On Brownian motion in ideal gas and related principles

TL;DR

This paper explores the nature of Brownian motion in an ideal gas, emphasizing the distinction between theoretical models and real gases with scale-invariant fluctuations in kinetic properties.

Contribution

It provides a conceptual analysis of Brownian motion in ideal gases, highlighting the differences between simplified models and real systems with 1/f fluctuations.

Findings

Brownian motion in ideal gases is linked to kinetic fluctuations.

Real gases exhibit scale-invariant (1/f) fluctuations in kinetic characteristics.

The study bridges theoretical models and actual gas behavior.

Abstract

Brownian motion of particle interacting with atoms of ideal gas is discussed as a key problem of kinetics lying at the border between ``dead'' systems like the Lorentz gas or formal constructs of conceptual Boltzmannian kinetics and actual ``alive'' systems like mere gas possessing scaleless (1/f) fluctuations in their kinetic characteristics (e.g. in diffusuvity and mobility of the ``Brownian particle'').