Most of us know that Einstein came up with the theory that superluminal speed was impossible. And most physicists nowadays believe that and have accepted that as fact. I just want to know if this is a technically correct way of stating this: Light travels at approx. 299,800 km/s in a vacuum. And "light" can be described as being composed of (in some senses) photons. Massless particles that travel as particles AND waves. Now, since these particles are massless, they travel at the speed of light. All of it's energy can be used for "traveling the speed of light." And for mass to exist, that mass needs to have a energy content. That energy content cannot be used for the "motion" which would be traveling at the speed of light, so therefore, that particle with mass just doesn't have enough energy that can be used in motion to travel faster than the speed of light. Now, I know I'm thinking in a very mechanical sense, thinking of particles' energy contents as used for motion and whatnot, but is that technically a correct way of stating that? And if not, what would be a more correct way of stating that? Or is this statement just completely wrong, and I should just completely drop this notion completely?