Boundary Interactions in Pilot-Wave Hydrodynamics

导波流体动力学中的边界相互作用

• 批准号: 1727565
• 负责人: John Bush
• 金额: $ 44.99万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1727565&HistoricalAwards=false
• 关键词: Boundary; Interactions; Pilot; Wave; Hydrodynamics

This project is an experimental and theoretical investigation of the "walking droplet" system, in which a millimeter-size droplet bounces across a vibrating fluid bath, propelled by a resonant interaction with the waves created when it strikes the fluid surface. The walking droplet exhibits several features previously thought unique to the microscopic quantum realm. The outcome of this project will be a critical assessment of the potential and limitations of the walking droplet system as an analog for microscopic behavior. Although the walking droplet system was discovered only a decade ago, a similar conception for the motion of microscopic quantum particles was formulated in the 1920s by pioneering physicist Louis de Broglie. De Broglie envisioned microscopic particles moving in resonance with what he called a "pilot wave." Working from this conception, de Broglie deduced a number of equations that became the cornerstones of modern quantum theory, and correctly predicted the phenomenon of electron diffraction, for which he received the Nobel Prize. Despite this early success, the pilot wave concept was overshadowed by the viewpoint that the statistical predictions of quantum mechanics stand alone as a complete description of physical reality on the microscopic scale, with no role for any additional physical structure. This project revisits these competing models, and asks whether chaotic pilot-wave dynamics, of the form conceived by de Broglie and now realized in the walking droplet system might plausibly underlie quantum statistics. If the answer is yes, then the prevailing view of the microscopic realm will require drastic revision, with deep implications for the philosophy of science. The PIs have designed a walking droplet apparatus, controlled by a free smartphone app, which can be built for less than $60. The PIs have used the walking droplet experiment for a variety of science outreach activities. This project will both question and inform the philosophical foundations of modern physics. The bouncing drop system, characterized by a resonant interaction between a particle and its guiding wave, is a rich new dynamical system that extends the range of classical systems to include features previously thought to be exclusive to the microscopic realm. It is, moreover, the first macroscopic realization of a pilot-wave dynamics of the form that was postured in the 1920s by Louis de Broglie, who, in his double-solution theory, envisaged microscopic quantum particles moving in resonance with a guiding wave. This study builds upon prior work that has yielded both the most refined bouncing-drop experimental system in operation and the most sophisticated theoretical models. Together the theory and experiments provide predictive power for the dynamics and stability of this hydrodynamic pilot-wave system. This project will apply these refined experimental and theoretical tools to revisit key hydrodynamic quantum analog systems involving boundary interactions, including motion in confined geometries and single-particle diffraction and interference. The project will also examine several new analog systems, including refraction of walkers across discrete steps, where a modified Snell's Law is obeyed, and scattering from circular obstacles, where a property akin to electromagnetic self-induction arises. Hydrodynamic analogs of the quantum mirage, Kapitza-Dirac effect, and Bragg scattering will also be explored. This class of problems will lead to a better understanding of pilot-wave hydrodynamics, and add to the growing list of hydrodynamic quantum analogs. In providing the opportunity to observe and understand pilot-wave dynamics on a macroscopic scale, the bouncing droplet system invites a critical revisitation of de Broglie's pilot-wave mechanics, and an examination of its viability as the basis for a realist quantum dynamics.

该项目是对“行走液滴”系统的实验和理论研究，在该系统中，毫米大小的液滴在与撞击流体表面时产生的波的共振相互作用的推动下，在振动的流体浴中弹跳。行走的水滴表现出一些以前被认为是微观量子领域独有的特征。该项目的成果将是对步行液滴系统作为微观行为模拟的潜力和局限性进行严格评估。尽管步行液滴系统仅在十年前被发现，但物理学先驱路易斯·德布罗意 (Louis de Broglie) 在 20 年代提出了关于微观量子粒子运动的类似概念。 德布罗意设想微观粒子与他所谓的“导频波”共振。从这个概念出发，德布罗意推导出了许多方程，这些方程成为现代量子理论的基石，并正确预测了电子衍射现象，并因此获得了诺贝尔奖。尽管取得了早期的成功，但导波概念被以下观点所掩盖：量子力学的统计预测是对微观尺度上物理现实的完整描述，没有任何附加物理结构的作用。该项目重新审视了这些相互竞争的模型，并询问德布罗意设想的混沌导波动力学形式（目前在行走液滴系统中实现）是否可能成为量子统计的基础。如果答案是肯定的，那么微观领域的流行观点将需要进行彻底的修改，这对科学哲学具有深远的影响。 PI 设计了一种步行式液滴装置，由免费的智能手机应用程序控制，其制造成本不到 60 美元。 PI 将步行液滴实验用于各种科学推广活动。该项目将对现代物理学的哲学基础提出质疑并提供信息。弹跳水滴系统的特点是粒子与其引导波之间的共振相互作用，是一种丰富的新动力系统，它扩展了经典系统的范围，包括以前被认为是微观领域独有的特征。此外，这是路易斯·德布罗意在 20 年代提出的导波动力学形式的首次宏观实现，他在他的双解理论中设想了微观量子粒子与导波共振运动。这项研究建立在先前工作的基础上，这些工作产生了运行中最完善的弹跳滴实验系统和最复杂的理论模型。理论和实验共同为该水动力导波系统的动力学和稳定性提供了预测能力。该项目将应用这些完善的实验和理论工具来重新审视涉及边界相互作用的关键流体动力学量子模拟系统，包括受限几何形状中的运动以及单粒子衍射和干涉。该项目还将研究几个新的模拟系统，包括步行者跨越离散台阶的折射（遵守修改后的斯涅尔定律），以及圆形障碍物的散射（出现类似于电磁自感应的特性）。量子海市蜃楼、卡皮查-狄拉克效应和布拉格散射的流体动力学类似物也将被探索。这类问题将有助于更好地理解导波流体动力学，并添加到不断增长的流体动力学量子类似物列表中。为了提供在宏观尺度上观察和理解引导波动力学的机会，弹跳液滴系统引发了对德布罗意的引导波力学的批判性重新审视，并检验了其作为现实主义量子动力学基础的可行性。

项目成果

Introduction to focus issue on hydrodynamic quantum analogs.

介绍流体动力学量子类似物的焦点问题。

• DOI: 10.1063/1.5055383
• 发表时间: 2018
• 期刊: Chaos (Woodbury, N.Y.)
• 作者: Bush JWM

Collective vibrations of confined levitating droplets

• DOI: 10.1103/physrevfluids.5.083601
• 发表时间: 2020-01
• 期刊: arXiv: Soft Condensed Matter
• 作者: Stuart A. J. Thomson;M. Couchman;J. M. Bush

Classical pilot-wave dynamics: The free particle

• DOI: 10.1063/5.0039975
• 发表时间: 2021-03-01
• 期刊: CHAOS
• 影响因子: 2.9
• 作者: Durey, Matthew;Bush, John W. M.
• 通讯作者: Bush, John W. M.

Walking droplets interacting with single and double slits

行走的水滴与单缝和双缝相互作用

• DOI: 10.1017/jfm.2017.790
• 发表时间: 2018
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Pucci, Giuseppe;Harris, Daniel M.;Faria, Luiz M.;Bush, John W.
• 通讯作者: Bush, John W.

Hydrodynamic analog of particle trapping with the Talbot effect

• DOI: 10.1103/physrevfluids.2.103602
• 发表时间: 2017-10
• 作者: N. Sungar;Lucas D Tambasco;G. Pucci;P. Sáenz;J. M. Bush