An expanding universe makes distance harder to define because space keeps growing while light is in transit. Doesn’t that imply that the universe is expanding faster than light? That’s because the speed limit of light only applies to local observations – I’ll never see a rocket ship blast by me faster than light. And in an expanding universe, more distant objects recede faster and faster, because there’s more space between them and us to expand. And the turnover point, where objects will recede away from us faster than light, is right at the Hubble distance, 13.77 billion light-years away.