The electric blue arcs
making up the spectacular egg-like shape framing these objects are a result of the galaxy cluster's immense gravity.
If you look at the right edge of a small red light in an otherwise dark field with a partly dark-adapted right eye, you will momentarily see faint blue arcs curving away from the light toward the right (see Figure 10).
You can easily see the blue arcs at night in your home in a room with some red LED indicator lights on equipment.
You can locate the optic disk by noting where the blood vessels originate or the blue arcs terminate in Activities 6 and 10, respectively If you keep one eye closed and blink with the other eye while looking at a uniformly illuminated surface (such as the inner surface of a ping pong ball cut in half to fit over the eye), you may see a gray disk at the location of the optic disk (Palmer, 1991).
Purkinje first noticed entoptic sensations of blue arcs in 1825.
It was only when the arrangement of the optic nerve and retinal nerve fibres was described by Wallace in 1836 that Muller was in 1855 able to fit this anatomical relationship together with the blue arc sensations.
2 blue arcs
in planar subgraph: 16 red arcs in planar subgraph: 4 vrtx permut: 4 5 6 7 vrtx permut: 2 1 9 8 blue arcs
: 1 2 3 5 7 blue arcs
: 11 12 13 14 15 blue arcs
: 16 17 18 19 21 blue arcs
: 22 red arcs: 6 8 9 20
By hypothesis, y [not equal to] t, so P contains no blue arcs.
If P contains no blue arcs, then it is a path in the original graph, contradicting the claim that z = idom(x).
The original version of the map, which was released three years ago, shows most of the world illuminated by transcontinental friendships, with oceans dominated by blue arcs
of light, metro.
Red Bermudas, 1978-80, is on the plus side of this practice: its set of thin, curving blue arcs corresponds interestingly to the sequence of delicate step-back moldings that the arcs pass over.
In Red Bermudas, for example, he brushes blue arcs over a layer of contrasting orange; he also juxtaposes these arcs with repetitive patterns of large dots of yellow-green and orange-brown.