For a long time I have studied and read about whether the photon has mass. On this forum, I could find a link to a document by Gary Oas: On the abuse and use of the relativistic mass. http://arxiv.org/pdf/physics/0504110v2.pdf Oas' paper tells about an investigation done to 164 students: "Einstein also showed that the mass of an object moving at close to the speed of light, as seen by an outside observer, increases. [...] It explains, among other things, why the speed of light serves as the ultimate speed limit in the universe. Suppose you’re in a spaceship, approaching the speed of light. You think ‘I’ll just step on the accelerator a little harder and I’ll pass that pesky speed limit, no problem.’ But it won’t work: to make your craft move faster, you have to use energy; the more massive the spaceship, the more energy you need. And, thanks to Einstein’s special rel- ativity, the mass keeps increasing, so you need more and more energy to further boost the speed. And you’ll never quite make it. If you reached the speed of light, your spaceship, as seen by an outside observer, would have an infinite mass and it would have taken you an infinite amount of energy to get there." I remember that exactly this way I was also introduced into relativity while in school a very long time ago. Oas' paper says that in this way misconceptions develop among first time learners of relativity. Now I began to really wonder, can the concept of relativistic mass really be wrong or out of fashion. I am not an expert on relativity, but how is the ultimate speed limit, the speed of light, now explained if not with velocity dependent mass? If the velocity dependent mass does not prevent a massive object of achieving the speed of light, what is going to do it? The speed of a massive object cannot exceed the speed of light. If the relativistic mass is abandoned and we use instead the energy, the kinetic energy, and if there is no upper limit to how large the kinetic energy can be, doesn't this also mean that the speed of a massive object can exceed the speed of light?