### Abstract

Original language | English |
---|---|

Pages (from-to) | 113-119 |

Number of pages | 7 |

Journal | American Journal of Physics |

Volume | 69 |

Issue number | 2 |

DOIs | |

Publication status | Published - Feb 2001 |

### Fingerprint

### Keywords

- particle fluctuations
- classical mechanics
- classical statistical mechanics
- conservation laws
- elastic collisions

### Cite this

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*American Journal of Physics*, vol. 69, no. 2, pp. 113-119. https://doi.org/10.1119/1.1289211

**Dissipation, fluctuations and conservation laws.** / Grassia, Paul.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Dissipation, fluctuations and conservation laws

AU - Grassia, Paul

PY - 2001/2

Y1 - 2001/2

N2 - A large particle moves through a sea of small particles. On the microscale, all particle collisions are elastic. However, on the macroscale, where only the large particle is properly resolved, dissipative forces and fluctuating random forces are observed. These forces are connected by a fluctuation–dissipationtheorem proved in two different ways, first via statistical mechanics, and second from fundamental classical mechanical principles of momentum and energy conservation. The novel classical mechanics proof elucidates the relation between micro- and macroscale behaviors, and offers new insights into the physics behind the fluctuation–dissipation result.

AB - A large particle moves through a sea of small particles. On the microscale, all particle collisions are elastic. However, on the macroscale, where only the large particle is properly resolved, dissipative forces and fluctuating random forces are observed. These forces are connected by a fluctuation–dissipationtheorem proved in two different ways, first via statistical mechanics, and second from fundamental classical mechanical principles of momentum and energy conservation. The novel classical mechanics proof elucidates the relation between micro- and macroscale behaviors, and offers new insights into the physics behind the fluctuation–dissipation result.

KW - particle fluctuations

KW - classical mechanics

KW - classical statistical mechanics

KW - conservation laws

KW - elastic collisions

UR - http://scitation.aip.org/content/aapt/journal/ajp

U2 - 10.1119/1.1289211

DO - 10.1119/1.1289211

M3 - Article

VL - 69

SP - 113

EP - 119

JO - American Journal of Physics

JF - American Journal of Physics

SN - 0002-9505

IS - 2

ER -