Why is only the observable universe is observable?


Why is only the observable universe is observable?

In: Physics

Because the rest of it is so far away that that light hasn’t reached us yet. It’s further away then something moving at the speed of light can travel in the life span of the universe.

It all has to do with the speed of light and the expansion of the universe.

The universe is only 14 billion-ish years old. The center of our observable universe is earth. We can only see 14 billion light years in any given direction because anything farther away, the light hasn’t reached earth yet.

Also, the universe is expanding at faster than the speed of light. At the “edge” of our observable universe, some of that light will never reach us because the event emitting the light is getting farther as farther away every second creating more space for that light to travel through.

Space is expanding everywhere. The further away you look, the faster space at that location is expanding relative to you. At the limit of the observable universe, about 46 billion light years away, space is expanding at the speed of light, so no information beyond that distance will ever enter the observable universe.