Assuming this 'theory' has validity....I believe it was Darin Morgan who said it is not correct....you are assuming that the air column is 'seeing' the port in the same dimension as you....we look at the cross section physically...we take measurements and calculate a uni-dimensional volume for that very specific point in the port....that is dine assuming that the air is moving.perpendicular to that point...however air very rarely flows with such 'proper' direction...if the line of flow is skewed any amount from perpendicular then it will 'see' the window at an angular view effectively making the area larger....again....science is not exact or cut and dry.....this may be the reason that Darin said this theory lacks a level of validity because we are wrongly interpreting the data....