“In expanding the field of knowledge we but increase the horizon of ignorance.” -Henry Miller
You know it as the most fundamental law of relativity: that nothing can travel faster than the speed of light. And yet, the observable Universe itself, which has been around for 13.8 billion years since the Big Bang, is now 46.1 billion light years in radius. If everything were contracted down to a tiny volume of space, it seems that such a size would be impossible to achieve. Unless, somehow, space itself were expanding faster than the speed of light.
As it turns out, though, not only is it still true that nothing can travel faster than light, but space itself doesn’t even expand at a speed at all! The reason for the confusion is that space expands at a speed-per-unit-distance, which allows the Universe to expand, light to redshift, and galaxies to appear to recede, all without exceeding the cosmic speed limit at all.