  The most striking result here is that the notion of Planckian dissipation is
also applicable to the $c$-axis resistivity of the high temperature cuprate
superconductors, and to my knowledge this aspect has not been previously
addressed. The derivation involves Kubo formula and does not require any
mechanism beyond a non-Fermi liquid assumption. The $c$-axis resistivity, in
its essential aspects, is discussed in the context of quantum critical point.
Finally, I consider a zero temperature problem with one of its spatial
dimensions compactified. The warning is that this compatification scale at the
quantum critical point behaves similarly to the finite temperature problem, but
obviously being at zero temperature there is no dissipation.
