Finding the capacitance of two separated hemispheres

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jiajie
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Homework Statement
an interesting problem to discuss
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How to calculate a pair of adjacent hemispheres capacitance?
like the picture, two adjacent hemispheres(radius R, distance d, assume the charge is ±Q of each side(assume evenly distributed), can we calculate its capacitance?
 
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  • Hand-drawn diagram of two hemispheres facing each other, each with radius R, with their flat centres separated by distance d along a horizontal line.
    IMG_20210516_212925_edit_27864824671788.jpg
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The assumption of uniformly distributed charge doesn't lead to equipotential hemispheres. In this case, calculating the capacitance isn't an easy task.
 
Gordianus said:
The assumption of uniformly distributed charge doesn't lead to equipotential hemispheres. In this case, calculating the capacitance isn't an easy task.
They can't be conductors, so I don't think there is any standard definition of capacitance.
 
can we assume the electrical field is horizontally paralleled to simply it
 
jiajie said:
can we assume the electrical field is horizontally paralleled to simply it
Unfortunately, it isn't that simple. I checked whether Smythe had addressed this case but I had no luck.