I remember that, reading Hyperion's cantos, I'd been wondering whether there could be some kind of “altered” physical model which would support Dan Simmons' description of the Doppler effect applied to light. He also describes some phenomenon that could be interpreted as the result of some observer crossing the … “wall of light” (see below).
My question is: how credible is all this, as compared to what happens with sound?
Does anyone know about any research related to that kind of things, or maybe some “physicists” fans of the series already have their own theory?
I'm not sure, but I kind of remember that several of those descriptions are scattered throughout the series. Anyway, here is some relevant excerpt that is (hopefully) short enough to be cited:
Beyond the ship, the universe had contracted into a blue sphere near the bow and a red sphere behind the fins at the stern. I knew enough basic science to have expected a Doppler effect, but this was a false effect, since we had not been anywhere near the speed of light until translation to C-plus and were now far beyond it within the Hawking fold. Nonetheless, the blue and red circles of light — I could make out stars clustered in both spheres if I stared hard enough — now migrated farther to the bow and stern, shrinking to tiny dots of color. In between, filling the vast field of vision, there was … nothing. By that, I do not mean blackness or darkness. I mean void. I mean the sense of sickening nonsight one has when trying to look into a blind spot. I mean a nothing so intense that the vertigo it induced almost immediately changed to nausea within me, racking my system as violently as the transitory sense of being pulled inside out had seconds before.
“My God!” I managed to say, gripping the rail tightly and squeezing my eyes shut. It did not help. The void was there as well. I understood at that second why interstellar voyagers always opted for cryogenic fugue.
Incredibly, unbelievably, Aenea continued playing the piano. The notes were clear, crystalline, as if unmodified by any connecting medium. Even with my eyes closed I could see A. Bettik standing by the door, blue face raised to the void. No, I realized, he was no longer blue … colors did not exist here. Nor did black, white, or gray. I wondered if humans who had been blind since birth dreamed of light and colors in this mad way.
“Compensating,” said the ship, and its voice had the same crystalline quality as Aenea’s piano notes.
Suddenly the void collapsed in on itself, vision returned, and the spheres of red and blue returned fore and aft. Within seconds the blue sphere from the stern migrated along the ship like a doughnut passing over a writing stylus, it merged with the red sphere at the bow, and colored geometries burst without warning from the forward sphere like flying creatures emerging from an egg. I say “colored geometries,” but this does nothing to share the complex reality: fractal-generated shapes pulsed and coiled and twisted through what had been the void. Spiral forms, spiked with their own subgeometries, curled in on themselves, spitting smaller forms of the same cobalt and blood-red brilliance. Yellow ovoids became pulsar-precise explosions of light. Mauve and indigo helixes, looking like the universe’s DNA, spiraled past us. I could hear these colors like distant thunder, like the pounding of surf just beyond the horizon.