In statistical mechanics, nearly all the textbooks say that the volume of the smallest cell in the phase space of a N-particle system is h[itex]^{rN}[/itex] where h is the Planck Constant, r is the degree of freedom.(adsbygoogle = window.adsbygoogle || []).push({});

Also these books say that this comes from the uncertainty principle.

However, the uncertainty principle is ΔxΔpx[itex]\geqℏ/2[/itex] .

So why they take h instead of ℏ/2 in calculating the volume?

Many thanks!

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# Question about the uncertainty principle and unit cell in phase space

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