Finally! A talk about relativity!! I've tried to start threads on this before...
The question of whether or not light can travel at double the speed of light to those observing light from a stationary position is a flawed question. The whole point is that light (C) is a constant and it's just an analogy. We are constantly in motion, even though we appear to have no motion.
All speed is relative to the observer. The speed of your car on the highway (as described by the speedometer) is only relative to the motionless signpost, which is only motionless relative to the objects around it. The signpost is technically spinning around the axis of the Earth at 1,000 MPH, traveling through space at 17,000 miles per hour, like everything else on the planet, relative to the Sun and based only on our units of measurement... Your car, at 70 MPH relative to the signpost is actually something more like 18,070 mph relative to our place in the solar system, right? But even the solar system is moving around the center of the Milky Way at something like 145,000 MPH.... So what's the actual speed of your car on the highway? Is there even such a thing?
Light works similarly, so far as we know, thanks to physics. Standing on the back of a truck, traveling 70 MPH down the road, if you throw a baseball at 70 MPH, the observed speed of the baseball to the signpost is 140 MPH. But it's still just a 70 MPH fastball, as thrown by the guy in the truck. Since only photons can travel at the speed of light, they can't throw baseballs. The point of the analogy is that regardless of our speed, the speed of light is constant. If we traveled much much faster through the Universe, the speed of light would still be what it is, regardless of our relative speed. If we were traveling towards a light source at 1/2 the speed of light, the speed of light wouldn't change. It would still appear to travel at 186,000 miles per second. We know this from all of our astronomical observations. It's essentially infinite, because it's a constant. We won't know if there is anything else beyond the speed of light until we approach the speed of light, which we can never do.