When physicists say nothing can ever attain the speed of light, they are talking of things with mass. Einstein showed that not only do space and time change as speed increases, so does mass. If an object were ever to reach the speed of light its mass would become infinite. Thus, it is argued, nothing can ever attain the speed of light. Nothing, that is, except light.
Light travels at the speed of light.
Einstein's equations would then predict that, from light's own point of view, it travels no distance and takes zero time to do so. This points towards something very strange indeed about the light. As with relativity, the anomaly that sparked this shift concerned light. When you raise the temperature of a metal rod it begins to glows a dull red. As it gets hotter, the color brightens and changes from red to orange, then to white and finally takes on a bluish tinge.