passive Device ◽  
Fluctuation Dissipation ◽  
Passive Circuit ◽  
Fundamental Physical

In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, “The missing circuit element”. The memristor equations were originally supposed to represent a passive circuit element because, with active circuitry, arbitrary elements can be realized without limitations. Therefore, if the memristor equations do not guarantee that the circuit element can be realized by a passive system, the fundamental physics claims about the memristor as “missing circuit element” loses all its weight. The question of passivity/activity belongs to physics thus we incorporate thermodynamics into the study of this problem. We show that the memristor equations are physically incomplete regarding the problem of passivity/activity. As a consequence, the claim that the present memristor functions describe a passive device lead to unphysical results, such as violating the Second Law of thermodynamics, in infinitely large number of cases. The seminal memristor equations cannot introduce a new physical circuit element without making the model more physical such as providing the Fluctuation–Dissipation Theory of memristors.

scholarly journals Ervas daninha em pastagens: uma abordagem fitossociológica nas áreas do Ceará

Agrarian ◽  
2019 ◽  
Vol 12 (45) ◽  
pp. 279-285
Author(s):  
Josefa Maria Francieli da Silva ◽  
Hercules Gustavo Santos Sarmento ◽  
Hellen Thayse Nascimento Araújo ◽  
Alexandre Bosco de Oliveira ◽  
Lamartine Soares Cardoso de Oliveira
Keyword(s):  
Relative Frequency ◽  
Similarity Index ◽  
Cyperus Rotundus ◽  
Weed Species ◽  
Importance Value Index ◽  
Importance Value ◽  
Brachiaria Decumbens ◽  
The One ◽  
Absolute Dominance ◽  
Nicandra Physalodes

The aim of this study was to study the phytosociology of weed species in areas of pasture cultivated with Brachiaria decumbens and Cynodon sp. (Tifton 85), in Ceará State, Brazil. The square inventory methodology was used in order to assess the weed community. Weed samples were quantified and classified by family, genus and species, using books and classification keys. The classification and quantification data of species allowed to calculate the following phytosociological variables: frequency (F), relative frequency (Fr), density (D), relative density (Dr), absolute dominance (DoA), relative dominance (DoR), importance value index (IVI), and similarity index (IS). The Amaranthaceae family was the one with the greatest intensity of species in both areas, represented mainly by Alternanthera tenera colla and Amaranthus viridis. In the area cultivated with B. decumbens, Cyperus rotundus presented higher results for frequency, density and abundance. In the Tifton 85 area, Nicandra physalodes presented higher values of density and abundance. The similarity of weed populations in pasture areas was 42.11%, with four species common to both areas.

scholarly journals On the Local Distribution of Certain Illinois Fishes:

1907 ◽  
Vol 7 (1-10) ◽  
pp. 273-303 ◽  
Author(s):  
S. A. Forbes
Keyword(s):  
Relative Frequency ◽  
The Other ◽  
Local Distribution ◽  
Constituent Species ◽  
Ecological Relationship ◽  
The One

This paper is thus to be taken as a contribution to an answer to the following questions: What Illinois fishes are habitually found in each others' society,and what is the relative frequency of their associations? How are Illinois fishes grouped and distributed according to location and situation, and in each ecological assemblage so formed what is the proportionate representation of its various constituent species? How far are the two classes of data^ those of associative affiliation and of ecological relationship, comparable, and to what extent may the one be used to explain the other?

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