does the spacing between fringes in a two-slit interference pattern increase, decrease, or stay the same if (a) the slit separation is increased, (b) the color of the light is switched from red to blue, and (c) the whole apparatus is submerged in cooking sherry? (d) if the slits are illuminated with white light, then at any side maximum, does the blue component or the red component peak closer to the central maximum?