

How to Measure Planck’s Constant Using Lego - andyjohnson0
http://www.technologyreview.com/view/533401/how-to-measure-plancks-constant-using-lego/

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quarterwave
Nice trick, to cancel the e^2 from (h/e)^2 and h/e^2 to give h, and do it a
way accessible to a basic laboratory.

The interesting thing about h/e^2 as Hall resistance is that it's an off-
diagonal term in the Onsager matrix, while here it is used to balance a
diagonal term i.e; work.

Equally nice is to consume Newton's gravitational constant in g, the
acceleration due to gravity, because somewhere the mass needs to come out, and
there is no mass in the Maxwell equations. The Planck voltage sqrt(G _e^2
/(h_c^5)) is very small (compared with electrochemical potentials): 3.3e-29
Volts.

