How Far Is the Andromeda Galaxy Really? #deepspace #space #sciencetosleepby

追加: 2026-05-07

[00:00:00]In roughly 100 billion years, every galaxy beyond the local group will have receded beyond the observable horizon.

[00:00:07]Future astronomers, if any exist, will look out into the sky and see nothing but the merged remnant of the Milky Way and Andromeda and its attendant dwarfs floating in an apparently empty cosmos.

[00:00:20]The cosmic microwave background radiation will have been stretched to wavelengths too long to detect. The evidence for the Big Bang, for cosmic expansion, for the existence of other galaxies, will have vanished. A civilization arising in that era would have no way to discover that the universe was ever anything other than a single galaxy surrounded by infinite empty darkness.

[00:00:43]The knowledge that we possess today, knowledge of two trillion galaxies and a cosmos 93 billion light-years across, will be physically inaccessible to them.