# Determining the value of the fine-structure constant from a current balance: Getting acquainted with some upcoming changes to the SI

@article{Davis2016DeterminingTV, title={Determining the value of the fine-structure constant from a current balance: Getting acquainted with some upcoming changes to the SI}, author={Richard Davis}, journal={American Journal of Physics}, year={2016}, volume={85}, pages={364-368} }

The revised International System of Units (SI), expected to be approved late in 2018, has implications for physics pedagogy. The ampere definition, which dates from 1948, will be replaced by a definition that fixes the numerical value of the elementary charge e in coulombs. The kilogram definition, which dates from 1889, will be replaced by a definition that fixes the numerical value of the Planck constant h in joule seconds. Existing SI equations will be completely unaffected. However, there… Expand

#### 11 Citations

The Permeability of Vacuum and the Revised International System of Units.

- Physics, Medicine
- IEEE magnetics letters
- 2017

The International System of Units (SI) is expected to be revised such that all seven base units, including the kilogram, will be defined in terms of fixed numerical values of seven defining… Expand

Electromagnetic Units, the Giorgi System, and the Revised International System of Units

- Medicine, Physics
- IEEE Magnetics Letters
- 2018

The redefinition of the ampere in terms of the fixed numerical values of two defining constants could allow for independent experimental measurements of the permeability of vacuum, i.e., determination of the magnetic constant. Expand

From μ0 to e: A Survey of Major Impacts for Electrical Measurements in Recent SI Revision

- Computer Science, Physics
- IEEE Transactions on Instrumentation and Measurement
- 2020

The main impacts of the new SI for electrical measurement activities are surveyed under the new framework. Expand

Three routes to relativistic kinematics and time dilation and their connection to quantum-mechanical path integrals

- Physics
- 2020

The first calculation, similar to that of Lewis of 1908, takes as postulates Newton's Second Law of Motion and work-energy equivalence, the second makes use of the Hamilton-Jacobi equation for motion… Expand

Fine-Structure Constant Connects Electronic Polarizability and Geometric van-der-Waals Radius of Atoms.

- Medicine
- The journal of physical chemistry letters
- 2021

An elementary derivation is presented that accurately predicts the electronic polarizability of atoms A from their geometric van-der-Waals radius RvdW and the FSC α through the compact formula A = (4πε0/a04) × α4/3RvdW7, where ε0 is the permittivity of free space and a 0 is the Bohr radius. Expand

Fine-Structure Constant Connects the Polarizability of Atoms and Vacuum

- Physics
- 2020

We examine the recently derived quantum-mechanical relation between atomic polarizabilities and equilibrium internuclear distances in van der Waals (vdW) bonded diatomic systems [Phys. Rev. Lett.… Expand

Persistence of Electromagnetic Units in Magnetism

- Physics
- 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018)
- 2018

The centimeter-gram-second system of electromagnetic units (EMU) has been used in magnetism since the late 19th century. The International System of Units (SI), a successor to Giorgi's 1901… Expand

Physics 516: Electromagnetic Phenomena (Fall 2019)

- Physics
- 2019

These course notes are made publicly available in the hope that they will be useful. All reports of errata will be gratefully received. I will also be glad to hear from anyone who reads them, whether… Expand

Physics 516: Electromagnetic Phenomena (Spring 2018)

- Physics
- 2018

These course notes are made publicly available in the hope that they will be useful. All reports of errata will be gratefully received. I will also be glad to hear from anyone who reads them, whether… Expand

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