This quaint old building is in Canterbury, England. Presumably it wasn’t always like this, and today we view it with amazement and amusement. We are used to seeing buildings which are ‘built to the square’, with vertical and horizontal lines. But what do these words, horizontal and vertical mean?
If we think of the ground as being a plane, then we have no trouble defining these concepts. A vertical line is one which is perpendicular to the ground. And a horizontal line is one which either lies in the ground plane, or doesn’t meet it at all – that is, is parallel to the ground plane.
But, we know that the earth is round, and the ground is not really a plane at all, but rather a portion of the surface of a sphere. So does this mean that vertical lines are no longer parallel? And horizontal lines – are these really straight lines at all? Perhaps the King’s School Shop has some lessons for us!
