Reading this response https://astronomy.stackexchange.com/questions/10538/when-the-universe-expands-does-it-create-new-space-matter-or-something-else I understand Universe is not expanding like if it is *stretching its space*, but it is actually adding space that matter can travel through. So, if the Universe can *create* more space, and space and time are related, shouldn't that mean Universe is *creating* also more *time*? And if it is the case, shouldn't this effect alter results of our measurements about how much time light spends to reach us from distant stars? We know that photons have no mass, travel at speed of light, and time has no sense for them. But at the same time they are influenced in their trajectories by folds in the space-time. If gravity deforms space-time, shouldn't an expanding Universe *adding new space* doing the same? Shouldn't the Universe create gravitational waves by its own, like other objects inside the Universe?