I have been doing a lot of reading about this and it seems really, really interesting. Correct me if I am wrong on any of this, but I'm going to attempt to summarize how traveling at the speed of light, or at least 99.998 percent the speed of light, would look in two different cases: in interstellar space, and on the surface of Mars. Okay, so on Mars, as your vehicle suddenly and somehow accelerates to 99.998 percent the speed of light, light from objects towards the center of your vision appear to shift into the bluer part of the spectrum. Meanwhile, light from objects farther out from your center of vision appear to become more red shifted. This eventually results in your view of the world turning into a tiny circle of bright, blue shifted light directly in front of you, and a surrounding background of blackness outside of that since the wavelengths would shift into infrared. Now in interstellar space, as your ship reached 99.998 percent the speed of light, pretty much the same kind of event would occur. The universe in front of you becomes more blue shifted, including light from neighboring stars; this means that eventually the light coming from those stars would shift into the X-ray range, no longer visible to you. However, light from the cosmic microwave background would shift into the visible spectrum, causing a bright white disk of light to appear in front of you. All light from other stars will still be there, again, (hence X-ray) but with too much energy to be perceived as optical; so the universe around the center of your vision basically fades into complete blackness while the universe at your center of vision becomes brighter and brighter as the CMB actually becomes visible. Light from stars farthest out to your center of vision probably just shift out into infrared too, on the other hand, but the blue shift towards the center becomes much more noticeable. Was that accurate, and if so, what other effects would you notice that I might not know about yet? I'd like to know because this stuff is very cool!