Two flat glass plates, $10\mathrm{.}0$ cm wide, touch at one end but are separated by a thin wire at the other end, forming a wedge. Light with a wavelength of $450$ nm shines almost perpendicularly on the glass and forms fringes which are $1\mathrm{.}80$ mm apart. What is the diameter of the wire? Two flat glass plates, $10\mathrm{.}0$ cm wide, touch at one end but are separated by a thin wire at the other end, forming a wedge. Light with a wavelength of $450$ nm shines almost perpendicularly on the glass and forms fringes which are $1\mathrm{.}80$ mm apart. What is the diameter of the wire?