But doing so also meant sacrificing her independence and the risk of losing everything that meant something to her, a potential lifetime of pain.
In dry weather the electric potential in the atmosphere is normally positive relative to the earth, and increases with the height.
What is aimed at in ordinary observations of atmospheric potential is the measurement of the difference of potential between the earth and a point a given distance above it, or of the difference of potential betweeen two points in the same vertical line a given distance apart.
If its potential as observed there is -V (volts), then the potential of the air at the spot occupied by the sphere was +V.
Suppose next that a fixed insulated conductor is somehow kept at the potential of the air at a given point, then the measurement of its potential is equivalent to a measurement of that of the air.