We wish to coat a flint glass lens having an anti-reflecting (AR) coating in such a way that visible light (500 nm = 0.500 m) is not reflected from the surface of the lens. MgF2 (having an index of 1.38) is generally the best material for the AR coating due to its low cost and intermediate index of refraction when compared with the flint glass (n = 1.7). Determine how thick this coating must be for 500 nm to experience the least amount of reflection.