Information stored in Faraday waves: the origin of a path memory

2011 ◽  
Vol 674 ◽  
pp. 433-463 ◽  
Author(s):  
ANTONIN EDDI ◽  
ERIC SULTAN ◽  
JULIEN MOUKHTAR ◽  
EMMANUEL FORT ◽  
MAURICE ROSSI ◽  
...  
Keyword(s):  
Wave Field ◽  
Travelling Wave ◽  
Linear Superposition ◽  
The Past ◽  
Droplet Collisions ◽  
Pilot Wave ◽  
Faraday Instability ◽  
Localized Mode ◽  
Particle Association ◽  
The Waves

On a vertically vibrating fluid interface, a droplet can remain bouncing indefinitely. When approaching the Faraday instability onset, the droplet couples to the wave it generates and starts propagating horizontally. The resulting wave–particle association, called a walker, was shown previously to have remarkable dynamical properties, reminiscent of quantum behaviours. In the present article, the nature of a walker's wave field is investigated experimentally, numerically and theoretically. It is shown to result from the superposition of waves emitted by the droplet collisions with the interface. A single impact is studied experimentally and in a fluid mechanics theoretical approach. It is shown that each shock emits a radial travelling wave, leaving behind a localized mode of slowly decaying Faraday standing waves. As it moves, the walker keeps generating waves and the global structure of the wave field results from the linear superposition of the waves generated along the recent trajectory. For rectilinear trajectories, this results in a Fresnel interference pattern of the global wave field. Since the droplet moves due to its interaction with the distorted interface, this means that it is guided by a pilot wave that contains a path memory. Through this wave-mediated memory, the past as well as the environment determines the walker's present motion.

Biography and Autobiography

2021 ◽  
pp. 211-224
Author(s):  
Laura Marcus
Keyword(s):  
Life Writing ◽  
Crucial Aspect ◽  
Reading And Writing ◽  
To The Lighthouse ◽  
Victorian Era ◽  
The Past ◽  
Cultural Milieu ◽  
The Waves ◽  
Jacob's Room

This chapter explores the centrality of biography and autobiography to Woolf’s reading and writing life, and to her cultural milieu, in which experiments in life-writing were a crucial aspect of the modernist reaction against the Victorian era. It examines Woolf’s deep engagement in her fiction with life-writing forms, from the bildungsroman of The Voyage Out to the play with conventional biographical forms of Jacob’s Room, Orlando, The Waves, and Flush and the autobiographical foundations of To the Lighthouse. It also examines her biography of Roger Fry, and her own experiment in memoir-writing, the posthumously published ‘A Sketch of the Past’, in the context of concerns with the nature of memory, identity, and sexuality.

scholarly journals Periodicity: Interpreting Waves of Information in Osundare’s Harvestcall

2017 ◽  
Vol 10 ◽  
pp. 42-70
Author(s):  
Taofeek Olaiwola Dalamu
Keyword(s):  
Time Frame ◽  
The Past ◽  
Systemic Analysis ◽  
Literary Device ◽  
Different Shapes ◽  
Analytical Tools ◽  
The Waves

The study investigated the waves of information of Osundara’s Harvestcall to show textual movements as layered by the poet. To achieve that objective, the poem of about 76 lines was collapsed into 44 clauses as a tradition that paves a way for systemic analysis of texts in different shapes, sizes and constructs. Halliday’s Theme and Rheme served as analytical tools that processed the text after which the investigation utilized tables and graphs as indicators of waves of information of Harvestcall. The analysis reveals three separate waves of the text, namely: (i) sectional organization – perceives Sections I, II and III are the Theme while Section IV is the Rheme; (ii) clause constructs – demonstrates multiple Themes that flow to rhematic structures; and (iii) time frame exposition – espouses the past farming commitment as Theme and its current neglect as Rheme. In addition, observation shows waves interference. That is, the switching of Theme 2 and Subject Theme in Sections I, II and III for Subject Theme and Theme 2 respectively in Section IV. As linguistic concepts can reveal so much meanings of a literary device, the study suggests their applications across the board of genres of literature.

scholarly journals How well do we know the rotation curve of our Galaxy?

