User blog comment:PitaKang/Funday Monday 3: What would an interstellar civilization look like?/@comment-1789156-20130501205211

Your point about E=mc^2 is wrong.

That equation is used for objects that are not moving, and have no velocity. Assuming that a hypothetical spaceship is infact moving, then you need to use E^2=(mc^2)^2+(pc)^2. This equation uses "p" tp represent momentum. So if the object has no momentum then that section is removed to create E=mc^2. If it has no mass ("m"), such as light, then the mass is zero and its energy is equal to its momentum up to a factor of the speed of a massless particle (btw "c" is commomly called the speed of light simply because light is the most famous massless particle). This means that to be traveling the speed of light, by definition, your mass must be zero. The ratio of the object's velocity becomes closer to the speed of light the less mass it has since V=c*(pc/E). Since photons of light are electromagnetic radiation, this wave packet has no mass, but instead has momentum, p=hf/c, and energy.

I should also mention that the myth that Einstein's theory of special relativity imposes a limit on speed is false. Although it is implied that nothing with mass can break the speed of light, this doesn't mean it is impossible. You can simulate this by pointing a laser or strong light against a far away point, such as the moon, for example. Although the photons of light are traveling to the moon at "c", by moving your wrist the point travels across the surface of the moon, in this axample, 3,500,000 ~ meters in less than one millisecond. To travel that distance it would take light twenty times longer. Although this simple example is an illusion, and nothing is physically moving, this illustrates that this myth is false. Einstein instead said that light travels the same speed in every reference frame.