How can we be sure of Planck’s constant when we have never measured anything to that accuracy?

Question

Any constant in physics or chemistry comes from experimental design and consistency in measurements. For example, if you divide multiple of pressure and volume with the multiple of moles and temperature, you will get the constant R for any ideal gas.

However, given how small planck’s constant is, how can we assume its accuracy?

In: Physics

Answer 1

The value of Planck’s constant was initially based on a statistical model, that was supposed to explain the emission of light by hot bodies. Planck never measured a single quantum of light, but his model was the only one to make sense when measuring how the light spectrums looked like.