1985 ◽  
Vol 106 ◽  
pp. 107-108
Author(s):  
Paris Pişmiş
Keyword(s):  
Velocity Field ◽  
Rotation Curve ◽  
Spiral Galaxies ◽  
Spiral Structure ◽  
Smooth Curve ◽  
Velocity Fields ◽  
Rotation Curves ◽  
The Past ◽  
Different Populations ◽  
The Waves

The existence of variations from a smooth curve, in the form of waves, in the rotation curves of galaxies was pointed out earlier, and an interpretation was proposed based on the argument that the waves were the manifestation of the coexistence of different populations in a galaxy (see for example PişLmiş 1965, 1974). Observations in the past few years have shown that “undulations” in the rotation curve of spiral galaxies are rather common phenomena; maxima and minima occur roughly at arm and interarm regions, respectively. The velocity fields of the majority of the 23 galaxies compiled by Bosma (1978) exhibit well-defined waves. In particular the velocity field in the 21-cm HI line of M81 by Visser shows clearly the correlation of the waves with the spiral structure.

Measuring shear wave velocity, Vs, of a hidden layer: an application to soil improvement under roads

2015 ◽  
Vol 52 (6) ◽  
pp. 721-731 ◽  
Author(s):  
Francesco Mulargia ◽  
Silvia Castellaro ◽  
Gianluca Vinco
Keyword(s):  
Seismic Source ◽  
Soil Improvement ◽  
Rigid Surface ◽  
Specific Kind ◽  
Viable Option ◽  
The Past ◽  
Alternative Approach ◽  
Hidden Layer ◽  
The Waves ◽  
Soft Interface

In a number of practical cases, a typical one being the investigation of the subsoil properties below roads or foundations, one faces the problem of measuring the elastic properties of a geological layer (here called “hidden layer”) underlying a more compact and rigid surface layer. In such cases, the effectiveness of common surface seismic methods is poor for different reasons, but mostly linked to the reflection–transmission properties of the waves at a stiff-to-soft interface. Borehole methods are more efficient, but expensive and only provide vertical information at certain points. Attempts carried out in the past to characterize the hidden layer properties through surface seismic techniques consisted in placing the seismic source on the surface alongside, but off the stiff artificial layer (road or foundation). An alternative approach is presented based on placing the seismic source just below the stiff artificial layer. In cases where soil improvement–compaction are carried out through injection of expanding resins, then the hidden layer can be easily reached via the injecting tools and in some cases (e.g., urban settings characterized by laterally continuous artificial layers or roads constructed on embankments) this can be the only viable option. The results obtained from this approach using a number of practical cases where roads affected by differential sinking have later been compacted will be presented. The average soil improvement that can be achieved with the specific kind of expanding resin used in this study is then quantified.

Observations and simulations of foreshock waves during magnetic clouds

2020 ◽  
Author(s):  
Lucile Turc ◽  
Owen Roberts ◽  
Martin Archer ◽  
Minna Palmroth ◽  
Markus Battarbee ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Numerical Simulations ◽  
Wave Field ◽  
Geomagnetic Storms ◽  
Wave Activity ◽  
Bow Shock ◽  
Magnetic Clouds ◽  
Direction Parallel ◽  
High Magnetic Field Strength ◽  
The Waves

<p>The foreshock is a region of intense wave activity, situated upstream of the quasi-parallel sector of the terrestrial bow shock. The most common type of waves in the Earth's ion foreshock are quasi-monochromatic fast magnetosonic waves with a period of about 30 s. In this study, we investigate how the foreshock wave field is modified when magnetic clouds, a subset of coronal mass ejections driving the most intense geomagnetic storms, interact with near-Earth space. Using observations from the Cluster constellation, we find that the average period of the fast magnetosonic waves is significantly shorter than the typical 30 s during magnetic clouds, due to the high magnetic field strength inside those structures, consistent with previous works. We also show that the quasi-monochromatic waves are replaced by a superposition of waves at different frequencies. Numerical simulations performed with the hybrid-Vlasov model Vlasiator consistently show that an enhanced upstream magnetic field results in less monochromatic wave activity in the foreshock. The global view of the foreshock wave field provided by the simulation further reveals that the waves are significantly smaller during magnetic clouds, both in the direction parallel and perpendicular to the wave vector. We estimate the transverse extent of the waves using a multi-spacecraft analysis technique and find a good agreement between the numerical simulations and the spacecraft measurements. This suggests that the foreshock wave field is structured over smaller scales during magnetic clouds. These modifications of the foreshock wave properties are likely to affect the regions downstream - the bow shock, the magnetosheath and possibly the magnetosphere - as foreshock waves are advected earthward by the solar wind.</p>

