# Tag Info

### Confusion on the definition of dielectric permittivity

Dielectric permittivity quantifies how much do the dipoles inside a material want to get polarised ie how much do they want to align with an applied electric field such that the induced electric ...
• 69

### GR and Riemann Surfaces -- does the complex plane have anything to do with it?

This question seems mainly spurred by a conflation of a Riemann surface (which is a 1-dimensional complex manifold), and a (pseudo)Riemannian manifold (which is the underlying geometry of GR).
• 206k

### By what units is 'degradation to ozone layer' measured?

From a freely-available NOAA assessment (Scientific Assessment of Ozone Depletion; 1989, chapter 4 ["Halocarbon Ozone Depletion and Global Warming Potentials"]), page 424: Ozone Depletion ...
• 1,220
1 vote

### How to use the definition of a rank-$2$ tensor for this kind of examples?

Too long for a comment. In the coordinate system where you label your coordinates by $(x,y)$ any $2\times 2$-matrix whose elements are functions of $(x,y)$ gives rise to the four tensors \tag1 a_{...
• 1,839
1 vote

### Confusing definitions of EMF

The formal definition of the electromotive force can be written as follows. $$\mathscr{E} = \sum_{i} \int_{L} \mathbf {f_i} \cdot d\mathbf{l}$$ Where $\mathbf{f_i}$ is the ...
1 vote
Accepted

### What is charge on a fundamental level and what is it caused by?

Electric charge is a fundamental physical property of matter, like mass is a fundamental physical property of matter. Fundamental may be defined as "affecting or relating to the essential nature ...
• 73.5k

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