Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

First Law: Particles in Two-dimensional Equilibrium

First Law: Particles in Two-dimensional Equilibrium

Recall that a particle in equilibrium is one for which the external forces are balanced. Static equilibrium involves objects at rest, and dynamic equilibrium involves objects in motion without acceleration; but it is important to remember that these conditions are relative. For instance, an object may be at rest when viewed from one frame of reference, but that same object would appear to be in motion when viewed by someone moving at a constant velocity.
Newton's first law tells us about the...

First Law: Particles in One-dimensional Equilibrium

First Law: Particles in One-dimensional Equilibrium

Newton's first law of motion states that a body at rest remains at rest, or if in motion, remains in motion at constant velocity, unless acted on by a net external force. It also states that there must be a cause for any change in velocity (a change in either magnitude or direction) to occur. This cause is a net external force. For example, consider what happens to an object sliding along a rough horizontal surface. The object quickly grinds to a halt, due to the net force of friction. If we...

Equation of Motion: Center of Mass

Equation of Motion: Center of Mass

The equation of motion for a single particle can be expanded to encompass a system of particles consisting of n particles. For any arbitrarily chosen particle within this system, the net force acting upon it is the aggregate of both internal and external forces. Extending this principle to all particles within the system results in the equation of motion for the entire assembly.
Internal forces between any pair of particles manifest as collinear pairs of equal magnitude but opposite directions,...

Principle of Linear Impulse and Momentum for a System of Particles

Principle of Linear Impulse and Momentum for a System of Particles

In the context of a system of particles moving relative to an inertial frame of reference, the equation of motion is a crucial tool for understanding the dynamics of the system. This equation, which accounts for external forces acting on each particle, plays a fundamental role in describing the system's behavior.
Notably, internal forces between particles, occurring in equal and opposite collinear pairs, cancel out and are not part of the equation of motion. This exclusion simplifies the...

Principle of Linear Impulse and Momentum for a Single Particle

Principle of Linear Impulse and Momentum for a Single Particle

Linear momentum is a fundamental concept in physics that describes the motion of an object. It is a vector quantity, having a magnitude equal to the product of its mass and its velocity, and direction along the object's velocity. On the other hand, linear impulse, also known as momentum impulse, is a concept in physics related to the change in the linear momentum of an object. Impulse is a vector quantity defined as the product of force and the time over which the force is applied.
Delving into...

Equilibrium Conditions for a Particle

Equilibrium Conditions for a Particle

When an object is in equilibrium, it is either at rest or moving with a constant velocity. There are two types of equilibrium: static and dynamic. Static equilibrium occurs when an object is at rest, while dynamic equilibrium occurs when an object is moving with a constant velocity. In both cases, there must be a balance of forces acting on the object.
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Order-disorder transition in incompressible polar active fluids with an easy axis.

Physical review. E·2026

Same author

Only the ambidextrous can flock: Two-dimensional chiral Malthusian flocks, time cholesterics, and the Kardar-Parisi-Zhang equation.

Physical review. E·2026

Same author

Optimizing scheduling in dual-pulse nucleoside labeling experiments for cell-cycle analysis.

Biophysical journal·2026

Same author

The synaptonemal complex aligns meiotic chromosomes by wetting.

Science advances·2025

Same author

New Universality Class Describes Vicsek's Flocking Phase in Physical Dimensions.

Physical review letters·2024

Same author

The synaptonemal complex aligns meiotic chromosomes by wetting.

bioRxiv : the preprint server for biology·2024

Search research articles

Related Experiment Video

Updated: Jun 14, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

Published on: December 4, 2017

Fluctuation-induced collective motion: a single-particle density analysis.

¹Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Str 38, 01187 Dresden, Germany. cflee@pks.mpg.de

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics

|April 7, 2010

Summary

Collective motion in noisy self-propelled particles emerges above a density threshold. Perturbation profiles significantly influence this threshold, with localized, large-magnitude perturbations indicating collective motion onset. High particle speed also promotes collective motion.

More Related Videos

Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions

Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions

Published on: February 22, 2018

Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures

Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures

Published on: May 20, 2014

Related Experiment Videos

Last Updated: Jun 14, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

Published on: December 4, 2017

Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions

Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions

Published on: February 22, 2018

Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures

Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures

Published on: May 20, 2014

Area of Science:

Physics
Statistical Mechanics
Complex Systems

Background:

Noisy self-propelled particles exhibit collective motion above a critical density.
Interactions favoring directional alignment are key to emergent collective behavior.
The influence of initial perturbations on collective motion onset is not fully understood.

Purpose of the Study:

To investigate how the spatial profile of angular perturbations affects the threshold for collective motion in noisy self-propelled particles.
To determine if localized, large-magnitude perturbations can act as indicators for the onset of collective motion.
To analyze the role of particle speed in promoting collective motion.

Main Methods:

Mean-field analysis
Linear stability analysis
Perturbative analysis
Numerical simulations
Approximated Fokker-Planck equation

Main Results:

The threshold for collective motion is dependent on the spatial profile of angular perturbations.
Large-magnitude, spatially localized perturbations are amplified and signal the onset of collective motion.
Increased particle speed enhances the likelihood and prominence of collective motion.

Conclusions:

The spatial characteristics of initial perturbations are crucial factors in initiating collective motion.
Localized perturbations can serve as predictive indicators for collective motion in these systems.
Particle speed is a significant parameter that facilitates the emergence of collective behavior.