How Does Brian Cox explains the Hubble Law Work?

Galaxies are running away from us because space itself is stretching like a rising loaf of bread.

When we look at distant galaxies, they appear to be moving away faster the farther they are. This is called Hubble's Law. Sir Brian Cox explains this not by saying galaxies are zooming through empty space like cars on a highway, but by showing that the road itself is growing. Imagine you are baking a raisin bread loaf. The dough is the universe, and the raisins are the galaxies. As the dough rises in the oven, every raisin moves away from every other raisin. A raisin far away moves faster than one close to yours because there is more rising dough between them pushing it out.

Think of a rubber band with dots drawn on it. If you pull both ends, the dots spread apart. The dot in the middle stays still relative to itself, but its distance to the other dots increases. This is what happens to space. It is not that galaxies are flying through static space; they are sitting still while the fabric of space expands beneath them.

If you measure how fast a galaxy moves away, you find a simple rule: double the distance, and you get double the speed. This is why we say the universe has an expansion rate. It is like watching people walk out of a party hall. Those near the door take small steps, but those at the back have to stride faster to cover more ground as the hallway stretches. So, when Brian Cox points to the sky, he is not just seeing stars; he is watching the universe grow bigger right before our eyes, carrying galaxies along like raisins in a rising cake.