Michael Mozina claimed he could
see a solid feature underneath 7200 kilometers of what he believes to be transparent plasma lying "below the photosphere/chromosphere boundary". Because that alleged solid feature was at the limb of the sun, he wasn't looking at it straight down through 7200 kilometers of alleged plasma; he was looking at it from the side, through all the alleged plasma that lies between the intersection of the sun's surface with his line of sight and the alleged solid feature at the limb. We want to calculate how much alleged plasma lies along his line of sight.
If we assume the camera lies along the z-axis, so far away that it doesn't melt, and choose a coordinate system that positions his alleged solid feature at 3 o'clock, then his line of sight is well approximated by the line determined by x=(r - 7200km) and y=0km, where r is the radius of the sun. The distance we're looking for is the difference between the z-coordinate of the alleged solid feature and the z-coordinate of the intersection of the sun's surface with that line.
The z-coordinate of the alleged solid feature is 0km, because
Michael Mozina thinks he's viewing it in profile.
Recall that the z-coordinate at which the
sphere's surface intersects with any line parallel to the z-axis is given by equation (1) below. The distance we want is therefore given by equation (2).
This calculation can be duplicated in the laboratory using a sufficiently precise scale model. Its principle can be demonstrated in the kitchen using a spherical melon and a metal straw. (By injecting vodka or similar reagents, the investigator can imbibe his/her own math bunny.)
I'd be interested in that.