Now you're going to define the wormhole. Apply a Layer Mask to the displaced layer. Set your foreground color to black, background to white, and select a soft-edged brush.Now, simply "paint" around the outside of the warp to expose what's underneath it. Remember, painting with black will Mask the area you're painting, painting with white will Reveal the area you're painting. Simply press X to toggle your foreground/background colors, painting in and out until you achieve the look you're going for: