Two glass plates touch at one end and are separated by a piece of paper at the other end forming an air wedge. Assume that green light (vacuum wavelength =552 nm) strikes the glass plates nearly perpendicularly. Determine the number of bright fringes that occur between the place where the plates touch and the edge of the sheet of paper between the plates (thickness = 4.10 X 10-5 m). Also, explain why there is a dark fringe where the plates touch.