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[0] https://en.wikipedia.org/wiki/SI_base_unit#Seven_SI_base_uni...
[1] https://en.wikipedia.org/wiki/Proposed_redefinition_of_SI_ba...
>Based on 16 months' worth of measurements, it calculated Planck's constant to be 6.626069934 x 10−34 kg∙m2/s.
They define it based on Planck's constant, so the results also depends on the definition of meter and seconds if I understand it correctly. Would it have been possible to define it as the weight of N amount of electrons (assuming all electrons have the exact same weight under all circumstances) or another fundamental particle? EDIT: it would be the weight of 9.10938356e31 electrons at rest
>For electrons or electron holes in a solid, the effective mass is usually stated in units of the rest mass of an electron, me (9.11×10−31 kg). In these units it is usually in the range 0.01 to 10, but can also be lower or higher—for example, reaching 1,000 in exotic heavy fermion materials, or anywhere from zero to infinity (depending on definition) in graphene. <
They define it based on Planck's constant, so the results also depends on the definition of meter and seconds if I understand it correctly. Would it have been possible to define it as the weight of N amount of electrons (assuming all electrons have the exact same weight under all circumstances) or another fundamental particle? EDIT: it would be the weight of 9.10938356e31 electrons at rest
One way has been by counting silicon atoms in a nearly-perfect spherical crystal. http://aip.scitation.org/doi/full/10.1063/1.4921240
It's a little ironic that the article expressed the value of Planck's constant using an SI Unit with kilograms. > Based on 16 months' worth of measurements, it calculated Planck's constant to be 6.626069934 x 10−34 kg∙m2/s.
Interesting fact: this is important for US too, because pound is defined as exactly 0.45359237 kg ( https://en.wikipedia.org/wiki/Pound_(mass)#Current_use )
It's a little ironic that the article expressed the value of Planck's constant using an SI Unit with kilograms. > Based on 16 months' worth of measurements, it calculated Planck's constant to be 6.626069934 x 10−34 kg∙m2/s.
We rearrange the approximation: h = 6.626069934 x 10−34 kg∙m2/s to solve for kg and thus have our definition in terms of h?
It's a little ironic that the article expressed the value of Planck's constant using an SI Unit with kilograms. > Based on 16 months' worth of measurements, it calculated Planck's constant to be 6.626069934 x 10−34 kg∙m2/s.
Right - can somebody explain how this unit of kg-m2/s (weight diffusion? work-seconds?) can be used to define weight? Seem circular.