How and Why Fish School: An Information-theoretic Analysis of Coordinated Swimming

该基金将支持有助于提供与流体结构相互作用和集体动力学相关的新知识的研究，促进科学进步和技术进步。在没有可靠的数学模型的情况下，迫切需要在复杂的流固相互作用分析和固体间流体耦合诊断方面取得进展。工程和科学领域的关键例子包括人类发声、对阵风作出反应的高大土木结构群、用于水下传感的活性材料阵列、碳纳米管纳米片、用于流体混合和运输的纤毛阵列，以及桡足类动物的触角刚毛。该奖项支持基础研究，以填补这些知识空白，重点关注鱼类种群，其能源效率，几何复杂性和视觉吸引力几个世纪以来一直吸引着科学界和公众的兴趣。该研究涉及多个学科，包括数据驱动动力系统、实验流体力学和实验生物学。通过培训来自弱势群体的大学生，让来自弱势社区的高中生接触生物、工程和数学，并向公众推广，多学科方法在正式和非正式学习中都有势头。最近的实验结果表明，在足够大的游泳速度下，鱼群可能更喜欢以“方阵”的形式游泳，在这种形式下，没有领导者，每条鱼几乎同步地拍打尾巴。从经典的菱形到密集阵的转变挑战了目前对涡旋相互作用在鱼类鱼群中的作用的理解，这可能被其他流体动力学或视觉途径所取代。然而，目前还不可能严格测试这种可能性，因为缺乏数据驱动的技术来区分协调游泳的原因和影响。该项目将提供一种数学原则，实验基础的方法来量化动态系统集成中的信息流，通过涉及不同传播时间和物理变量的多种途径相互作用。假设驱动的、工程原理的实验将被用于发现和探索支撑协调游泳的动态结构、信息途径和能量机制。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This grant will support research that will contribute new knowledge related to fluid-structure interactions and collective dynamics, promoting the progress of science and empowering technological advancements. There is a dire need for advancements in the analysis of complex fluid-structure interactions and in the diagnostics of fluid coupling between solids, without having access to reliable mathematical models. Critical examples across engineering and science include human phonation, clusters of tall civil structures reacting to wind gusts, arrays of active materials for underwater sensing, nanomats of carbon nanotubes, arrays of cilia for fluid mixing and transport, and antennulary setal hairs of copepods. This award supports fundamental research to fill these gaps in knowledge, focusing on fish schooling, whose energy efficiency, geometric complexity, and visual allure have attracted the interest of the scientific community and general public for centuries. This research involves several disciplines bridging data-driven dynamical systems, experimental fluid mechanics, and experimental biology. The multi-disciplinary approach carries momentum in formal and informal learning, by training University students from underrepresented groups, exposing high school students from underprivileged communities to biology, engineering, and mathematics, and outreach to the general public.Recent experimental results demonstrate that at sufficiently large swimming speeds, schooling fish may prefer to swim in a "phalanx" formation, where there is no leader and every fish beats their tail almost in synchrony. The transition from the classical diamond formation to the phalanx challenges the present understanding of the role of vortex interactions in fish schooling, which might be superseded by other hydrodynamic or visual pathways. Yet, it is currently impossible to rigorously test this possibility, due to the lack of data-driven techniques to disentangle causes from effects in coordinated swimming. This project will contribute a mathematically-principled, experimentally-grounded approach to quantify information flow in ensembles of dynamical systems, interacting through multiple pathways that involve varying propagation times and physical variables. Hypothesis-driven, engineering-principled experiments will be conducted toward the discovery and exploration of dynamic structure, information pathways, and energetic mechanisms that underpin coordinated swimming.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.