The study of physics is the study of the universe-and more specifically, just how the universe works. It is without a doubt the most interesting branch of science, because the universe, as it turns out, is a whole lot more complicated than it looks on the surface (and it looks pretty complicated already). The world works in some weird ways, and through you made need a PhD to understand why, you only need a sense of awe to appreciate how.
According to Einsteins's Theory of Special Relativity, the speed of light can never change-it's always stuck at approximately 300,000,000 meters/second, no matter who's observing it. This in itself is incredible enough, given that nothing can move faster than light, but it's still vey theorectical. The really cool part of special relativity is an idea called dilation, which states, that the faster you go, the slower time passes for you relative to your surroundings. Seriously-if you go take a ride in your car for an hour, you will have aged ever-so-slightly less than if you had just sat at home on your computer. The extra nanoseconds you get out of it might not be worth the price of gas:).