# Why cant information and forces travel faster than the speed of light when they aren't mass?

I understand why the speed of light is a constant in all reference frames, and the reason behind why the mass of an object increases as it approaches the speed of light.( Since the added energy has to go somewhere it turns out to be just mass.) Now, due to this and the fact that we require infinite energy to reach the speed of light, we will never be able to do that. But, people also seem to be talking about information and forces(like the electrostatic force) not being able to travel faster than the speed of light. I dont understand this statement.It is not mass anyway, then why is it restricted by the speed of light? (I AM NOT TALKING ABOUT QUANTUM ENTANGLEMENT, SINCE WE DON'T KNOW MUCH ABOUT IT;ALL CLASSICAL)

• and the reason behind why the mass of an object increases as it approaches the speed of light This is not the way to view this situation. Please read: Invariant Mass – user140606 Jan 27 '17 at 18:28
• The invariance of the speed of light is a restriction on causality itself! Nothing to do necessarily with mass or energy! – user12029 Jan 27 '17 at 18:49
• But I don't understand why? for particles with mass its quite simple but why does it restrict the electrostatic force?gravity? etc. – Chandrahas Jan 28 '17 at 2:51
• Mass and energy are similar. A force comes from a field, and it has energy. As for information, it's always about the physical means of having it go from here to there. It needs to be carried by some physical thing, i.e. Energy. So it also doesn't go faster than light. – Bob Bee Jan 28 '17 at 4:30
• If you can send information, in any form, faster than light, then it is trivial to send it into your own past. – tfb Jan 28 '17 at 14:43