This sentence is very interesting. That is to say, first, although the speed of light propagation is the fastest, it is also limited. Second, compared with the vast universe, even the fastest speed of light makes an instant long.

Besides, the nearest extragalactic galaxy is not Andromeda, but the Large Magellanic Cloud. In our local galaxy group, the distance between Andromeda and us is 2.5 million light years, while the Large Magellanic Cloud (a dispersed galaxy in our local galaxy group) is only 6.5438+0.6 million light years, which is the nearest extragalactic galaxy. It's just that Andromeda galaxy is so famous that it left a deep impression on us.