^^This is how the Sun would look from a distance of 4 light-years. If you add all the relativistic effects and stuff, wouldn't the Sun disappear from the visible spectrum? I was told that from a mathematical point of view, it is correct to say that some visible photons would still reach you, but from a physical point of view, and given that the eye needs about 100 photons per second, the Sun does in fact become invisible. Do you guys agree? In this thread, you may treat the Sun as an ideal black-body if you like, but I would also like a consensus on whether the real Sun becomes invisible (to the human eye) or not. Edit: In this thought experiment, like in the previous thread, we are considering traveling towards the Sun at close to the speed of light.