Size of the Universe

I was always under the impression that it was supposed to be impossible for matter to travel faster than the speed of light. We are led to believe that the universe is 13.7 billion years old. So therefore on this basis, the radius of the universe must <= 13.7 billion light years.I was suprised today when I found this web page:Our expanding universe: Age, history & other facts | SpaceIt claims that the diameter of the universe has been calculated at 156 billion light years. If this is true, this means that matter emitting from the big bang must have exceeded the speed of light significantly in order to reach this distance in just 13.7 billion years.Obviously my logic is flawed. Can someone explain please?Ian

Thanks for that. I hadn't realised that space could expand also. I thought that space is supposed to be empty. So it's dificult to envisage 'nothing' expanding. I'll do some digging around on this subject rather than creating a new post on something that's been discussed previously.Thanks again.Ian