The popular explaination of why an object can't travel the speed of light is because the objects mass will increase to infinity and then it would take an infinite force to push it. What if this is not the case? Galaxies travel away from us now at speeds close to the speed of light and I don't feel any heavier than I did before I noticed this. So what if mass increase was only relative to the observer? If we only measure the objects mass in space compared to the objects that they are in orbit with then that would only take into account the mass of the to objects relative to each other? But, did they take into account that it could have a stronger gravitational pull relative to only other objects that where traveling the speed of light relative to it?