11. Instead of being smooth, their retina is composed of tiny cups, acting like parabolic mirrors . 12. Using a parabolic mirror , he would hang contrasting pairs of painted shapes, which rotated freely. 13. Sound waves may be " viewed " using parabolic mirrors and objects that produce sound. 14. A parabolic mirror would have varying error of a spherical mirror is uniform in every direction. 15. The rays then reflect off of a parabolic mirror , which focuses all the rays to a point. 16. In 1842 it was updated with a colza oil lamp and in 1849 parabolic mirrors were installed. 17. The observatory originally contained the Rayna Telescope, an f / 4.5 parabolic mirror ground by John Owen. 18. These consist of two opposing parabolic mirrors , with an opening in the center of the top mirror. 19. A parabolic mirror is used as the reflector, with a bulb at the focus, in a searchlight. 20. Its eyes use a combination of photonic crystals, parabolic mirrors and a clustered arrangement of rods and cones.
