11. In particular, the interference fringes seen in the double-slit experiment require repeated trials to be observed. 12. The interference fringes form perpendicular to this wedge. 13. The resulting interference fringes are so small that they can only be seen through a microscope. 14. The interference fringe maxima occur at angles 15. White light interference in a soap bubbleIt is also possible to observe interference fringes using white light. 16. The method can be realized as the method of holographic addition and subtraction in an interference fringe . 17. The interference fringes typically only form once the optical flat begins to wring to the testing surface. 18. Thus the second detector can no longer determine which path was taken, and the interference fringes are restored. 19. If both surfaces are perfectly the same flatness and parallel to each other, no interference fringes will form. 20. He saw no shift of the interference fringes , corresponding to an upper limit of \ Delta v km / s.