I was just thinking, once an object has a certain critical mass( or is it density?) it will turn into a black whole. The faster you go the larger your relative mass will get. If you go fast enough could you turn into a black whole. ( also, is your mass increase only relative to an slower moving observer. If it is, could their be such a thing as a relative blackhole.... [suddely goes cross eyed and has a pounding headache} mabey am thinking to hard, or not enough. if some one could clearn this up for me i would greatly appreate it.