Lee waves in stratified flows with simple harmonic time dependence

1975 ◽  
Vol 67 (4) ◽  
pp. 705-722 ◽  
Author(s):  
T. H. Bell
Keyword(s):  
Wave Field ◽  
Fundamental Frequency ◽  
Internal Gravity Wave ◽  
Stratified Flows ◽  
Wave Problem ◽  
Static Approximation ◽  
Lee Waves ◽  
Lee Wave ◽  
Harmonic Flow ◽  
The Waves

The process of internal gravity wave generation by the simple harmonic flow (U=U0, cos ω0t) of a stably stratified fluid (Brunt–Väisälä frequencyN) over an obstacle is investigated in some detail. Attention is primarily directed to the behaviour of the solution in various limiting cases, and to estimating the flux of energy into the internal wave field. In general, waves are generated not only at the fundamental frequency ω0, but also at all of its harmonics. But, for values of ω0/Ngreater than about one half, the waves of fundamental frequency are dominant. For values of ω0/N, less than about one half, the quasi-static approximation, in which the problem is considered as a slowly-varying version of the classical lee wave problem, is found to provide a viable estimate for the wave field. The general solution is found to compare favourably with the limited available experimental data.

Faraday instability in floating liquid lenses: the spontaneous mutual adaptation due to radiation pressure

2013 ◽  
Vol 725 ◽  
pp. 402-427 ◽  
Author(s):  
G. Pucci ◽  
M. Ben Amar ◽  
Y. Couder
Keyword(s):  
Wave Field ◽  
Radiation Pressure ◽  
Open Space ◽  
Steady Regime ◽  
Liquid Lenses ◽  
Self Organized ◽  
Mutual Adaptation ◽  
Faraday Instability ◽  
Fixed Boundaries ◽  
Intermediate Situation

AbstractFluid dynamics instabilities are usually investigated in two types of situations, either confined in cells with fixed boundaries, or free to grow in open space. In this article we study the Faraday instability triggered in a floating liquid lens. This is an intermediate situation in which a hydrodynamical instability develops in a domain with flexible boundaries. The instability is observed to be initially disordered with fluctuations of both the wave field and the lens boundaries. However, a slow dynamics takes place, leading to a mutual adaptation so that a steady regime is reached with a stable wave field in a stable lens contour. The most recurrent equilibrium lens shape is elongated with the Faraday wave vector along the main axis. In this self-organized situation an equilibrium is reached between the radiation pressure exerted by Faraday waves on the borders and their capillary response. The elongated shape is obtained theoretically as the exact solution of a Riccati equation with a unique control parameter and compared with the experiment.

Generation of a coherent superposition of a travelling wave field

2007 ◽  
Vol 54 (13-15) ◽  
pp. 1999-2008 ◽  
Author(s):  
M. S. Kim ◽  
M. Paternostro
Keyword(s):  
Wave Field ◽  
Travelling Wave ◽  
Coherent Superposition

scholarly journals NATURAL WAVE TRAINS: DESCRIPTION AND REPRODUCTION

1978 ◽  
Vol 1 (16) ◽  
pp. 16 ◽  
Author(s):  
H. Lundgren ◽  
S.E. Sand
Keyword(s):  
Numerical Models ◽  
Wave Train ◽  
Three Dimensional ◽  
Correct Description ◽  
Linear Superposition ◽  
Natural Wave ◽  
Wave Trains ◽  
Steep Waves ◽  
Deterministic Description ◽  
The Waves

In many applications there is a great need for a correct description of the natural, irregular three-dimensional sea and its reproduction in physical and numerical models. Because of the tremendous difficulties inherent in the nonlinearities, the science of coastal engineering is still very far from this ultimate goal. Indeed, the scope of this paper is comparatively very modest: To describe and reproduce natural, irregular two-dimensional waves, i.e. waves propagating in one direction in a flume. In addition, this scope is fulfilled only by assuming linear superposition of Fourier terms. As opposed to the usual spectral description, the deterministic description presented here does not eliminate the phase information in the wave train recorded. Because of the nonlinearities, however, the linear deterministic description invariably degenerates with the distance travelled by the waves. It appears though from the present paper that the degeneration is fairly slow even for rather steep waves.

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