# Talk:Brownian motion

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## make page (in 2025): Brownian battery

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• Physicists build circuit that generates clean, limitless power from graphene

by University of Arkansas - phys.org — Preceding unsigned comment added by 2a02:587:410b:c290:5918:f010:9a03:72e9 (talk) 23:10, 3 October 2020 (UTC)

## Statistical mechanics theories

### Einstein's theory

In the subsection Brownian_motion#Einstein's_theory, at the first line of the Taylor Series expansion, we have the following equality:

${\displaystyle \rho (x,t)+\tau {\frac {\partial \rho (x)}{\partial t}}+\cdots =\rho (x,t+\tau )=\int _{-\infty }^{\infty }\rho (x-\Delta ,t)\cdot \varphi (\Delta )\,\mathrm {d} \Delta =\mathbb {E} _{\Delta }[\rho (x-\Delta ,t)]}$

On the right hand side, why do we have ${\displaystyle \rho (x-\Delta ,t)}$ insted of ${\displaystyle \rho (x+\Delta ,t)}$?, since Einstein himself derived the Diffusion Equation from[1] ${\displaystyle f(x,t+\tau )=\int _{-\infty }^{\infty }f(x+\Delta ,t)\cdot \varphi (\Delta )\mathrm {d} \Delta }$.

Zaphodxvii (talk) 04:31, 31 December 2020 (UTC)

References

1. ^ Einstein, Albert (1956) [1926]. Investigations on the Theory of the Brownian Movement (PDF). Dover Publications. Retrieved 2013-12-25.

## UiawsbdNicoDude

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## Article issues and classification

Greetings. The article has been tagged since 2012 with "citation needed". The B-class criteria (#1) states, The article is suitably referenced, with inline citations. It has reliable sources, and any important or controversial material which is likely to be challenged is cited.
There is also a "needing clarification" tag since April 2010 and "too technical" since June 2011. Criteria #4 states, The article is reasonably well-written and #6 states, The article presents its content in an appropriately understandable way.
There are many unsourced paragraphs and the article fails the B-class assessment. -- Otr500 (talk) 08:07, 27 February 2023 (UTC)