Comment Re:No warp drive for you! (Score 3, Informative) 196
There are so many things wrong with your comment I don't event know where to start.
Everything has mass, but light has no REST mass, meaning if it were to stop then it would have no mass, which would be impossible. Electrons and protons for example, and airplanes, do have rest mass so they can stand still. If you take electrons and pump energy into them they start moving faster and faster. If you pump more energy their speed increases, but the closer they get to the speed of light the smaller this increase becomes. There is no limit to the energy they can have, the more you pump the faster they go. If you want to push them from 0.999999c to 0.99999999c, then fine. Also, the mass of any particle is its energy divided by the speed of light squared. That's mass, not rest mass. It increases with speed. For photons which always travel at the speed of light, if you give them more energy they stay at the same speed, but they get heavier. You can also give them as much energy as you want. Finally, if photons had rest mass their speed would vary with their energy just as it happens with electrons. Experiments confirmed with great accuracy that this doesn't happen, i.e. red light from distant stars arrives at the same time as blue light. Please read the Wikipedia article on special relativity, and study the friendly equations, they're not *that* complicated and everything I said is actually very clearly explained by said equations. There's nothing that's unexplained, except maybe why are the equations like that. Answer: because all experiments to date, including this one, fit them. We don't know fundamentally why, that's just how we see the world work when we look closely enough. We keep looking to see if the current equations are possibly slightly wrong and enhance them to fit what we see.