We know that the mass of any body turns to zero as it gains the velocity of light. From Einstein's Mass-Energy relation, E=mc2 so that, m=E/c2 It is clear that mass is directly proportional to energy. For a body to gain light's speed, we have to apply infinite amount of energy to the body to accelerate it. So, the mass of the body also increases in large amount till it attained the velocity of light. From this, it is clear that the body will have maximum mass just a moment ago when it gains the velocity of light. As soon as it gains the velocity of light, how does all the mass change to zero? Doesn't it should have more mass?