Re:How to Measure Planck’s Constant Using Lego
by quarterwave on Sunday January 04, 2015 @09:15PM
(#8836784)
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(Ge^2/(hc^5)) is very small (compared with electrochemical potentials): 3.3e-29 Volts.
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(Ge^2/(hc^5)) is very small (compared with electrochemical potentials): 3.3e-29 Volts.