My talk today sort of comes from the unreal side of the world in the sense that this method of nondestructive testing is quite new and nobody has used it, and I am presenting this method as a possible method for the future. Of course, the unreal world today often becomes the real world tomorrow, so there is a good possibility that the method that I present here will become a useful one. At the moment, of course, the equipment that I use for these measurements can't be hung on the airplane wing or anything of that sort.