have enhanced the figure a little (here)

]]>I have added a figure (here) showing the schematics of magnetic flux (lines) through a surface.

This figure is grabbed from hyperphysics.phy-astr.gsu.edu/hbase/magnetic/fluxmg.html.

From memory, I was expecting to find a good figure of this kind in either Frankel’s “The geometry of physics” or in Misner, Thorne & Wheeler’s *Gravity* — but looking through both books again, I was surprised that an actual figure showing flux lines/density through a surface is not present in either (the famous “egg-crate figures” of MSW seem more an illustration of the mathematics of exterior calculus than of the physics of flux).

If anyone knows a good illustration of magnetic flux (lines) through surfaces from a canonical (textbook) reference, please let me know.

]]>one possible bit of information at flux

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