长寿的巨型数量波动在一群群的颗粒状体中
Vijay Narayan1, Sriram Ramaswamy, Narayanan Menon
1Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India. vj@physics.iisc.ernet.in
Science (New York, N.Y.)
|July 7, 2007
概括
生物系统表现出自发的秩序,与平衡系统不同. 这项研究揭示了宏观杆的巨大数量波动和长期不均性,证明了没有直接通信的群体行为.
科学领域:
- 物理 物理学 物理
- 软物质物理学 软物质物理学
- 活动物质物理学 活动物质物理学
背景情况:
- 像鸟群或细菌群这样的生物系统表现出自发的定向秩序.
- 这种系统不同于平衡系统,平衡系统也表现出液晶秩序.
- 了解生活物质集体运动背后的机制至关重要.
研究的目的:
- 研究具有自发秩序的生物和具有类似秩序的平衡系统之间的差异.
- 在一个简化的模型系统中探索集体运动和大规模不均性的出现.
- 为了确定在没有远程通信的系统中是否会出现集群行为.
主要方法:
- 使用一个液化单层的宏观棒.
- 将系统限制在阴性液晶阶段.
- 观测和量化粒子数的波动及其时间衰变.
主要成果:
- 观察到巨大的数值波动,其中标准偏差与平均值线性增长.
- 这些波动偏离了中央极限定理的预测.
- 波动是长期存在的,随着时间的推移对数分解.
结论:
- 在粒子仅通过接触相互作用的系统中,可以出现集群和连贯运动.
- 即使没有直接的粒子通信,大规模的不均性也是可能的.
- 这些发现表明,基于接触的相互作用可以在活性物质中驱动复杂的集体行为.
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